tag:blogger.com,1999:blog-75986154557124029732024-03-25T11:14:46.843-04:00PolymathRobert Clarkhttp://www.blogger.com/profile/16114043697010364282noreply@blogger.comBlogger183125tag:blogger.com,1999:blog-7598615455712402973.post-79044587665265343532024-03-03T12:56:00.005-05:002024-03-03T17:27:38.910-05:00SpaceX should explore a weight-optimized, expendable Starship upper stage.<p style="text-align: center;"><i> Copyright 2024 Robert Clark</i></p><div><i><span style="font-family: inherit;"><br /></span></i><span style="font-family: inherit;"> T<span style="-webkit-text-size-adjust: auto;">o me it’s just stunning SpaceX is ignoring that an expendable Starship could be done for 40 ton dry mass, choosing instead the current 120 tons for the reusable version: </span></span></div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"><br /></span></span></div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"><br /></span></span></div><div><article aria-labelledby="id__5q4gupthf3 id__dnftyhyadru id__uz6jhik9q3 id__uiqvr896sgq id__b75oci4pg6u id__qmku7e05ml id__5y0uyfcdcmf id__mhgdivud8a9 id__glc7kxhclm id__zwyoyebbwg id__f0pflifi4o id__xcacopl1uc id__6tsobtz9q4b id__7zleob19r16 id__bukyc2mwcx7 id__864n9eoemiq id__7vlz9zspwnd id__2mr4n1ha57w id__5qvb25h712b" class="css-175oi2r r-18u37iz r-1udh08x r-i023vh r-1qhn6m8 r-1ny4l3l" data-testid="tweet" role="article" style="-webkit-tap-highlight-color: rgba(0, 0, 0, 0); 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min-width: 0px; overflow-wrap: break-word; padding: 0px; text-align: inherit; text-overflow: unset; white-space: inherit;">Elon Musk</span></span></div><div class="css-1rynq56 r-bcqeeo r-qvutc0 r-37j5jr r-a023e6 r-rjixqe r-16dba41 r-xoduu5 r-18u37iz r-1q142lx" dir="ltr" style="border: 0px solid black; box-sizing: border-box; color: #0f1419; display: inline-flex; flex-direction: row; flex-shrink: 0; font-family: TwitterChirp, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif; font-stretch: normal; line-height: 20px; list-style: none; margin: 0px; min-width: 0px; overflow-wrap: break-word; padding: 0px; text-align: inherit; text-overflow: unset; white-space: pre-wrap;"><span class="css-1qaijid r-bcqeeo r-qvutc0 r-poiln3 r-1awozwy r-xoduu5" style="align-items: center; border: 0px solid black; box-sizing: border-box; display: inline-flex; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant-caps: inherit; line-height: inherit; 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box-sizing: border-box; color: #536471; display: inline; flex-direction: row; font-family: TwitterChirp, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif; font-feature-settings: "ss01"; font-stretch: normal; line-height: 20px; list-style: none; margin: 0px; max-width: 100%; min-width: 0px; overflow-wrap: break-word; overflow: hidden; padding: 0px; text-align: inherit; text-overflow: unset; white-space: nowrap;"><span class="css-1qaijid r-bcqeeo r-qvutc0 r-poiln3" style="border: 0px solid black; box-sizing: border-box; display: inline; font-family: inherit; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant-caps: inherit; line-height: inherit; list-style: none; margin: 0px; min-width: 0px; overflow-wrap: break-word; padding: 0px; text-align: inherit; text-overflow: unset; white-space: inherit;">@elonmusk</span></div></a></div></div></div></div></div></div><div class="css-175oi2r r-1jkjb" style="align-items: stretch; border: 0px solid black; 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z-index: 0;"><div class="css-175oi2r" style="align-items: stretch; border: 0px solid black; box-sizing: border-box; display: flex; flex-basis: auto; flex-direction: column; flex-shrink: 0; list-style: none; margin: 0px; min-height: 0px; min-width: 0px; padding: 0px; position: relative; z-index: 0;"><div class="css-175oi2r r-1s2bzr4" style="align-items: stretch; border: 0px solid black; box-sizing: border-box; display: flex; flex-basis: auto; flex-direction: column; flex-shrink: 0; list-style: none; margin: 12px 0px 0px; min-height: 0px; min-width: 0px; padding: 0px; position: relative; z-index: 0;"><div class="css-1rynq56 r-bcqeeo r-qvutc0 r-37j5jr r-1inkyih r-16dba41 r-bnwqim r-135wba7" data-testid="tweetText" dir="auto" id="id__f0pflifi4o" lang="en" style="border: 0px solid black; box-sizing: border-box; color: #0f1419; display: inline; font-family: TwitterChirp, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif; font-size: 17px; font-stretch: normal; line-height: 24px; list-style: none; margin: 0px; min-width: 0px; overflow-wrap: break-word; padding: 0px; position: relative; text-align: inherit; text-overflow: unset; white-space: pre-wrap;"><span class="css-1qaijid r-bcqeeo r-qvutc0 r-poiln3" style="border: 0px solid black; box-sizing: border-box; display: inline; font-family: inherit; font-size: inherit; font-stretch: inherit; font-variant-caps: inherit; line-height: inherit; list-style: none; margin: 0px; min-width: 0px; overflow-wrap: break-word; padding: 0px; text-align: inherit; text-overflow: unset; white-space: inherit;"><i>Probably no fairing either & just 3 Raptor Vacuum engines. Mass ratio of ~30 (1200 tons full, 40 tons empty) with Isp of 380. Then drop a few dozen modified Starlink satellites from empty engine bays with ~1600 Isp, MR 2. Spread out, see what’s there. Not impossible.</i></span></div></div></div><div class="css-175oi2r" style="align-items: stretch; border: 0px solid black; box-sizing: border-box; display: flex; flex-basis: auto; flex-direction: column; flex-shrink: 0; list-style: none; margin: 0px; min-height: 0px; min-width: 0px; padding: 0px; position: relative; z-index: 0;"></div><div class="css-175oi2r" style="align-items: stretch; border: 0px solid black; box-sizing: border-box; display: flex; flex-basis: auto; flex-direction: column; flex-shrink: 0; list-style: none; margin: 0px; min-height: 0px; min-width: 0px; padding: 0px; position: relative; z-index: 0;"></div><div class="css-175oi2r r-1r5su4o" style="align-items: stretch; border: 0px solid black; box-sizing: border-box; display: flex; flex-basis: auto; flex-direction: column; flex-shrink: 0; list-style: none; margin: 16px 0px; min-height: 0px; min-width: 0px; padding: 0px; position: relative; z-index: 0;"><div class="css-175oi2r r-k4xj1c r-18u37iz r-1wtj0ep" style="align-items: start; 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text-decoration: none; text-overflow: unset; white-space: nowrap;"><time datetime="2019-03-30T01:14:51.000Z">9:14 PM · Mar 29, 2019</time></a></div></div></div><div class="css-175oi2r r-18u37iz" style="align-items: stretch; border: 0px solid black; box-sizing: border-box; display: flex; flex-basis: auto; flex-direction: row; flex-shrink: 0; list-style: none; margin: 0px; min-height: 0px; min-width: 0px; padding: 0px; position: relative; z-index: 0;"></div></div></div><div class="css-175oi2r" style="align-items: stretch; border: 0px solid black; box-sizing: border-box; display: flex; flex-basis: auto; flex-direction: column; flex-shrink: 0; list-style: none; margin: 0px; min-height: 0px; min-width: 0px; padding: 0px; position: relative; z-index: 0;"><div class="css-175oi2r" style="align-items: stretch; border: 0px solid black; box-sizing: border-box; display: flex; flex-basis: auto; flex-direction: column; flex-shrink: 0; list-style: none; margin: 0px; min-height: 0px; min-width: 0px; padding: 0px; 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Then that 80 tons difference in the dry mass between the reusable and expendable versions is a huge difference. </span></span></div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"><br /></span></span></div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"> Now, note because of size, that, just like with the Falcon 9, the 1st stage is 2/3rd of the cost. So for ~$90 million total for the SuperHeavy/StarShip, the SuperHeavy is $60 million of that. But as the Falcon 9 shows it is much easier to get reusable 1st stage. So assume with reuse of SuperHeavy, its cost, is now, say, $5 million per launch. Now it’s a $35 million total cost for the partially reusable SuperHeavy/StarShip. BUT now because of the radically reduced upper stage dry mass, we have ca. 300 tons payload this version!(Assume SuperHeavy lands down range if you wish to maintain the high payload.) <b>But this is about the same cost per kilo as fully reusable 100 to 150 ton payload fully reusable version at $10 million per flight cost.</b></span></span></div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"><br /></span></span></div><div><span style="-webkit-text-size-adjust: auto;"><span style="font-family: inherit;"> Then the question is how realistic is it the Starship could have 40 ton dry mass as an expendable? I think it is quite realistic. </span></span></div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"><br /></span></span></div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"> Consider the original Atlas rocket first used to send John Glenn to orbit:</span></span></div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"><br /></span></span></div><div><p class="p1" style="-webkit-text-size-adjust: auto; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s1" style="font-style: italic; text-decoration: underline;"><span style="font-family: inherit;">SLV-3 Atlas / Agena B.</span></span></p><p class="p1" style="-webkit-text-size-adjust: auto; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s2" style="font-style: italic;"><span style="font-family: inherit;">Family: Atlas. Country: USA. Status: Hardware. Department of Defence Designation: SLV-3.</span></span></p><p class="p1" style="-webkit-text-size-adjust: auto; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s2" style="font-style: italic;"><span style="font-family: inherit;">Standardized Atlas booster with Agena B upper stage.</span></span></p><p class="p1" style="-webkit-text-size-adjust: auto; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s2" style="font-style: italic;"><span style="font-family: inherit;">Specifications</span></span></p><p class="p1" style="-webkit-text-size-adjust: auto; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s2" style="font-style: italic;"><span style="font-family: inherit;">Payload: 600 kg. to a: 19,500 x 103,000 km orbit at 77.5 deg</span></span></p><p class="p1" style="-webkit-text-size-adjust: auto; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s2" style="font-style: italic;"><span style="font-family: inherit;">inclination trajectory.</span></span></p><p class="p1" style="-webkit-text-size-adjust: auto; font-stretch: normal; line-height: normal; margin: 0px;"><span style="font-family: inherit;"><span class="s1" style="font-style: italic; text-decoration: underline;">Stage Number: 0.</span><span class="s2" style="font-style: italic;"> 1 x Atlas MA-3 Gross Mass: 3,174 kg. Empty Mass:</span></span></p><p class="p1" style="-webkit-text-size-adjust: auto; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s2" style="font-style: italic;"><span style="font-family: inherit;">3,174 kg. Thrust (vac): 167,740 kgf. Isp: 290 sec. Burn time: 120 sec.</span></span></p><p class="p1" style="-webkit-text-size-adjust: auto; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s2" style="font-style: italic;"><span style="font-family: inherit;">Isp(sl): 256 sec. Diameter: 4.9 m. Span: 4.9 m. Length: 0.0 m.</span></span></p><p class="p1" style="-webkit-text-size-adjust: auto; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s2" style="font-style: italic;"><span style="font-family: inherit;">Propellants: Lox/Kerosene No Engines: 2. LR-89-5</span></span></p><p class="p1" style="-webkit-text-size-adjust: auto; font-stretch: normal; line-height: normal; margin: 0px;"><span style="font-family: inherit;"><span class="s1" style="font-style: italic; text-decoration: underline;">Stage Number: 1.</span><span class="s2" style="font-style: italic;"> 1 x Atlas Agena SLV-3 </span><span class="s3" style="font-style: italic; font-weight: bold;">Gross Mass: 117,026 kg.</span></span></p><p class="p1" style="-webkit-text-size-adjust: auto; font-stretch: normal; line-height: normal; margin: 0px;"><span style="font-family: inherit;"><span class="s3" style="font-style: italic; font-weight: bold;">Empty Mass: 2,326 kg.</span><span class="s2" style="font-style: italic;"> Thrust (vac): 39,400 kgf. Isp: 316 sec. Burn time: 265 sec. Isp(sl): 220 sec. Diameter: 3.1 m. Span: 4.9 m. Length:</span></span></p><p class="p1" style="-webkit-text-size-adjust: auto; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s2" style="font-style: italic;"><span style="font-family: inherit;">20.7 m. Propellants: Lox/Kerosene No Engines: 1. LR-105-5</span></span></p><p class="p1" style="-webkit-text-size-adjust: auto; font-stretch: normal; line-height: normal; margin: 0px;"><span style="font-family: inherit;"><span class="s1" style="font-style: italic; text-decoration: underline;">Stage Number: 2.</span><span class="s2" style="font-style: italic;"> 1 x Agena B Gross Mass: 7,167 kg. Empty Mass: 867 kg. Thrust (vac): 7,257 kgf. Isp: 285 sec. Burn time: 240 sec. Isp(sl): 0 sec. Diameter: 1.5 m. Span: 1.5 m. Length: 7.1 m. Propellants: Nitric</span></span></p><p class="p1" style="-webkit-text-size-adjust: auto; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s2" style="font-style: italic;"><span style="font-family: inherit;">acid/UDMH No Engines: 1. Bell 8081</span></span></p><p class="p1" style="-webkit-text-size-adjust: auto; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s4"><a href="http://www.friends-partners.org/partners/mwade/lvs/slvgenab.htm"><span style="font-family: inherit;">http://www.friends-partners.org/partners/mwade/lvs/slvgenab.htm</span></a></span></p></div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"><br /></span></span></div><div><span style="-webkit-text-size-adjust: auto; font-family: inherit;"> The Atlas had an unusual design however. It dropped its main lift-off engine at altitude and continued on with what was called the “sustainer” engine. This engine due to much of the propellant mass being burned off had much lower thrust, and so much reduced required engine weight. Then looking at the specifications of this stage, note it had nearly a 50 to 1 mass ratio(!)</span></div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"><br /></span></span></div><div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"> The comparison of this sustainer stage to the 3-engine Starship upper stage is appropriate since an upper stage typically doesn’t need to have the thrust of a stage needing to lift off from the ground. Weight growth of the Starship now at 120 tons dry mass required adding 3 additional engines, to now have 6 engines.</span></span></div></div><div><br /></div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"> However, a key reason why the Atlas was able to achieve such a high mass ratio was that it used what was called “balloon-tank” design. This was a design that used pressurization to maintain its structure even on the ground. It would actually collapse under its own weight when not pressurized.</span></span></div><div><div><br /></div></div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"> However, methanolox is at about 80% of the density of kerolox. So a corresponding methanolox version would be at 40 to 1 mass-ratio, better than the 30 to 1 mass ratio Elon suggested. But its not likely SpaceX would want to deal with the operational difficulties of having a stage be continually pressurized even when on the ground, unfueled, especially for a stage intended to have high launch rates.</span></span></div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"><br /></span></span></div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"> So I’ll look at another stage, the S-II hydrolox 2nd stage of the Saturn V rocket. </span><span style="-webkit-text-size-adjust: auto;">The Saturn V launcher of the Apollo program was remarkable in the lightweight features of its upper stages, the</span><span style="-webkit-text-size-adjust: auto;"> </span><a href="http://en.wikipedia.org/wiki/S-II" style="-webkit-text-size-adjust: auto;">S-II</a><span style="-webkit-text-size-adjust: auto;"> </span><span style="-webkit-text-size-adjust: auto;">and the</span><span style="-webkit-text-size-adjust: auto;"> </span><a href="http://en.wikipedia.org/wiki/S-IVB" style="-webkit-text-size-adjust: auto;">S-IVB</a><span style="-webkit-text-size-adjust: auto;">. This page gives a list of the fueled weights and empty weights of the Saturn V stages:</span></span></div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"><br /></span></span></div><p class="p1" style="-webkit-text-size-adjust: auto; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s1"><span style="font-family: inherit;">Ground Ignition Weights</span></span></p><p class="p1" style="-webkit-text-size-adjust: auto; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s1"><span style="font-family: inherit;"><a href="http://history.nasa.gov/SP-4029/Apollo_18-19_Ground_Ignition_Weights.htm">http://history.nasa.gov/SP-4029/Apollo_18-19_Ground_Ignition_Weights.htm</a></span></span></p><p class="p1" style="-webkit-text-size-adjust: auto; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s1"><br /></span></p><p class="p1" style="-webkit-text-size-adjust: auto; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s1"><span style="font-family: inherit;"> The later versions of Apollo had improved weight optimization. We'll use the specifications for Apollo 14. The "Ground Ignition Weights" page gives the Apollo 14 S-II dry weight as 78,120 lbs., 35,510 kg, and gross weight as 1,075,887 lbs., 489,040 kg, for a propellant mass of 997,767 lbs., 453,530 kg, resulting in a mass ratio of 13.77 to 1. </span></span></p><div><span style="-webkit-text-size-adjust: auto;"><span style="font-family: inherit;"><br /></span></span></div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"> Now, methanolox is 2.5 times greater density than hydrolox. Then the corresponding mass ratio for methanolox would be at 33 to 1. This comparison is particularly apt because the mass in the same size tanks would be approx. at the 1,200 propellant mass of the Starship.</span></span></div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"><br /></span></span></div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"> So Starship could reach ca. 30 to 1 mass ratio when using the weight optimizing methods used during the Apollo program.</span></span></div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"><br /></span></span></div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"> But if the price per kilo of this partially reusable version would be at about what the current version is what is the advantage? One advantage is as mentioned is you would not have the difficulty of making the upper stage reusable, no problematical heat shield tiles.</span></span></div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"><br /></span></span></div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"> There is another advantage not as concrete, but in my mind just as important if not more so. In my opinion the approach SpaceX is taking with the SuperHeavy/Starship is ill-conceived. It is based on the idea the SuperHeavy/Starship should be the be-all-end-all for ALL of spaceflight.</span></span></div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"><br /></span></span></div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"> But if you look at transport methods throughout history even going back to the horse-drawn era transports always came in different sizes. A comparison to the air traffic is most instructive. It turns our the largest air transports the jumbo-jet size aircraft actually make up a tiny percentage of air traffic. The great bulk of air traffic is carried by smaller aircraft.</span></span></div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"><br /></span></span></div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"> And even looking at SpaceX’s own Falcon Heavy demonstrates this. The per kilo cost is less than that of the Falcon 9. But the number of Falcon Heavy flights is tiny compared to the number of Falcon 9 flights.</span></span></div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"><br /></span></span></div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"> The fixation on the reusable Starship as the be-all-end-all for all spaceflight also leads to the poorly-conceived notion that a Mars or Moon mission must be carried out by multiple refuelings of the reusable Starship. The number of refueling flights for the Artemis lunar missions might be 8 to 16 flights.</span></span></div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"><br /></span></span></div><div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;">But it is a basic principle of orbital mechanics that high delta-v missions such as to the Moon or Mars are more efficiently carried out by using additional stages. Simply by giving the SuperHeavy/Starship an additional 3rd stage, flights to both the Moon and to Mars could be carried out in a <i>single launch</i>.</span></span></div></div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"><br /></span></span></div><div><div><span style="-webkit-text-size-adjust: auto; font-family: inherit;"> An expendable Starship would mean it being regarded as just another stage. And a 3rd stage could be set atop it as needed, such as for high delta-v missions. </span></div></div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"><br /></span></span></div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"> As another illustration of the fact this approach to the SuperHeavy/Starship is ill-conceived, the payload of the SH/ST to GEO is nearly zero because that Starship dry mass is so high. This is the most lucrative satellite market, but a single SH/ST launch could not service that market. In order to just launch satellites to GEO the SH/ST would have to do multiple refuelings just to launch a satellite to GEO, just like when it had to launch manned interplanetary missions. This is an odd state of affairs for a rocket simply to launch satellites to GEO.</span></span></div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"><br /></span></span></div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"> Or of course it could utilize a 3rd stage. But if you are going to use a third stage then, why not just use it also for the manned interplanetary missions that would allow you to do such missions in a single flight?</span></span></div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"><br /></span></span></div><div><span style="-webkit-text-size-adjust: auto; font-family: inherit;"> Robert Clark</span></div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"><br /></span></span></div><div><span style="font-family: inherit;"><span style="-webkit-text-size-adjust: auto;"><br /></span></span></div>Robert Clarkhttp://www.blogger.com/profile/16114043697010364282noreply@blogger.com0tag:blogger.com,1999:blog-7598615455712402973.post-44558217871579045092024-02-29T16:43:00.000-05:002024-02-29T16:43:04.622-05:00Altitude compensation is more efficient than staged-combustion engines.<p style="text-align: center;"><i> Copyright 2024 Robert Clark</i></p><p style="text-align: center;"><i><br /></i></p><p style="text-align: left;"><i> </i>Staged combustion engines such as the Russian RD-180 and American SSME are regarded as the utmost in efficiency because they achieve high vacuum Isp while being able to achieve high thrust at sea level. They achieve this by operating at high chamber combustion pressure. </p><p style="text-align: left;">SpaceX is developing the Raptor engine also as a staged combustion engine. However, a surprising fact is a medium performance, mid-level pressure and cheaper engine such as the Ariane 5’s Vulcain engine or Delta IV’s RS-68 can get higher performance than a staged combustion engine by using altitude compensation.</p><p style="text-align: left;">See the graphic of the Isp of the Vulcain engine with an altitude compensating nozzle:</p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEji__YHQjcZV_FRL1ZT1T2pl-qFg1v8VFdRakHQSDrvKbiULFTHv2sZHqjei8ywiXE6WVTLBbaGq0_Vv3EzXyBndHeECj4QfqYepZg-5VKIX9zj2zxr1LJho4Q-RcmVFibd44PjmleCp-bhvsnsMra6SRPZaDCDm5mm9PSRDUVYbjpoMPhtutGF0GDX0lU/s1472/15795F8B-4C87-4664-8B18-0D62AE2E19B7.jpeg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1157" data-original-width="1472" height="504" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEji__YHQjcZV_FRL1ZT1T2pl-qFg1v8VFdRakHQSDrvKbiULFTHv2sZHqjei8ywiXE6WVTLBbaGq0_Vv3EzXyBndHeECj4QfqYepZg-5VKIX9zj2zxr1LJho4Q-RcmVFibd44PjmleCp-bhvsnsMra6SRPZaDCDm5mm9PSRDUVYbjpoMPhtutGF0GDX0lU/w640-h504/15795F8B-4C87-4664-8B18-0D62AE2E19B7.jpeg" width="640" /></a></div><br /><div style="text-align: left;"> The vacuum Isp of the SSME is <span style="-webkit-text-size-adjust: auto; background-color: #f8f9fa;"><span style="font-family: inherit;">452.3 seconds (4,436 m/s), and the sea level, </span></span><span style="-webkit-text-size-adjust: auto; background-color: #f8f9fa;"><span style="font-family: inherit;">366 seconds (3,590 m/s). You see from the graphic with altitude compensation the Vulcain sea level Isp would be ca. 3,850 m/s. And already at ca. 20,000 m, its altitude compensating Isp would match that of the SSME. An thereafter the the Isp would exceed the maximum vacuum Isp of the SSME. Indeed its Isp could reach 4,850 m/s, and above</span></span></div><div style="text-align: left;"><span style="-webkit-text-size-adjust: auto; background-color: #f8f9fa;"><span style="font-family: inherit;"><br /></span></span></div><div style="text-align: left;"><span style="-webkit-text-size-adjust: auto; background-color: #f8f9fa;"><span style="font-family: inherit;">That the Isp with adaptive nozzles can be this high is supported by calculations for hydrogen/oxygen engines at ultra large expansion ratios. This report concludes at a 600 to 1 expansion ratio we can get ca. 480 s vacuum Isp:</span></span></div><div style="text-align: left;"><span style="-webkit-text-size-adjust: auto; background-color: #f8f9fa;"><span style="font-family: inherit;"><br /></span></span></div><div style="text-align: left;"><div><span class="s1"><span style="font-family: inherit;">ORBITAL TRANSFER VEHICLE (OTV) ENGINE STUDY, PHASE A - EXTENSION<br /></span></span><span class="s1"><span style="font-family: inherit;">CONTRACT NO. NAS8-32996</span></span><span style="font-family: inherit;"><br /></span><span class="s1"><span style="font-family: inherit;"><br /></span></span></div><div><span class="s1"><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi9qldceKNkkDednC-oOyJZVVO6QFVKV8zdzpNjvgzHUo_xn2bvBWv2J1s0XWPtkCa1X9TIsd_jAjEC_L8QXWvI7rf2JkC-5u03sxb2a0K5tUT3Symaz4fTvVz3MrtjaWCpyJRDPBIRj26j-vJ5j_exQjVj86PNDC_CDnstZURmD5JzfRrmBxqlx2Yv-90/s1157/8F3B3AF6-845A-49A2-A375-9B4FE4BCA499.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1007" data-original-width="1157" height="349" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi9qldceKNkkDednC-oOyJZVVO6QFVKV8zdzpNjvgzHUo_xn2bvBWv2J1s0XWPtkCa1X9TIsd_jAjEC_L8QXWvI7rf2JkC-5u03sxb2a0K5tUT3Symaz4fTvVz3MrtjaWCpyJRDPBIRj26j-vJ5j_exQjVj86PNDC_CDnstZURmD5JzfRrmBxqlx2Yv-90/w400-h349/8F3B3AF6-845A-49A2-A375-9B4FE4BCA499.png" width="400" /></a></div><br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjKEWuPBGV62rnPMZjZqTPiRZjUZCNHuWrIFqy6yaidJ-zv15WhZE8ngDQOB-9OowSRNS56sU7N4Qee6Det526QQ1apB2I0wi1mE2vedreqjMVnnGaXFo6_iOYZpfqaX77MTwG0nDf62FRTpIxYPqjZKaHPO3XU0pTjA07rqVy68VqBIgX5dyCUR3u1o38/s732/290BDEB3-A8DA-4BC6-B744-41CE903726EB.jpeg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="501" data-original-width="732" height="274" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjKEWuPBGV62rnPMZjZqTPiRZjUZCNHuWrIFqy6yaidJ-zv15WhZE8ngDQOB-9OowSRNS56sU7N4Qee6Det526QQ1apB2I0wi1mE2vedreqjMVnnGaXFo6_iOYZpfqaX77MTwG0nDf62FRTpIxYPqjZKaHPO3XU0pTjA07rqVy68VqBIgX5dyCUR3u1o38/w400-h274/290BDEB3-A8DA-4BC6-B744-41CE903726EB.jpeg" width="400" /></a></div><br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiDkZqMkbZ61uLtZktI5U9gtAlkextPwLseJ3gTHIant_ZxQ1inAOOrJNCoK39rUTzi2ndFnWZknbOpXWuSqKuQNdXMZ7haWezL5S5IKNnp2HrEyTFz3omSFR8DvA1BzbNU6BCcPWQ1gsxil6ouEDtBICgB616a4rTHT-sB1za34LeoDD_W9P8GL-uo3wk/s1399/E13608BA-F4A6-48E7-8BBC-32E7966D76BD.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="942" data-original-width="1399" height="269" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiDkZqMkbZ61uLtZktI5U9gtAlkextPwLseJ3gTHIant_ZxQ1inAOOrJNCoK39rUTzi2ndFnWZknbOpXWuSqKuQNdXMZ7haWezL5S5IKNnp2HrEyTFz3omSFR8DvA1BzbNU6BCcPWQ1gsxil6ouEDtBICgB616a4rTHT-sB1za34LeoDD_W9P8GL-uo3wk/w400-h269/E13608BA-F4A6-48E7-8BBC-32E7966D76BD.png" width="400" /></a></div></span></div><div><span class="s1"><span style="font-family: inherit;"><br /></span></span></div><div><span class="s1"><span style="font-family: inherit;"><a href="https://ntrs.nasa.gov/api/citations/19800015867/downloads/19800015867.pdf">https://ntrs.nasa.gov/api/citations/19800015867/downloads/19800015867.pdf</a></span></span></div><div><span class="s1"><br /></span></div><div><span class="s1"> The method to get the altitude compensation does not have to be the aerospike nozzle. Better actually would be to add an altitude compensation nozzle extension to an existing engine such as the Vulcain or RS-68. Redesigning such an engine to use an annular combustion chamber for an aerospike nozzle would be expensive. Far cheaper would be to use an altitude compensating nozzle attachment to the already existing engine.</span></div><div><span class="s1"> </span></div><div><span class="s1">Such nozzle extensions already have been in existence for decades on <i>upper stage</i> engines, such as the extendable nozzles on for example the RL-10B2 engine. </span></div><div><span class="s1"><br /></span></div><div><span class="s1"> But in actually the increase in efficiency would be higher for a first stage engine. For instance the vacuum Isp for the Vulcain or RS-68 could be increased from 432s or 412s to 480+ s and above.</span></div><p class="p2" style="-webkit-text-size-adjust: auto; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px;"> <span style="font-family: inherit;"><span class="s1"><a href="https://ntrs.nasa.gov/api/citations/19800015867/downloads/19800015867.pdf"></a></span></span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px;"> The nozzle extension is just a well-known, simple way to accomplish it but there may be simpler or more lightweight methods of accomplishing it. </p><p style="text-align: left;"><span class="s1"><span style="font-family: inherit;">Aerospike in 3D exhaust injection. UPDATED, 1/10/2023: Extension to single nozzles.<br /></span></span><span class="s1"><a href="https://exoscientist.blogspot.com/2023/01/aerospike-in-3d-exhaust-injection.html"><span style="font-family: inherit;">https://exoscientist.blogspot.com/2023/01/aerospike-in-3d-exhaust-injection.html</span></a></span><span class="s1"><span style="font-family: inherit;"><br /></span></span></p><p style="text-align: left;"><span class="s1"><span style="font-family: inherit;">SSME based SSTO’s. UPDATED, 6/28/2021 - Extension to the Delta IV Heavy.<br /></span></span><span class="s1"><a href="https://exoscientist.blogspot.com/2021/06/ssme-based-sstos.html"><span style="font-family: inherit;">https://exoscientist.blogspot.com/2021/06/ssme-based-sstos.html</span></a></span><span class="s1"><span style="font-family: inherit;"><br /></span></span></p><p style="text-align: left;"><span class="s1"><span style="font-family: inherit;">ESA's Callisto reusability testbed as an *operational* TSTO and SSTO. UPDATE, 7/1/2019.<br /></span></span><span class="s1"><a href="https://exoscientist.blogspot.com/2019/05/esas-callisto-reusability-testbed-as.html"><span style="font-family: inherit;">https://exoscientist.blogspot.com/2019/05/esas-callisto-reusability-testbed-as.html</span></a></span><span class="s1"><span style="font-family: inherit;"><br /></span></span></p><p style="text-align: left;"><span class="s1"><span style="font-family: inherit;">Altitude compensation attachments for standard rocket engines, and applications, Page 6: space shuttle tiles and other ceramics for nozzles. UPDATED: 3/6/2018<br /></span></span><span class="s1"><a href="https://exoscientist.blogspot.com/2017/12/altitude-compensation-attachments-for.html"><span style="font-family: inherit;">https://exoscientist.blogspot.com/2017/12/altitude-compensation-attachments-for.html</span></a></span><span class="s1"><span style="font-family: inherit;"><br /></span></span></p><p style="text-align: left;"><span class="s1"><span style="font-family: inherit;">Altitude compensation attachments for standard rocket engines, and applications, Page 5: metal foil expandable nozzles.<br /></span></span><span class="s1"><a href="https://exoscientist.blogspot.com/2017/08/altitude-compensation-attachments-for.html"><span style="font-family: inherit;">https://exoscientist.blogspot.com/2017/08/altitude-compensation-attachments-for.html</span></a></span><span class="s1"><span style="font-family: inherit;"><br /></span></span></p><p style="text-align: left;"><span class="s1"><span style="font-family: inherit;">Altitude compensation attachments for standard rocket engines, and applications, Page 4: the double aerospike.<br /></span></span><span class="s1"><span style="font-family: inherit;"><a href="https://exoscientist.blogspot.com/2016/10/altitude-compensation-attachments-for.html">https://exoscientist.blogspot.com/2016/10/altitude-compensation-attachments-for.html</a></span></span></p><div style="text-align: left;"><span class="s1"><span style="font-family: inherit;">Altitude compensation attachments for standard rocket engines, and applications, Page 3: stretchable metal nozzles.<br /></span></span><a href="https://exoscientist.blogspot.com/2016/06/altitude-compensation-attachments-for.html"><span style="font-family: inherit;">https://exoscientist.blogspot.com/2016/06/altitude-compensation-attachments-for.html</span></a></div><p style="text-align: left;"><span class="s1"><span style="font-family: inherit;">Altitude compensation attachments for standard rocket engines, and applications, Page 2: impulse pressurization methods.<br /></span></span><span class="s1"><a href="https://exoscientist.blogspot.com/2016/01/altitude-compensation-attachments-for.html"><span style="font-family: inherit;">https://exoscientist.blogspot.com/2016/01/altitude-compensation-attachments-for.html</span></a></span><span class="s1"><span style="font-family: inherit;"><br /></span></span></p><p style="text-align: left;"><span class="s1"><span style="font-family: inherit;">Altitude compensation attachments for standard rocket engines, and applications.<br /></span></span><span class="s1"><a href="https://exoscientist.blogspot.com/2014/10/altitude-compensation-attachments-for.html"><span style="font-family: inherit;">https://exoscientist.blogspot.com/2014/10/altitude-compensation-attachments-for.html</span></a></span><span class="s1"><span style="font-family: inherit;"><br /></span></span></p><p style="text-align: left;"><span class="s1"><span style="font-family: inherit;">The Coming SSTO's.<br /></span></span><span class="s1"><span style="font-family: inherit;"><a href="https://exoscientist.blogspot.com/2012/05/coming-sstos.html">https://exoscientist.blogspot.com/2012/05/coming-sstos.html</a></span></span></p><div style="text-align: left;"><span class="s1"><span style="font-family: inherit;">Altitude Compensation Improves Payload for All Launchers.<br /></span></span><a href="https://exoscientist.blogspot.com/2016/01/altitude-compensation-improves-payload.html"><span style="font-family: inherit;">https://exoscientist.blogspot.com/2016/01/altitude-compensation-improves-payload.html</span></a></div><p style="text-align: left;"><span style="-webkit-text-size-adjust: auto; background-color: #f8f9fa;"> </span></p><p style="text-align: left;"><span style="-webkit-text-size-adjust: auto; background-color: #f8f9fa;"> Robert Clark</span></p><p class="p1" style="-webkit-text-size-adjust: auto; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-align: left;"><span style="font-family: inherit;"><span class="s1"></span></span></p><p class="p1" style="-webkit-text-size-adjust: auto; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-align: left;"><span style="font-family: inherit;"><span class="s1"></span></span></p><p class="p1" style="-webkit-text-size-adjust: auto; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-align: left;"><span style="font-family: inherit;"><span class="s1"></span></span></p><p class="p1" style="-webkit-text-size-adjust: auto; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-align: left;"><span style="font-family: inherit;"><span class="s1"></span></span></p><p class="p1" style="-webkit-text-size-adjust: auto; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-align: left;"><span style="font-family: inherit;"><span class="s1"></span></span></p><p class="p1" style="-webkit-text-size-adjust: auto; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-align: left;"><span style="font-family: inherit;"><span class="s1"></span></span></p><p class="p1" style="-webkit-text-size-adjust: auto; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-align: left;"><span style="font-family: inherit;"><span class="s1"></span></span></p><p class="p1" style="-webkit-text-size-adjust: auto; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-align: left;"><span style="font-family: inherit;"><span class="s1"></span></span></p><p class="p1" style="-webkit-text-size-adjust: auto; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-align: left;"><span style="font-family: inherit;"><span class="s1"></span></span></p><p class="p1" style="-webkit-text-size-adjust: auto; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-align: left;"><span style="font-family: inherit;"><span class="s1"></span></span></p><p class="p1" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-align: left;"><span class="s1" style="font-family: UICTFontTextStyleBody;"></span><br /></p></div><div style="text-align: left;"><span style="-webkit-text-size-adjust: auto; background-color: #f8f9fa;"><span style="font-family: inherit;"><br /></span></span></div>Robert Clarkhttp://www.blogger.com/profile/16114043697010364282noreply@blogger.com9tag:blogger.com,1999:blog-7598615455712402973.post-3334178122574092062024-02-22T13:21:00.004-05:002024-02-26T15:37:32.927-05:00Could meteor impacts be the cause of the coronal heating problem?<p style="text-align: center;"><i> Copyright 2024 Robert Clark</i></p><p style="text-align: center;"><i><br /></i></p><p style="text-align: left;"><i> </i>A puzzle in solar science that has existed for 150 years is the corona heating problem:</p><p>Why is the sun’s corona 200 times hotter than its surface?<br />The paradox has astronomers scratching their heads over magnetic waves, nanoflares, and the now-debunked element coronium.<br />BY BRILEY LEWIS | PUBLISHED APR 12, 2023 6:00 AM EDT<br /><a href="https://www.popsci.com/science/how-hot-is-the-suns-surface-corona/">https://www.popsci.com/science/how-hot-is-the-suns-surface-corona/</a></p><p> The Sun's surface is at about 10,000 F, 5,500 C. But the solar corona reaches millions of degrees. How is it possible to get so much hotter hundreds of thousands kilometers away from the Suns surface?</p><p> Noted solar astronomer Eugene Parker for whom the Parker Solar probe was named suggested it was due to nanoflares small flares emanating from the solar surface much smaller than the usual solar flares:</p><p style="text-align: center;">ScienceCasts: The Mystery of Nanoflares.</p><div class="separator" style="clear: both; text-align: center;"><iframe allowfullscreen="" class="BLOG_video_class" height="266" src="https://www.youtube.com/embed/wjB9JtTU7SU" width="320" youtube-src-id="wjB9JtTU7SU"></iframe></div><p> But what causes the nanoflares? Could it be asteroidal impacts? The argument could be made they are too small to cause any visible reaction on the Sun. But the question is of the local impact. The Sun’s escape velocity at its surface is 600 km/s. That is a tremendous amount of energy for a body impacting it at that speed. When material is thrown up after the impact the high temperature could be maintained far above the surface.</p><p>Nanoflares and coronal heating.</p><div class="separator" style="clear: both; text-align: center;"><a href="https://est-east.eu/images/TheScienceOfEST/image/EST_Nanoflares_Helle_Bakke.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="776" data-original-width="800" height="776" src="https://est-east.eu/images/TheScienceOfEST/image/EST_Nanoflares_Helle_Bakke.jpg" width="800" /></a></div><p style="text-align: center;"> <span style="-webkit-tap-highlight-color: rgba(0, 0, 0, 0); -webkit-text-size-adjust: 100%; background-color: white; caret-color: rgb(33, 37, 41); color: #212529; font-family: arial, helvetica, sans-serif; font-size: 10.666667px; text-align: -webkit-center;">Micro-flare observed on 4 September 2016 with NASA SDO/AIA and the Swedish 1-m Solar Telescope.</span></p><p><span style="-webkit-tap-highlight-color: rgba(0, 0, 0, 0); -webkit-text-size-adjust: 100%; background-color: white; caret-color: rgb(33, 37, 41); color: #212529; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji"; font-size: 16px;"><i>The image shows a micro-flare observed on 4 September 2016. Magnetic reconnection in the corona as sketched in the cartoon in the lower left produces a hot loop of more than 7 million degrees. This hot loop is visible as the bright area in the green background image taken with the Solar Dynamics Observatory (AIA 94 Å). The active region with bright magnetic loops is shown in more detail in the yellow inset, corresponding to plasma of less than 1 million degrees (AIA 171 Å). The reconnection event in the corona produces fast electrons that hit the lower atmosphere with high energy. The impact region is very small and is shown at high resolution in the image taken with the Swedish 1-m Solar Telescope on La Palma. With the European Solar Telescope, we will be able to study the magnetic environment of the impact region in even finer detail.</i></span></p><p><a href="https://est-east.eu/?option=com_content&view=article&id=920&Itemid=622&lang=en">https://est-east.eu/?option=com_content&view=article&id=920&Itemid=622&lang=en</a></p><p> For instance Jupiter’s escape velocity is 60 km/s and we saw the tremendous resulting impact from comet Shoemaker-Levy when it impacted Jupiter.</p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgQUAuqaqtdy-AUvC3ntFHh9BVpmuVskwEQr1K1POvFxPswBo3WOdz1wkpn7T1qWStf0FxqmCIF2yZkaFYvFvcqzgERp_KBkmEVYs8TWtF_W01cj75Kz3Xqh1N90B0jGvJhNFEUnqPZew6k3wv7bhGpj5U0Byi1KpD3ey-RqpU5P9T-7oTzLZJ-17zVQkw/s480/183B1433-F0C0-4F4F-B812-4A64453B5871.gif" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="360" data-original-width="480" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgQUAuqaqtdy-AUvC3ntFHh9BVpmuVskwEQr1K1POvFxPswBo3WOdz1wkpn7T1qWStf0FxqmCIF2yZkaFYvFvcqzgERp_KBkmEVYs8TWtF_W01cj75Kz3Xqh1N90B0jGvJhNFEUnqPZew6k3wv7bhGpj5U0Byi1KpD3ey-RqpU5P9T-7oTzLZJ-17zVQkw/w640-h480/183B1433-F0C0-4F4F-B812-4A64453B5871.gif" width="640" /></a></div><p><span style="-webkit-text-size-adjust: 100%; background-color: #63007f; caret-color: rgb(147, 147, 147); font-family: Alegreya, serif; font-size: 14.25px; font-style: italic; text-align: center;"><span style="color: white;">Jupiter in infrared, Shoemaker-Levy 9 collision (left) and Io (right) by </span></span><a href="http://nssdc.gsfc.nasa.gov/planetary/sl9/comet_images.html" style="-webkit-text-size-adjust: 100%; color: #0087be; font-family: Alegreya, serif; font-size: 14.25px; font-style: italic; text-align: center; text-decoration: none;">Max Planck Institute for Astronomy</a> </p><p> But the major, key reason for suspecting it is this: there is a type of nuclear fusion called impact fusion. It arises when bodies are made to collide at hundreds of kilometers per second relative impact speed. </p><div style="text-align: left;">Proceedings of the<br />Impact Fusion Workshop ~ National Security and Resources Study Center<br />LOS Alamos Scientific Laboratory Los Alamos, New Mexico<br />LOSALAMOS SCIENTI<br />LABORATORY<br />PostOfficeBox 1663 LosAlamos,New Mexico87545<br />July 10—12, 1979</div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjRPSdck9oyzrEmrL-o36dmD7YG_UO9AxMBfzlzLRi05zj8hAoyYd8W8VEmFfCdp14BptwWed3Zkw1Tz50pjfYC0yCO5Zx3N4i_PToRKeQDhkFvH_BuNxLFnkkT834rIvu_CXQG0-Ll-z-bAfNPebUc2ttUjhpT_uxdOK3WUmaVlxkF8eA42-Vg9dlGIbk/s2160/C6F87D32-B1AF-40E5-B53F-C40BFF0003FA.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="2160" data-original-width="1620" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjRPSdck9oyzrEmrL-o36dmD7YG_UO9AxMBfzlzLRi05zj8hAoyYd8W8VEmFfCdp14BptwWed3Zkw1Tz50pjfYC0yCO5Zx3N4i_PToRKeQDhkFvH_BuNxLFnkkT834rIvu_CXQG0-Ll-z-bAfNPebUc2ttUjhpT_uxdOK3WUmaVlxkF8eA42-Vg9dlGIbk/w480-h640/C6F87D32-B1AF-40E5-B53F-C40BFF0003FA.png" width="480" /></a></div><div style="text-align: left;"><br /></div><div style="text-align: center;"><a href="https://sgp.fas.org/othergov/doe/lanl/lib-www/la-pubs/00203259.pdf">https://sgp.fas.org/othergov/doe/lanl/lib-www/la-pubs/00203259.pdf</a></div><p style="text-align: left;">There are private fusion research concerns now investigating this to bring about controlled nuclear fusion. </p><p> Recent observations of nanoflares have observed million degree temperatures locally around the nanoflares origin point on the Sun’s surface, while the surrounding area is at the normal 5,500 C temperature.</p><p> So why don’t we see the asteroids during imaging of the nanoflares? It could be their small size. The Sun is so bright it completely washes out the asteroids that may be only a few kilometers across.</p><p>Recent observations and theoretical modeling suggest the million degree temperatures seen in the vicinity of the nanoflare origin point on the Sun’s surface should be able to be communicated to the corona-sphere thousands of kilometers above the Suns surface:</p><div style="text-align: left;">This May Be the First Complete Observation of a Nanoflare.<br />Heating the corona.<br /><i>So far, these bright loops appeared to be tiny flares – but did their heat actually reach the corona?Bahauddin looked to NASA’s Solar Dynamics Observatory, which carries telescopes tuned to see the extremely hot plasma only found in the corona. Bahauddin located the regions right above the brightenings shortly after they appeared. “And there it was, just a 20-second delay,” Bahauddin said. “We saw the brightening, and then we suddenly saw the corona got super-heated to multi-million degree temperatures,” Bahauddin said. “SDO gave us this important information: Yes, this is indeed increasing the temperature, transferring energy to the corona.” Bahauddin documented 10 instances of bright loops with similar effects on the corona. Still, he hesitates to call them nanoflares. “Nobody actually knows because nobody has seen it before,” Bahauddin said. “It’s an educated guess, let’s say.”From the perspective of the theory that says nanoflares heat the corona, the only thing left to do is to show that these brightenings occur often enough, all over the Sun, to account for the corona’s extreme heat. That’s still work in progress. But observing these tiny bursts as they heat solar atmosphere is a compelling start.<br /></i><a href="https://www.nasa.gov/solar-system/this-may-be-the-first-complete-observation-of-a-nanoflare/">https://www.nasa.gov/solar-system/this-may-be-the-first-complete-observation-of-a-nanoflare/</a></div><p style="text-align: left;">Additionally I was startled see to what would be the kinetic energy of an asteroid impacting the Sun at the 600 km/s escape velocity. Asteroids have been estimated to have densities in the range of 2,000 kg/m3 to 5,000 kg/m3 . The iron-nickel asteroids would have the higher density. This is important because they could also maintain their cohesiveness as they impacted the Sun.</p><p>Searches of a population of asteroids inside the orbit of Mercury, called vulcanoids, have been unsuccessful. This is because you have to look at the bright solar disk to detect them. But such searches put a size limit of 6 km wide on them. So assume the asteroid has size, say, 5 km across, with density, say, 4,000 kg/m3 . At that density the mass would be 4,000 kg/m^3 * (6,000 m)^3 = 8.64 * 10^14 kg. Now suppose this impacted the Sun at 600 km/s. Then the kinetic energy of that pact would be:</p><p>(1/2) * 8.64 * 10^14 * (600,000 m)^2 = 1.55*10^26 Joules. That is a tremendous amount of energy! To put in perspective the energy the Sun puts out each second is 3.86 * 10^26 watts. So if the asteroid deposited that energy in, say, 1 second, it would be a significant percentage of the total energy the Sun puts out in a second!</p><p> However, asteroids of kilometers size impacting the Sun must be quite rare, judging from this graph of asteroid impacts to Earth by size:</p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi9IULJ3s4W6dxN0OBt2jzF5ssyr7zwjDooo8MHPbOlv5CP-U7KsOt68jTVonowi-WbODBtNNnXGNCfkVHc4Zjh3U7f4BCR6kh3_-f4hcRP5RsmNaExiSSp64L4yEWQj3IEGOQnc-ZCG-KZBV5bIcmRcWXGiIz7gtYzpe0cwcsFvbhzNvqwl1ye-RDFztQ/s438/E6E3DBF8-2547-4E21-B3F9-E00E2D91672F.gif" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="402" data-original-width="438" height="588" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi9IULJ3s4W6dxN0OBt2jzF5ssyr7zwjDooo8MHPbOlv5CP-U7KsOt68jTVonowi-WbODBtNNnXGNCfkVHc4Zjh3U7f4BCR6kh3_-f4hcRP5RsmNaExiSSp64L4yEWQj3IEGOQnc-ZCG-KZBV5bIcmRcWXGiIz7gtYzpe0cwcsFvbhzNvqwl1ye-RDFztQ/w640-h588/E6E3DBF8-2547-4E21-B3F9-E00E2D91672F.gif" width="640" /></a></div><div style="text-align: center;"><a href="https://www2.tulane.edu/~sanelson/Natural_Disasters/impacts.htm">https://www2.tulane.edu/~sanelson/Natural_Disasters/impacts.htm</a></div><div style="text-align: center;"><br /></div><div style="text-align: left;"> One meter and below must be more common. If the meteor impacting the Sun was 1 meter wide, then the kinetic energy would be (1/2)*4,000*(1)^3*(600000)^2 = 7.2*10^14 joules, nearly a quadrillion joules of energy.</div><p> About the likelihood of asteroids impacting the Sun in accordance to the change needed in their established orbital velocity, if they started further out in the Solar System, much less velocity change (delta-v) would be needed to direct them to impact the Sun.</p><p> Key confirmation required is to confirm the existence of these small solar impactors. Observations in the visual light spectrum have not succeeded. This is the solar irradiance spectrum showing the range of intensity’s according to wavelength:</p><div class="separator" style="clear: both; text-align: center;"><a href="https://www.ncei.noaa.gov/sites/default/files/styles/wide_full_width_image_no_crop/public/2020-12/Solar%20Spectral%20Irradiance.png?itok=4YvmwX-L" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="800" data-original-width="747" height="800" src="https://www.ncei.noaa.gov/sites/default/files/styles/wide_full_width_image_no_crop/public/2020-12/Solar%20Spectral%20Irradiance.png?itok=4YvmwX-L" width="747" /></a></div><br /><p><br /></p><p><br /></p><p> You see it is vanishingly small at extreme ultraviolet wavelengths and at radio wavelengths around 10,000 nm, 10 microns, and above. The problem with observations at the extreme ultraviolet is that not large enough telescopes have been launched to observe them at less than 6 km diameters (the extreme UV is absorbed by the Earth’s atmosphere.)</p><p> Then the suggestion is to use large radio telescopes at the micron and above wavelengths to detect the close in asteroids.</p><p> One radio telescope that might manage it is the ALMA radio telescope array:</p><div style="text-align: left;"><span class="s1"><h1 class="news-hgroup__heading" style="-webkit-text-size-adjust: 100%; border: 0px; color: #373737; font-stretch: inherit; line-height: 1.1; margin: 0px 0px 20px; padding: 0px; vertical-align: baseline;"><span style="font-family: inherit; font-size: small;">ALMA Demonstrates Highest Resolution Yet</span></h1><h1 class="news-hgroup__heading" style="-webkit-text-size-adjust: 100%; border: 0px; color: #373737; font-stretch: inherit; line-height: 1.1; margin: 0px 0px 20px; padding: 0px; vertical-align: baseline;"><span style="font-family: inherit; font-size: small;"><time datetime="2023-11-15" style="border: 0px; font-stretch: inherit; font-style: inherit; font-variant-caps: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;">November 15, 2023 </time>| <a href="https://www.nao.ac.jp/en/news/science/" style="border: 0px; color: #743f83; font-stretch: inherit; font-style: inherit; font-variant-caps: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;">Science</a></span></h1></span><span class="s1"><span style="font-family: inherit;"><span style="font-family: inherit;">T</span>he Band-to-band (B2B) method demonstrated this time to achieve the highest resolution with ALMA. In the B2B method, atmospheric fluctuations are compensated for by observing a nearby calibrator in low frequency radio waves, while the target is observed with high frequency radio waves. The top right inset image shows the ALMA image of R Leporis that achieved the highest resolution of 5 milli-arcsec. Submillimeter-wave emissions from the stellar surface are shown in orange and hydrogen cyanide maser emissions at 891 GHz are shown in blue. The top left inset image shows a previous observation of the same star using a different array configuration with less distance between the antennas and without the B2B method, resulting in a resolution of 75 milli-arcsec. The previous resolution is too coarse to specify the positions of each of the two emission components. (Credit: ALMA (ESO/NAOJ/NRAO), Y. Asaki et al.) <span class="s2"><a href="https://www.nao.ac.jp/en/contents/news/science/2023/20231115-alma-fig-full.jpg">Download image (1.3MB)</a></span></span></span></div><div style="text-align: left;"><br /></div><div style="text-align: left;"><span class="s1"><a href="https://www.nao.ac.jp/en/news/science/2023/20231115-alma.html#:~:text=The%20team%20succeeded%20in%20observing,and%20a%20half%20miles%20away.">https://www.nao.ac.jp/en/news/science/2023/20231115-alma.html</a></span></div><div style="text-align: left;"><br /></div><div style="text-align: left;"> At a max resolution of 5 milli-arc it should be able to detect kilometer wide asteroids at the distance of the Sun. The detection sensitivity should also be improved for iron-nickel meteorites for radio astronomy.</div><p> Note the importance of this is that if it is confirmed then we know impact fusion does indeed work.</p><p> Bob Clark</p><p><br /></p>Robert Clarkhttp://www.blogger.com/profile/16114043697010364282noreply@blogger.com1tag:blogger.com,1999:blog-7598615455712402973.post-35297780640405383142024-02-08T16:02:00.001-05:002024-02-09T01:43:05.717-05:00Alternative explanations for the CMB, universe expansion, and dark matter. <p style="text-align: center;"> <i>Copyright 2024 Robert Clark</i></p><p style="text-align: center;"><i><br /></i></p><p style="text-align: left;"> James Webb was promised to provide revolutionary results in cosmology and has not disappointed. Several observations have shown well-developed galaxies that stem from the earliest time after the Big Bang, which current theories suggest should not be possible. </p><h2 class="slim-video-information-title slim-video-metadata-title-modern" style="-webkit-box-orient: vertical; -webkit-text-size-adjust: 100%; caret-color: rgb(241, 241, 241); display: -webkit-box; font-weight: 500; line-height: 2.6rem; margin: 0px 0px 3px; max-height: none; overflow: hidden; text-align: center; text-overflow: ellipsis;"><span class="yt-core-attributed-string" role="text"><span style="font-family: inherit; font-size: small;">JWST finds very early galaxies that should not exist.</span></span></h2><p style="text-align: left;"></p><div class="separator" style="clear: both; text-align: center;"><iframe allowfullscreen="" class="BLOG_video_class" height="266" src="https://www.youtube.com/embed/pY_iZjfqdIc" width="320" youtube-src-id="pY_iZjfqdIc"></iframe></div><p style="text-align: left;"> The observations have led some scientists to question the accuracy of the current models for the beginning of the universe. Further, the cosmological microwave background(CMB) had been regarded as strong confirmation of the Big Bang theory for the origin of the universe. But there is a discrepancy between the rate of expansion of the universe based on the CMB and measurements of galactic motion.</p><p style="text-align: left;"> This discrepancy has existed for several years now, but it was hoped with better instruments the discrepancy would be found due to measurement error. Instead, the JWST has provided further evidence the discrepancy is real. Then either the CMB estimate or the interpretation of the redshift measurements or both are wrong.</p><p style="text-align: left;"></p><div class="separator" style="clear: both; text-align: center;"><iframe allowfullscreen="" class="BLOG_video_class" height="266" src="https://www.youtube.com/embed/Jam61H0SA3Q" width="320" youtube-src-id="Jam61H0SA3Q"></iframe></div><br /><p></p><p style="text-align: left;"> Here I'll discuss the possibility there is a problem with the interpretation of the origin of the CMB.<span style="font-family: inherit;"> <span style="background-color: white; color: #1c1c1c;">It seems to me there should be some contribution to the CMB due to highly red shifted infrared and optical radiation from galaxies at high red shifts, but I never see this mentioned. The CMB is only described by relic radiation of the intense heat at the beginning of time that gradually cooled as the universe expanded.</span></span></p><p style="text-align: left;"><span style="font-family: inherit;"><span style="background-color: white; color: #1c1c1c;"> An argument can be made that the CMB is seen in all directions but there are blank areas in some part of the sky. This does not support the idea of the CMB deriving from redshifted light from primordial galaxies. </span></span></p><p style="text-align: left;"><span style="font-family: inherit;"><span style="background-color: white; color: #1c1c1c;"> But the Hubble Deep Field showed abundant galaxies in areas previous thought to be devoid of galaxies.<span style="font-family: inherit;"> </span></span></span><span style="background-color: white; color: #1c1c1c;"><span style="font-family: inherit;">It was a revolutionary advance in our knowledge of the extent of the universe. Hubble deep field images integration times ranged from 10 days to 23 days. But the JWST deep field image only went for a day:</span></span></p><p class="_1qeIAgB0cPwnLhDF9XSiJM" style="background-color: white; border: 0px; color: #1c1c1c; font-stretch: inherit; font-variant-east-asian: inherit; font-variant-numeric: inherit; line-height: inherit; margin: 0px; padding: 0.8em 0px 0.25em; vertical-align: baseline;"><span style="font-family: inherit;">STARTS WITH A BANG — APRIL 17, 2023<br />JWST surpasses, enhances Hubble’s deepest image ever<br />With infrared capabilities and image sharpness far beyond Hubble's limits, JWST looked at Hubble's deepest field, revealing so much more.<br /><a class="_3t5uN8xUmg0TOwRCOGQEcU" href="https://bigthink.com/starts-with-a-bang/jwst-surpasses-hubbles-deepest-image/" original_target="https://bigthink.com/starts-with-a-bang/jwst-surpasses-hubbles-deepest-image/" rel="noopener nofollow ugc" style="border: 0px; display: inline-block; font-stretch: inherit; font-style: inherit; font-variant-alternates: inherit; font-variant-caps: inherit; font-variant-east-asian: inherit; font-variant-ligatures: inherit; font-variant-numeric: inherit; font-variant-position: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;" target="_blank" waprocessedanchor="true" waprocessedid="2rvsqj">https://bigthink.com/starts-with-a-bang/jwst-surpasses-hubbles-deepest-image/</a></span></p><p class="_1qeIAgB0cPwnLhDF9XSiJM" style="background-color: white; border: 0px; color: #1c1c1c; font-stretch: inherit; font-variant-east-asian: inherit; font-variant-numeric: inherit; line-height: inherit; margin: 0px; padding: 0.8em 0px 0.25em; vertical-align: baseline;"><span style="font-family: inherit;">In view of the startling find of fully formed galaxies going back to near the time of the Big Bang by the JWST, such long integration times as for the Hubble must also be done for the JWST.</span></p><p class="_1qeIAgB0cPwnLhDF9XSiJM" style="background-color: white; border: 0px; color: #1c1c1c; font-stretch: inherit; font-variant-east-asian: inherit; font-variant-numeric: inherit; line-height: inherit; margin: 0px; padding: 0.8em 0px 0.25em; vertical-align: baseline;"><span style="font-family: inherit;">The estimate of the number of galaxies in the universe from the Hubble deep field was 170 billion. But numerical simulations put it at perhaps one hundred times more at 6 to 20 trillion galaxies:</span></p><p class="_1qeIAgB0cPwnLhDF9XSiJM" style="background-color: white; border: 0px; color: #1c1c1c; font-stretch: inherit; font-variant-east-asian: inherit; font-variant-numeric: inherit; line-height: inherit; margin: 0px; padding: 0.8em 0px 0.25em; vertical-align: baseline;"><span style="font-family: inherit;">STARTS WITH A BANG — JUNE 22, 2022<br />There are more galaxies in the Universe than even Carl Sagan ever imagined<br />Forget billions and billions. When it comes to the number of galaxies in the Universe, both theorists' and observers' estimates are too low.<br /><a class="_3t5uN8xUmg0TOwRCOGQEcU" href="https://bigthink.com/starts-with-a-bang/galaxies-in-universe/" original_target="https://bigthink.com/starts-with-a-bang/galaxies-in-universe/" rel="noopener nofollow ugc" style="border: 0px; display: inline-block; font-stretch: inherit; font-style: inherit; font-variant-alternates: inherit; font-variant-caps: inherit; font-variant-east-asian: inherit; font-variant-ligatures: inherit; font-variant-numeric: inherit; font-variant-position: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;" target="_blank" waprocessedanchor="true" waprocessedid="ajth6l">https://bigthink.com/starts-with-a-bang/galaxies-in-universe/</a></span></p><p class="_1qeIAgB0cPwnLhDF9XSiJM" style="background-color: white; border: 0px; color: #1c1c1c; font-stretch: inherit; font-variant-east-asian: inherit; font-variant-numeric: inherit; line-height: inherit; margin: 0px; padding: 0.8em 0px 0px; vertical-align: baseline;"><span style="font-family: inherit;">By doing the longer integration times JWST may be able to confirm this larger number of galaxies. Such a large number of galaxies going back to near the time of the Big Bang may allow the CMB to be equally well explained by highly redshifted light, infrared and optical, from these earliest galaxies.</span></p><p class="_1qeIAgB0cPwnLhDF9XSiJM" style="background-color: white; border: 0px; color: #1c1c1c; font-stretch: inherit; font-variant-east-asian: inherit; font-variant-numeric: inherit; line-height: inherit; margin: 0px; padding: 0.8em 0px 0px; vertical-align: baseline;"><span style="font-family: inherit;"> However, there may be another even greater contributor to the observed CMB. A little known fact is that for most of the galaxies in the universe they are receding from us faster than the speed of light(!)</span></p><p class="_1qeIAgB0cPwnLhDF9XSiJM" style="background-color: white; border: 0px; color: #1c1c1c; font-stretch: inherit; font-variant-east-asian: inherit; font-variant-numeric: inherit; line-height: inherit; margin: 0px; padding: 0.8em 0px 0px; vertical-align: baseline;"><span style="font-family: inherit;"><br /></span></p><h1 class="style-scope ytd-watch-metadata" style="-webkit-box-orient: vertical; -webkit-line-clamp: 2; background-color: white; background: rgb(255, 255, 255); border: 0px; color: #0f0f0f; display: -webkit-box; line-height: 2.8rem; margin: 0px; max-height: 5.6rem; overflow: hidden; padding: 0px; text-align: center; text-overflow: ellipsis; word-break: break-word;"><yt-formatted-string class="style-scope ytd-watch-metadata" force-default-style=""><span style="font-family: inherit; font-size: small; font-weight: normal;">97% of Galaxies Are Moving Faster Than Light, HOW IS THIS POSSIBLE?</span></yt-formatted-string></h1><p style="text-align: left;"><span style="font-family: inherit;"></span></p><div class="separator" style="clear: both; text-align: center;"><span style="font-family: inherit;"><iframe allowfullscreen="" class="BLOG_video_class" height="266" src="https://www.youtube.com/embed/cadNZJvfl7s" width="320" youtube-src-id="cadNZJvfl7s"></iframe></span></div><span style="font-family: inherit;"><br /><span style="background-color: white; color: #1c1c1c;"> This is explained as not being in conflict with relativity by the virtue of the fact that space itself is expanding. It is not the case that objects are moving <i>through</i> space as these superluminal speeds. </span></span><p></p><p style="text-align: left;"><span style="font-family: inherit;"><span style="background-color: white; color: #1c1c1c;"> Nevertheless, this raises an interesting possibility. If it is the case that these galaxies are moving away from us at these <i>apparent</i> superluminal speeds, would we observe a luminal "boom" from these galaxies when they <i>appear</i> to cross the light-speed barrier relative to us? </span></span></p><p style="text-align: left;"><span style="background-color: white;"><span style="color: #1c1c1c; font-family: inherit;"> The luminal boom is a concept that is analogous to the sonic boom for sound waves. This is actually seen for some subatomic particles traveling though matter, where the speed of light is reduced below that of the vacuum speed. In cases where the particles exceed that materials light speed, a phenomenon known as Cerenkov radiation is observed. Note that the particles are still not traveling faster than the </span><i style="color: #1c1c1c; font-family: inherit;">vacuum</i><span style="color: #1c1c1c; font-family: inherit;"> speed of light, only the speed of light in the material. So </span><span style="color: #1c1c1c;">relativity</span><span style="color: #1c1c1c; font-family: inherit;"> is still upheld.</span></span></p><p style="text-align: left;"><span style="background-color: white;"><span style="color: #1c1c1c; font-family: inherit;"> An analogous phenomenon is seen in cosmic ultra high energy gamma ray bursts, GRB's:</span></span></p><p><span style="color: #1c1c1c;">Faster-Than-Light Speeds Could Be Why Gamma-Ray Bursts Seem to Go Backwards in Time.<br /></span><span style="color: #1c1c1c;">SPACE<br /></span><span style="color: #1c1c1c;">30 September 2019<br /></span><span style="color: #1c1c1c;">By MICHELLE STARR</span></p><p><span style="color: #1c1c1c;"><a href="https://www.sciencealert.com/faster-than-light-speed-in-jets-that-produce-gamma-ray-bursts">https://www.sciencealert.com/faster-than-light-speed-in-jets-that-produce-gamma-ray-bursts</a></span></p><p><br /></p><p> This blog post contained the discussion of an alternative explanation for the CMB. Follow up posts will discuss alternative explanations for universe expansion and dark matter.</p><p> Robert Clark</p><div class="flex flex-wrap items-center mb-4" style="--tw-blur: var(--tw-empty, ); --tw-brightness: var(--tw-empty, ); --tw-contrast: var(--tw-empty, ); --tw-drop-shadow: var(--tw-empty, ); --tw-filter: var(--tw-blur) var(--tw-brightness) var(--tw-contrast) var(--tw-grayscale) var(--tw-hue-rotate) var(--tw-invert) var(--tw-saturate) var(--tw-sepia) var(--tw-drop-shadow); --tw-grayscale: var(--tw-empty, ); --tw-hue-rotate: var(--tw-empty, ); --tw-invert: var(--tw-empty, ); --tw-rotate: 0; --tw-saturate: var(--tw-empty, ); --tw-scale-x: 1; --tw-scale-y: 1; --tw-sepia: var(--tw-empty, ); --tw-skew-x: 0; --tw-skew-y: 0; --tw-transform: translateX(var(--tw-translate-x)) translateY(var(--tw-translate-y)) rotate(var(--tw-rotate)) skewX(var(--tw-skew-x)) skewY(var(--tw-skew-y)) scaleX(var(--tw-scale-x)) scaleY(var(--tw-scale-y)); --tw-translate-x: 0; --tw-translate-y: 0; align-items: center; border: 0px solid currentcolor; box-sizing: border-box; color: #333333; display: flex; flex-wrap: wrap; letter-spacing: -0.4px; margin-bottom: 1rem;"><div class="author-details" style="--tw-blur: var(--tw-empty, ); --tw-brightness: var(--tw-empty, ); --tw-contrast: var(--tw-empty, ); --tw-drop-shadow: var(--tw-empty, ); --tw-filter: var(--tw-blur) var(--tw-brightness) var(--tw-contrast) var(--tw-grayscale) var(--tw-hue-rotate) var(--tw-invert) var(--tw-saturate) var(--tw-sepia) var(--tw-drop-shadow); --tw-grayscale: var(--tw-empty, ); --tw-hue-rotate: var(--tw-empty, ); --tw-invert: var(--tw-empty, ); --tw-rotate: 0; --tw-saturate: var(--tw-empty, ); --tw-scale-x: 1; --tw-scale-y: 1; --tw-sepia: var(--tw-empty, ); --tw-skew-x: 0; --tw-skew-y: 0; --tw-transform: translateX(var(--tw-translate-x)) translateY(var(--tw-translate-y)) rotate(var(--tw-rotate)) skewX(var(--tw-skew-x)) skewY(var(--tw-skew-y)) scaleX(var(--tw-scale-x)) scaleY(var(--tw-scale-y)); --tw-translate-x: 0; --tw-translate-y: 0; border: 0px solid currentcolor; box-sizing: border-box; line-height: 19px;"><br /></div><div class="author-details" style="--tw-blur: var(--tw-empty, ); --tw-brightness: var(--tw-empty, ); --tw-contrast: var(--tw-empty, ); --tw-drop-shadow: var(--tw-empty, ); --tw-filter: var(--tw-blur) var(--tw-brightness) var(--tw-contrast) var(--tw-grayscale) var(--tw-hue-rotate) var(--tw-invert) var(--tw-saturate) var(--tw-sepia) var(--tw-drop-shadow); --tw-grayscale: var(--tw-empty, ); --tw-hue-rotate: var(--tw-empty, ); --tw-invert: var(--tw-empty, ); --tw-rotate: 0; --tw-saturate: var(--tw-empty, ); --tw-scale-x: 1; --tw-scale-y: 1; --tw-sepia: var(--tw-empty, ); --tw-skew-x: 0; --tw-skew-y: 0; --tw-transform: translateX(var(--tw-translate-x)) translateY(var(--tw-translate-y)) rotate(var(--tw-rotate)) skewX(var(--tw-skew-x)) skewY(var(--tw-skew-y)) scaleX(var(--tw-scale-x)) scaleY(var(--tw-scale-y)); --tw-translate-x: 0; --tw-translate-y: 0; border: 0px solid currentcolor; box-sizing: border-box; font-family: "Open Sans", Helvetica, Arial, sans-serif; font-size: 16px; line-height: 19px;"><br /></div><div class="author-details" style="--tw-blur: var(--tw-empty, ); --tw-brightness: var(--tw-empty, ); --tw-contrast: var(--tw-empty, ); --tw-drop-shadow: var(--tw-empty, ); --tw-filter: var(--tw-blur) var(--tw-brightness) var(--tw-contrast) var(--tw-grayscale) var(--tw-hue-rotate) var(--tw-invert) var(--tw-saturate) var(--tw-sepia) var(--tw-drop-shadow); --tw-grayscale: var(--tw-empty, ); --tw-hue-rotate: var(--tw-empty, ); --tw-invert: var(--tw-empty, ); --tw-rotate: 0; --tw-saturate: var(--tw-empty, ); --tw-scale-x: 1; --tw-scale-y: 1; --tw-sepia: var(--tw-empty, ); --tw-skew-x: 0; --tw-skew-y: 0; --tw-transform: translateX(var(--tw-translate-x)) translateY(var(--tw-translate-y)) rotate(var(--tw-rotate)) skewX(var(--tw-skew-x)) skewY(var(--tw-skew-y)) scaleX(var(--tw-scale-x)) scaleY(var(--tw-scale-y)); --tw-translate-x: 0; --tw-translate-y: 0; border: 0px solid currentcolor; box-sizing: border-box; font-family: "Open Sans", Helvetica, Arial, sans-serif; font-size: 16px; line-height: 19px;"><br /></div></div><p style="text-align: left;"><span style="background-color: white;"><span style="color: #1c1c1c; font-family: inherit;"> </span></span></p><p style="text-align: left;"><span style="font-family: inherit;"><span style="background-color: white; color: #1c1c1c;"><br /></span></span></p>Robert Clarkhttp://www.blogger.com/profile/16114043697010364282noreply@blogger.com0tag:blogger.com,1999:blog-7598615455712402973.post-41430231278757185242024-01-25T17:07:00.001-05:002024-01-25T17:20:09.326-05:00Towards Every European Country's Own Crewed Spaceflight, Page 2: saved costs and time using already developed, operational engines.<p style="text-align: center;"><i> Copyright 2024 Robert Clark</i></p><p style="text-align: center;"><i><br /></i></p><p style="text-align: left;"><b><u>Vulcain-based launchers.</u></b></p><p style="text-align: left;"><b> </b>ESA head Josef Aschbacher made the remarkable statement that the Ariane 6 can not be guaranteed to be the launcher of choice in the European launch market:</p><p>“We are worried,” says European rocket chief at prospect of launch competition<br />On the continent, Ariane 6 may be the last launcher with a monopoly.<br />PEGGY HOLLINGER AND SYLVIA PFEIFER, FT - 1/9/2024, 9:18 AM<br /><a href="https://arstechnica.com/space/2024/01/we-are-worried-says-european-rocket-chief-at-prospect-of-launch-competition/">https://arstechnica.com/space/2024/01/we-are-worried-says-european-rocket-chief-at-prospect-of-launch-competition/</a></p><p style="text-align: left;"> In the blog post, "<span style="background-color: white; color: #222222; font-family: inherit;"><a href="http://exoscientist.blogspot.com/2023/06/towards-every-european-countrys-own.html" target="_blank">Towards Every European Country's Own Crewed Spaceflight</a>", I suggested any European country could build their own manned spaceflight capable launcher by buying an Ariane 5 or 6, disposing of the side boosters, and adding 1 or 2 additional Vulcain engines to the core. ArianeSpace might raise a squawk however since it would be using their tech to build a direct competitor to the Ariane 6 and at a cheaper price in not using the large, expensive side boosters.</span></p><p style="text-align: left;"><span style="background-color: white; color: #222222; font-family: inherit;"> Another approach might be to design their own launcher designed around the Vulcain engine. The Vulcain engine developer Snecma, now Safran Aircraft Engines, is independent of ArianeSpace so likely the Vulcain could also be purchased from Safran. Purchasing an already developed and operational engine would save on costs since engine development is typically the biggest development cost for a new launcher. See for example this breakdown on the costs of the Ariane 5:</span></p><div style="background-color: white; color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px;"><span face="-apple-system, BlinkMacSystemFont, "Segoe UI Adjusted", "Segoe UI", "Liberation Sans", sans-serif" style="color: #232629; font-size: var(--fs-title);"><i>Development budget</i></span></div><div style="background-color: white;"><p style="border: 0px; box-sizing: inherit; clear: both; color: #232629; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI Adjusted", "Segoe UI", "Liberation Sans", sans-serif; font-size: 15px; font-stretch: inherit; font-variant-east-asian: inherit; font-variant-numeric: inherit; line-height: inherit; margin-bottom: var(--s-prose-spacing); margin-left: 0px; margin-right: 0px; margin-top: 0px; padding: 0px; vertical-align: baseline;"><i>Again, Ariane 5, from 'Europäische Tragerraketen, band 2', Bernd Leitenberger:</i></p><p style="border: 0px; box-sizing: inherit; clear: both; color: #232629; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI Adjusted", "Segoe UI", "Liberation Sans", sans-serif; font-size: 15px; font-stretch: inherit; font-variant-east-asian: inherit; font-variant-numeric: inherit; line-height: inherit; margin-bottom: var(--s-prose-spacing); margin-left: 0px; margin-right: 0px; margin-top: 0px; padding: 0px; vertical-align: baseline;"><i>Studies and tests 125<br style="box-sizing: inherit;" />solid boosters 355<br style="box-sizing: inherit;" /><b>H120 first stage 270<br style="box-sizing: inherit;" />HM60 (Vulcain) engine and test stands 738</b><br style="box-sizing: inherit;" />other elements of the first stage and boosters 95<br style="box-sizing: inherit;" />upper stage and VEB 200<br style="box-sizing: inherit;" />ground support in Europe 80<br style="box-sizing: inherit;" />Buildings and other structures in Kourou (launch pad) 450<br style="box-sizing: inherit;" />Test flights 185<br style="box-sizing: inherit;" />Total 2498<br style="box-sizing: inherit;" />ESA and CNES management 102</i></p><p style="border: 0px; box-sizing: inherit; clear: both; color: #232629; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI Adjusted", "Segoe UI", "Liberation Sans", sans-serif; font-size: 15px; font-stretch: inherit; font-variant-east-asian: inherit; font-variant-numeric: inherit; line-height: inherit; margin-bottom: var(--s-prose-spacing); margin-left: 0px; margin-right: 0px; margin-top: 0px; padding: 0px; vertical-align: baseline;"><a href="https://space.stackexchange.com/questions/17777/what-is-the-rough-breakdown-of-rocket-costs" style="color: #2288bb; text-decoration-line: none;">https://space.stackexchange.com/questions/17777/what-is-the-rough-breakdown-of-rocket-costs</a></p><p style="border: 0px; box-sizing: inherit; clear: both; color: #222222; font-stretch: inherit; font-variant-east-asian: inherit; font-variant-numeric: inherit; line-height: inherit; margin-bottom: var(--s-prose-spacing); margin-left: 0px; margin-right: 0px; margin-top: 0px; padding: 0px; vertical-align: baseline;"><span style="color: #232629;"><span style="font-family: inherit;"> For our scenario we would not be using solid rockets. So that rather large cost would be saved. Note also in our scenario using the already developed and fully operational Vulcain, the engine development costs and test stand costs would also be saved. For the Ariane 5, the ESA also built entire new launch facilities in Kourou, Guyana in equatorial Africa. For this new launcher we'll assume it will use the already constructed launch facilities at Kourou, or the country where the new launcher is being developed would construct an independent launch facility for their nascent space industry.</span></span></p><p style="border: 0px; box-sizing: inherit; clear: both; color: #222222; font-stretch: inherit; font-variant-east-asian: inherit; font-variant-numeric: inherit; line-height: inherit; margin-bottom: var(--s-prose-spacing); margin-left: 0px; margin-right: 0px; margin-top: 0px; padding: 0px; vertical-align: baseline;"><span style="color: #232629;"><span style="font-family: inherit;"> To sure, we'll assume this new launcher would be developed using the commercial space approach spearheaded by SpaceX. SpaceX demonstrated development costs could be cut by a factor of 10 following this approach:</span></span></p><div style="color: #222222;"><span style="font-family: inherit;">Falcon 9.</span></div><div style="color: #222222;"><span style="font-family: inherit;"><a href="https://en.wikipedia.org/wiki/Falcon_9#Development_history" style="background: none rgb(248, 249, 250); color: #0645ad; text-decoration-line: none;"><span class="tocnumber" style="color: #202122; display: table-cell; padding-left: 0px; padding-right: 0.5em; text-decoration: inherit;">1</span><span class="toctext" style="display: table-cell; text-decoration: inherit;">Development history</span></a><span face="sans-serif" style="background-color: #f8f9fa; color: #202122;"></span></span><ul style="background-color: #f8f9fa; color: #202122; line-height: 1.4; list-style: none; margin: 0px 0px 0px 2em; padding: 0px;"><li class="toclevel-2 tocsection-2" style="margin: 0px 0px 0.1em; padding: 0px;"><a href="https://en.wikipedia.org/wiki/Falcon_9#Conception_and_funding" style="background: none; color: #0645ad; text-decoration-line: none;"><span style="font-family: inherit;"><span class="tocnumber" style="color: #202122; display: table-cell; padding-left: 0px; padding-right: 0.5em; text-decoration: inherit;">1.1</span><span class="toctext" style="display: table-cell; text-decoration: inherit;">Conception and funding</span></span></a></li></ul></div><div style="color: #222222;"><i><span style="font-family: inherit;"><span face="sans-serif" style="color: #202122;">In 2011, SpaceX estimated that Falcon 9 v1.0 development costs were on the order of US$300 million.</span><sup class="reference" id="cite_ref-SpaceX_May_4,_2011_39-0" style="color: #202122; line-height: 1; unicode-bidi: isolate; white-space: nowrap;"><a href="https://en.wikipedia.org/wiki/Falcon_9#cite_note-SpaceX_May_4,_2011-39" style="background: none; color: #0645ad; text-decoration-line: none;">[39]</a></sup><span face="sans-serif" style="color: #202122;"> NASA estimated development costs of US$3.6 billion had a traditional </span><a href="https://en.wikipedia.org/wiki/Cost-plus_contract" style="background-attachment: initial; background-clip: initial; background-image: none; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: #0645ad; text-decoration-line: none;" title="Cost-plus contract">cost-plus contract</a><span face="sans-serif" style="color: #202122;"> approach been used.</span><sup class="reference" id="cite_ref-NAFCOM.pdf_40-0" style="color: #202122; line-height: 1; unicode-bidi: isolate; white-space: nowrap;"><a href="https://en.wikipedia.org/wiki/Falcon_9#cite_note-NAFCOM.pdf-40" style="background: none; color: #0645ad; text-decoration-line: none;">[40]</a></sup><span face="sans-serif" style="color: #202122;"> A 2011 NASA report "estimated that it would have cost the agency about US$4 billion to develop a rocket like the Falcon 9 booster based upon NASA's traditional contracting processes" while "a more commercial development" approach might have allowed the agency to pay only US$1.7 billion".</span><sup class="reference" id="cite_ref-Ars_Tech_seeks_gov_funding_41-0" style="color: #202122; line-height: 1; unicode-bidi: isolate; white-space: nowrap;"><a href="https://en.wikipedia.org/wiki/Falcon_9#cite_note-Ars_Tech_seeks_gov_funding-41" style="background: none; color: #0645ad; text-decoration-line: none;">[41]</a></sup></span></i></div><div style="color: #222222;"><a href="https://en.wikipedia.org/wiki/Falcon_9#Conception_and_funding" style="color: #2288bb; text-decoration-line: none;"><span style="font-family: inherit;">https://en.wikipedia.org/wiki/Falcon_9#Conception_and_funding</span></a></div><div style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px;"><br /></div><div style="color: #222222;"><span style="font-family: inherit;"> Now, several companies world-wide have also shown that following the commercial space approach of using private financing can cut development costs by a factor of 10.</span></div><div style="color: #222222;"><span style="font-family: inherit;"><br /></span></div><div><span style="color: #222222; font-family: inherit;"> The total development cost of the Ariane 5 was </span><span face="sans-serif" style="color: #202122; font-size: 14px;">$</span><span style="color: #222222; font-family: inherit;">2.5 billion in 1990's dollars. Now take into account the costs that wouldn't need to be included, solid booster development, engine development, and launch facilities. This reduces the development cost to $955 million in 1990's dollars. Now consider by following the commercial space approach this could be cut by a factor of 10 to ca. $95 million, or about $200 million in 2024 dollars. </span><span style="color: #222222; font-family: inherit;">Quite remarkable also in particular is the development of the core stage without engines could be done for only about $54 million.</span></div><div><span style="color: #222222; font-family: inherit;"><br /></span></div><div><span style="color: #222222; font-family: inherit;"> So an approx. 10 ton payload capacity all-liquid launcher could be developed for approx. $200 million, by using already developed and operational engines. This launcher would have the advantages, by not using solid rocket boosters, of being capable of reusability and being made manned flight capable.</span></div><div><span style="color: #222222; font-family: inherit;"><br /></span></div><div><span style="color: #222222; font-family: inherit;"> Quite surprising also is how quickly such a manned-flight capable launcher might be developed. ArianeSpace could develop it the most quickly, probably in less than a year. All it would have to do is acknowledge large solid side boosters are not price competitive. As I discussed previously, JAXA showed with its H-II rocket, an additional engine can be added to a core stage for less than $200 million. And SpaceX showed with its Raptor engine that additional Raptors can be added to a core stage on a time scale of just months, not years, even if a new thrust structure is required to accommodate the new engines. </span></div><div><span style="color: #222222; font-family: inherit;"><br /></span></div><div><span style="color: #222222; font-family: inherit;"> But even for those countries making the new launcher from scratch quite surprisingly it could also be done quite rapidly,</span><i style="color: #222222; font-family: inherit;"> assuming it used an already developed and operational engine</i><span style="color: #222222; font-family: inherit;">. A fact not generally </span><span style="color: #222222;">appreciated</span><span style="color: #222222;"><span style="font-family: inherit;"> is how </span>rapidly<span style="font-family: inherit;"> SpaceX was able to develop the Falcon 9 rocket by using the already developed and operational Merlin engine. After the first successful flight of the Falcon 1 in 2008, SpaceX built and successfully launched the Falcon 9 in only two years in 2010. Note because the Falcon 9 had a larger diameter and used 9 engines instead of just one, SpaceX had to use completely different tooling in constructing the Falcon 9.</span></span></div><div><span style="color: #222222;"><span style="font-family: inherit;"><br /></span></span></div><div><span style="color: #222222;"><span style="font-family: inherit;"> Then following the SpaceX example, and the SpaceX commercial space approach, a company could build and launch a 10-ton payload capable launcher in only 2 years by using already developed and operational engines.</span></span></div><div><span style="color: #222222; font-family: inherit;"> </span></div><div><span style="color: #222222; font-family: inherit;"><br /></span></div><div><span style="color: #222222; font-family: inherit;"><b><u>Methane-fueled Prometheus-based launchers.</u></b></span></div><div><br /></div><div> ESA has received much criticism in not keeping up with SpaceX on reusability. The Ariane 6 in fact won't be reusable and it is now acknowledged it won't be competitive to the SpaceX Falcon 9 in price, necessitating hundred million dollar subsidies yearly to stay afloat. </div><div><br /></div><div> Recognizing the need for reusability in future launchers, ESA has begun the development of the methane-fueled, reusable <a href="https://en.wikipedia.org/wiki/Prometheus_(rocket_engine)" target="_blank">Prometheus engine</a>. And through its subsidiary Maiaspace, ArianeSpace is developing an all-liquid reusable launcher using the Prometheus engine for launch:</div><div><br /></div><div><div>ArianeGroup to Increase MaiaSpace Investment to €125M</div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgXduj0rPx3fQ_W_lL4Un6KylCXsyxc4Vz3W99ukWSbNuTNDN3eovyOUrcES_XjoQ7afRfIAqRqj5wYaHFA0u94HMSX4Jj7d-I7jO9BnXO-68rUvmXK9jS_X9ajQdgW_CYCrQ6SBOa-1aVFkSsRBOzG1p3KZl5t1r2ZNMIsy4qIQTowemOh1XA2yDPuaWY/s630/Amia-630x500.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="500" data-original-width="630" height="508" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgXduj0rPx3fQ_W_lL4Un6KylCXsyxc4Vz3W99ukWSbNuTNDN3eovyOUrcES_XjoQ7afRfIAqRqj5wYaHFA0u94HMSX4Jj7d-I7jO9BnXO-68rUvmXK9jS_X9ajQdgW_CYCrQ6SBOa-1aVFkSsRBOzG1p3KZl5t1r2ZNMIsy4qIQTowemOh1XA2yDPuaWY/w640-h508/Amia-630x500.jpg" width="640" /></a></div><div><br /></div><div><a href="https://europeanspaceflight.com/arianegroup-to-increase-maiaspace-investment-to-e125m/">https://europeanspaceflight.com/arianegroup-to-increase-maiaspace-investment-to-e125m/</a></div><div><br /></div><div> The MaiaSpace launcher will be capable of about 1,500 kg payload to LEO as an expendable rocket, using three Prometheus engines at ca. 100-ton thrust capability. It is expected to make its first launch in 2025.</div><div><br /></div><div> It is illuminating to make a comparison to the early development of SpaceX. The Falcon 1 had an approx. 600 kg to LEO capability using a single ~100-ton thrust Merlin engine. It had its first successful launch in 2008. Remarkably just 2 years later in 2010, SpaceX had the 9 Merlin-engine Falcon 9 rocket make a successful launch at a ca. 10-ton payload to LEO capacity.</div><div><br /></div><div> Then following the SpaceX example, MaiaSpace using 9 Prometheus engines could have a 10-ton to LEO capable launcher available in 2027. This could be man-rated to be manned flight capable.</div><div><br /></div><div> Then going by the SpaceX example of the $300 million development cost of Falcon 9, and considering engine development cost makes up the bulk of launcher development cost, any European country using an already developed and operational Prometheus engine could have a 10-ton to LEO capable launcher at less than $150 million development cost following the commercial space approach.</div><div><br /></div><div> And again following the SpaceX example such a launcher could be built and launched within 2 years.</div><div><br /></div><div><b><u>Manned Space Capsules.</u></b></div><div><b><u><br /></u></b></div><div> ESA has announced opening a competition among European companies for cargo capsules to deliver supplies to the ISS, with manned capsules to follow in development:</div><div><br /></div><div><div>ESA to start commercial cargo program</div><div>Jeff Foust</div><div>November 6, 2023</div><div><a href="https://spacenews.com/esa-to-start-commercial-cargo-program/">https://spacenews.com/esa-to-start-commercial-cargo-program/</a></div></div><div><br /></div><div> SpaceX and Orbital Sciences, now a subsidiary of Northrup Grumman, with their Dragon and Cygnus cargo capsules, showed space capsules like launchers also could be developed at costs 1/10 that of the usual government-financed ones following the private financing approach of commercial space. </div><div><br /></div><div> Then I advise the European companies entering the competition follow the commercial space approach in developing their space capsules. They could accept seed funding from ESA to get started, but the bulk of the development costs should come from private funding. Note that winning these seed dollars from the ESA could be used as a selling point in acquiring the private funding.</div><div><br /></div><div> According to the SpaceNews article the cargo capsules are expected to be ready by 2027 or 2028. It is notable that this is around the same time MaiaSpace might be able to have a 10-ton to LEO capable launcher ready. </div><div><br /></div><div> Because of this I advise the cargo capsules and manned capsules be developed concurrently. It is my thesis that manned capsules can also be developed at costs in the few hundred million dollars cost range by following the commercial space approach as found with cargo space capsules.</div><div><br /></div><div> It is notable in this regard that when SpaceX accepted NASA funding for the development of the manned version of the Dragon capsule, costs ballooned to the billion dollar range. I'm arguing the costs were that high <i>because</i> NASA was paying for it.</div><div> </div><div><br /></div><div><br /></div><div> Robert Clark</div></div></div>Robert Clarkhttp://www.blogger.com/profile/16114043697010364282noreply@blogger.com2tag:blogger.com,1999:blog-7598615455712402973.post-73213120795192015872024-01-23T11:42:00.002-05:002024-01-23T13:41:29.658-05:00Possibilities for a single launch architecture of the Artemis missions, Page 4: lightweight landers from NRHO to the lunar surface.<p style="text-align: center;"> <i>Copyright 2024 Robert Clark</i></p><p style="text-align: center;"><br /></p><p style="text-align: left;"> Congress is becoming increasingly concerned that with the continuing delays of the Artemis missions that China may beat the U.S. back to the Moon:</p><p>US must beat China back to the moon, Congress tells NASA.<br />By Mike Wall <br /><i>'It's no secret that China has a goal to surpass the United States by 2045 as global leaders in space. We can't allow this to happen.'</i><br /><a href="https://www.space.com/us-win-moon-race-china-congress-artemis-hearing">https://www.space.com/us-win-moon-race-china-congress-artemis-hearing</a></p><p> I had previously proposed correcting an error in the design of Orion's service module that instead of making it larger than Apollo's service module because of Orion's twice larger size, instead made it 1/3rd <i>smaller:</i></p><h3 class="post-title entry-title" itemprop="name" style="background-color: white; color: #222222; font-feature-settings: normal; font-kerning: auto; font-optical-sizing: auto; font-stretch: normal; font-variant-alternates: normal; font-variant-east-asian: normal; font-variant-numeric: normal; font-variant-position: normal; font-variation-settings: normal; font-weight: normal; line-height: normal; margin: 0.75em 0px 0px; position: relative;"><span style="font-family: inherit; font-size: small;">Possibilities for a single launch architecture of the Artemis missions, Page 2: using the Boeing Exploration Upper Stage.</span></h3><p></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgtJP06IBN5vTIWCaGRkeFcJXlkGqcHEA06FekjHJJKiZtL5I2kDC4YYOsXJXiu08lT45z3skTKIudhbpUoj7AeUaZDMIrYPE0Ly-ofGPlIOIcxd5Tj9Wl_QOix0E1sQSGwJwFwXmyq_gYq2BBa9rmqr5YVfRauWpzdfXiRGjytwVlEMpE53gV2hfUSjCs/s640/6A41E7D6-5965-4D9D-A692-4D5421C042F6.jpeg" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="360" data-original-width="640" height="360" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgtJP06IBN5vTIWCaGRkeFcJXlkGqcHEA06FekjHJJKiZtL5I2kDC4YYOsXJXiu08lT45z3skTKIudhbpUoj7AeUaZDMIrYPE0Ly-ofGPlIOIcxd5Tj9Wl_QOix0E1sQSGwJwFwXmyq_gYq2BBa9rmqr5YVfRauWpzdfXiRGjytwVlEMpE53gV2hfUSjCs/w640-h360/6A41E7D6-5965-4D9D-A692-4D5421C042F6.jpeg" width="640" /></a></div><a href="https://exoscientist.blogspot.com/2023/08/possibilities-for-single-launch.html">https://exoscientist.blogspot.com/2023/08/possibilities-for-single-launch.html</a><p></p><p> The proposal was to give an additional approx. 10 tons propellant to the service module. This would allow the Orion capsule/service module stack plus an Apollo-size lander to be carried all the way to low lunar orbit, not just to NRHO(near-rectilinear halo orbit). </p><p> This though because of the higher payload may require use of the higher thrust J-2X engine on the Boeing EUS(upper stage) rather than the 4 RL-10 engines now planned on the SLS Block 1B. It's higher thrust would result in a greater payload to LEO and TLI, perhaps to ca. 120 tons to LEO rather than the 105 tons planned to LEO.</p><p>This approach requires additional propellant tanks be added to the service module and a change in the EUS upper stage engine to the J-2X. As I discussed in that blog post, it may also require an additional Centaur V sized third stage be added atop the Boeing EUS. This is dependent on what is the TLI(trans lunar injection) payload for the Boeing EUS using the J-2X engine. It may be it can perform the needed TLI payload without an additional Centaur V 3rd stage.</p><p> In any case, I'll propose here an alternative approach to a single launch Artemis architecture without increasing the service module propellant load. This again will use a light-weight Apollo-sized lander with all the components of Orion capsule/Service Module/lunar lander all carried on that one single SLS launch. Because of the lower propellant load on the service module though I'll also send it to NRHO instead of to low lunar orbit.</p><p> Note the NRHO was chosen by NASA as the orbital location because it has a lower delta-v requirement to get there than going to low lunar orbit. Here’s the the delta-v requirements:</p><p></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjTp6yksdIRiCg97erJVXpYpJjPpNpWjReHZqlk_8f2-qBgIklC1IwjjW-2TNUUsboobPhOwA4iHcxaZFAIwvyuuVsnhlaqagoF9XgZnB6q3vIBfPJBzgfZORlWFQ8XLDvSMz4Ge1otD0GFSnNQgf7I3OzWLZkNh3fTFy7ZlAEOpvH_b9GIcwL7nwiMIyQ/s1597/PDzVmq2.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="897" data-original-width="1597" height="360" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjTp6yksdIRiCg97erJVXpYpJjPpNpWjReHZqlk_8f2-qBgIklC1IwjjW-2TNUUsboobPhOwA4iHcxaZFAIwvyuuVsnhlaqagoF9XgZnB6q3vIBfPJBzgfZORlWFQ8XLDvSMz4Ge1otD0GFSnNQgf7I3OzWLZkNh3fTFy7ZlAEOpvH_b9GIcwL7nwiMIyQ/w640-h360/PDzVmq2.png" width="640" /></a></div><p></p><p> The second group of delta-v’s shows the delta-v to NRHO as 0.45 km/s and the delta-v to and from the lunar surface from NRHO as 2.75 km/s, or 5.5 km/s round trip.</p><p> I’ve seen various numbers for the Orion and service module dry mass and propellant mass. I’ll use 16.5 total dry mass for the Orion+service module together, and 9 tons of service module propellant mass, but only 8.6 tons of this as usable propellant because of residuals.</p><p> Then we'll use 6 tons of Service module propellant to get the Orion/Service Module/lunar lander to NRHO after being placed on TLI trajectory by the EUS, for the 16.5 ton Orion/Service Module dry mass, and 15 tons gross mass Apollo-sized lander with 2.6 tons left over for the return trip.</p><p> We'll need every bit of performance to accomplish the mission within these constraints. So we'll assume we can get a 324 s Isp out of the storable propellant engines on the service module. This is higher than specified for the Orion service modules engines but is doable because of the storable propellant Aestus engine on the <a href="https://www.esa.int/Enabling_Support/Space_Transportation/Launch_vehicles/Storable_Propellant_Stage_EPS" style="background-color: white; color: #33aaff; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px;" target="_blank">Ariane 5 EPS storable propellant upper stage</a> which gets this vacuum Isp. We'll assume we can get this increased Isp by using a larger expansion ratio nozzle or even by swapping out the engine on the service module to use the Aestus engine. Then we get:</p><p>324*9.81Ln(1 + 6/(16.5 + 15 + 2.6 + 0.4)) = 510 m/s, or 0.51 km/s, sufficient for placing the stack in the NRHO orbit, where the 0.4 in the equation is for the unburnt residuals.</p><p> Then with the 2.6 tons usable propellant left over for the return trip, after the lander is jettisoned, we get:</p><p>324*9.81Ln(1 + 2.6/(16.5 + 0.4)) = 450 m/s, 0.45 km/s, sufficient for the Orion return.</p><p> To increase performance even more we may want to switch even to the <a href="http://www.astronautix.com/r/rs-72.html" target="_blank">RS-72 engine</a>. This is a turbopump-fed storable propellant engine with a vacuum Isp of 340s. It achieves this by using a higher chamber pressure of 60 bar and higher nozzle expansion ratio of 300 to 1 than the Aestus engine. A turbopump engine also has lower residuals, typically less than 1%. A disadvantage is that pressure-fed engines are simpler with fewer moving parts, and so higher reliability, important for an engine to place the spacecraft in orbit and for leaving orbit.</p><p> Now for the ca. 15 ton gross mass lander, because of the higher delta- v needed from NRHO we’ll use hydrolox rather than storable propellant stage. The <a href="http://www.braeunig.us/space/specs/ariane.htm" target="_blank">Ariane 4 H10</a> hydrolox upper stage had a 11.8 ton propellant mass and 1.2 ton dry mass. We’ll use a 2 ton dry mass of the crew module:</p><p>ORBITAL PROPOSES FUTURE DEEP SPACE APPLICATIONS FOR CYGNUS.<br />SPACEFLIGHT INSIDER<br />MAY 1ST, 2014<br /><i>Orbital’s proposal, outlined in this PDF, involves docking a Cygnus spacecraft with Orion to serve as a habitation and logistics module on longer flights. For these missions, the re-purposed Cygnus would be called the Exploration Augmentation Module (EAM). <b>With its current life support systems used to transport pressurized cargo and experiments to the ISS, Cygnus is stated as being already suitable for the long term support of a crew.</b> While berthed to Orion, Cygnus could support a crew of four for up to 60 days. Cygnus also has the capability of storing food, water, oxygen, and waste and features its own power and propulsion systems. The EAM would utilize the enhanced configuration Cygnus, which will begin flying larger cargoes to the ISS beginning with CRS-4 in 2015. An even larger version is also being proposed, featuring a 4-segment pressurized cargo module.</i></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjjhhfiFO9Cr9pGI2R0FmWR9NxX2crgkDOm4GQGX2vFr_bPIvFEcBHP74x4DRXOVgG-exjFPbgRYtT_HQtuzMVNSYtRC9om88dkmDXIuOPqyx5vQ1T2Oj3u7_eS29u0u3tL2heSaOBNs-zvyQllpi2SvGe_hrseVYGZHgCpzfYkXl1cjymnWkRiTxT6awk/s1053/Cygnus-Congigurations.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="679" data-original-width="1053" height="412" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjjhhfiFO9Cr9pGI2R0FmWR9NxX2crgkDOm4GQGX2vFr_bPIvFEcBHP74x4DRXOVgG-exjFPbgRYtT_HQtuzMVNSYtRC9om88dkmDXIuOPqyx5vQ1T2Oj3u7_eS29u0u3tL2heSaOBNs-zvyQllpi2SvGe_hrseVYGZHgCpzfYkXl1cjymnWkRiTxT6awk/w640-h412/Cygnus-Congigurations.jpg" width="640" /></a></div><p><a href="https://www.spaceflightinsider.com/missions/commercial/orbital-proposes-future-deep-space-applications-cygnus/">https://www.spaceflightinsider.com/missions/commercial/orbital-proposes-future-deep-space-applications-cygnus/</a></p><p> Note though the phrasing here is ambiguous. The Cygnus capsule as used as a cargo transport to the ISS contains air, as it would have to for the astronauts at the ISS opening it to retrieve the cargo, but not life support systems. I'm inclined to believe for the usage cited in this article it would be taking life support from the Orion capsule. Then the calculations need to be made for how much mass it would take for life support, thermal management, consumables for an independent crew module.</p><p> Now for the delta-v calculation for our hydrolox lander, we'll assume we can match the max 465 s Isp of the RL-10 engine by giving the Ariane 4 upper stage engine a nozzle extension as used on the RL-10, then we get:</p><p>465*9.81Ln(1 + 11.8/(1.2 + 2)) = 7,000 m/s, 7 km/s. This is quite a bit higher than the 5.5 km/s needed for the round trip from NRHO to the lunar surface and back again. But it uses hydrolox propellant so needs extra mass for low-boiloff tech. </p><p> Low boiloff-tech and long duration hydrolox stages are an important enabling technology. ULA engineers and ULA CEO Tory Bruno have written about this extensively in regards to for example the proposed ACES derivative of the Centaur upper stage. Because of the prior research on low-boiloff tech, an operational version to be fielded in a short time frame to be used on the Artemis missions likely can be done. </p><p> This shows a single launch mission is doable if going to NRHO, but it is not my preferred plan. A complete orbit around the Moon at NRHO altitude takes about a week, and for the Orion capsule being at NRHO and not low lunar orbit, the lander's crew would have to remain on the Moon about a week before they could return to the Orion in the NRHO orbit. The landers crew module would have to be larger with heavier life support and consumables in this scenario.</p><p> If instead the Orion was at low lunar orbit it takes two hours to complete an orbit and the lunar lander could launch every two hours to rendezvous with the Orion.</p><p> Since the Orion's service module being given an insufficient propellant load is such an obvious design mistake, the preferred route to take would be to correct that error, thereby allowing the missions to take place from low lunar orbit instead of from NRHO.</p><p><br /></p><p> Robert Clark</p><p><br /></p><p><br /></p><div><br /></div>Robert Clarkhttp://www.blogger.com/profile/16114043697010364282noreply@blogger.com1tag:blogger.com,1999:blog-7598615455712402973.post-58466832266461504722024-01-16T11:12:00.000-05:002024-01-16T11:12:46.151-05:00Towards a manned Indian launcher: an all-liquid LVM3.<p style="text-align: center;"> <i>Copyright 2024 Robert Clark</i></p><p style="text-align: center;"><i><br /></i></p><p style="text-align: left;"> In the blog post, "<span style="background-color: white; color: #222222; font-family: inherit;"><a href="https://exoscientist.blogspot.com/2014/12/a-liquid-fueled-indian-manned-launcher.html" target="_blank">A liquid-fueled Indian manned launcher. UPDATED</a>", I suggested the launcher based on the liquid-fueled LVM3 core stage, but replacing the 2 solid side boosters by </span><span style="background-color: white; color: #222222;"><span style="font-family: inherit;">4 of the liquid-fueled strap on boosters used on the earlier design, the GSLV Mk. II. Here I'll suggest instead a version using the LVM3 core but getting the added thrust needed for lift-off by adding a 3rd Vikas engine.</span></span></p><p style="text-align: left;"><span style="background-color: white; color: #222222;"></span></p><div class="separator" style="clear: both; text-align: center;"><a href="http://spaceflight101.com/spacerockets/wp-content/uploads/sites/17/2015/08/5281787_orig.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="782" data-original-width="384" height="640" src="http://spaceflight101.com/spacerockets/wp-content/uploads/sites/17/2015/08/5281787_orig.jpg" width="314" /></a></div><p></p><h2 style="background-color: white; border: 0px; color: #333333; font-family: "Open Sans", sans-serif; font-stretch: inherit; font-variant-east-asian: inherit; font-variant-numeric: inherit; font-weight: normal; line-height: 1.2; margin: 0px; outline: 0px; padding: 0px 0px 18px; text-align: center; vertical-align: baseline;"><span style="font-size: small;"><i>GSLV Mk. III Specifications</i></span></h2><div><span style="font-size: small;"><i><br /></i></span></div><div class="separator" style="clear: both; text-align: center;"></div><div id="Mappe1_4760" x:publishsource="Excel">I have argued using such large SRB's are not price competitive:</div><div id="Mappe1_4760" x:publishsource="Excel"><h3 class="post-title entry-title" itemprop="name" style="background-color: white; color: #222222; font-stretch: normal; font-variant-east-asian: normal; font-variant-numeric: normal; font-weight: normal; line-height: normal; margin: 0.75em 0px 0px; position: relative;"><span style="font-family: inherit; font-size: small;"><a href="https://exoscientist.blogspot.com/2023/06/towards-revolutionary-advance-in.html" target="_blank">Towards a revolutionary advance in spaceflight: an all-liquid Ariane 6.</a></span></h3></div><div id="Mappe1_4760" x:publishsource="Excel"><br /></div><div id="Mappe1_4760" x:publishsource="Excel">It is very likely the same is true for the GSLV Mk III. Then we'll replace the two SRB boosters by an additional core engine.</div><div id="Mappe1_4760" x:publishsource="Excel"><br /></div><div id="Mappe1_4760" x:publishsource="Excel"> The GSLV Mk. III core stage has specifications listed as:</div><div id="Mappe1_4760" x:publishsource="Excel"><br /></div><div id="Mappe1_4760" x:publishsource="Excel"><h2 class="wsite-content-title" style="background-color: white; color: #272e34; font-family: Arial, Helvetica, sans-serif; font-size: 15px; line-height: 1.3; margin: 0px; padding: 0.3em 0px; position: relative; text-align: center;"><span style="font-size: medium;">Core Stage</span></h2><div style="background-color: white;"><div align="left" class="wcustomhtml" id="966606277100378228" style="overflow-y: hidden; width: 454px;"><div align="center" id="info_25110" style="color: #666666; font-family: Arial, Helvetica, sans-serif; font-size: 12px;" x:publishsource="Excel"><table border="0" cellpadding="0" cellspacing="0" style="border-collapse: collapse; table-layout: fixed; width: 443px;" x:str=""><colgroup><col style="width: 124pt;" width="165"></col><col style="width: 207pt;" width="276"></col><col style="width: 2pt;" width="2"></col></colgroup><tbody><tr height="2" style="height: 1.5pt;"><td class="xl1525110" height="2" style="color: windowtext; font-family: Arial; font-size: 10pt; height: 1.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap; width: 124pt;" width="165"></td><td class="xl2225110" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap; width: 207pt;" width="276"></td><td class="xl1525110" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap; width: 2pt;" width="2"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2425110" height="22" style="background: silver; border: 1pt solid windowtext; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">Type</td><td class="xl2425110" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top: 1pt solid windowtext; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">L-110</td><td class="xl1525110" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2425110" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">Length</td><td class="xl2525110" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">21.26m</td><td class="xl1525110" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2425110" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">Diameter</td><td class="xl2425110" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">4.0m</td><td class="xl1525110" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2425110" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">Fuel</td><td class="xl2525110" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">Unsymmetrical Dimethylhydrazine</td><td class="xl1525110" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2425110" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">Oxidizer</td><td class="xl2525110" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">Nitrogen Tetroxide</td><td class="xl1525110" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2425110" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">Inert Mass</td><td class="xl2525110" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">10,600kg</td><td class="xl1525110" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2425110" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">Propellant Mass</td><td class="xl2525110" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">115,000kg</td><td class="xl1525110" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2425110" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">Launch Mass</td><td class="xl2525110" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">125,600kg</td><td class="xl1525110" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2425110" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">Propellant Tanks</td><td class="xl2525110" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">Aluminum Alloy</td><td class="xl1525110" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2625110" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 124pt;" width="165">Fuel</td><td class="xl2625110" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 207pt;" width="276">UH25 - 75% UDMH, 25% Diazane</td><td class="xl2325110" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 2pt;" width="2"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2625110" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 124pt;" width="165">Oxidizer</td><td class="xl2625110" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 207pt;" width="276">Nitrogen Tetroxide</td><td class="xl2325110" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 2pt;" width="2"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2625110" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 124pt;" width="165">Propulsion</td><td class="xl2625110" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 207pt;" width="276">2 Vikas 2</td><td class="xl2325110" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 2pt;" width="2"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2625110" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 124pt;" width="165">Thrust (SL)</td><td class="xl2625110" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 207pt;" width="276">677kN</td><td class="xl2325110" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 2pt;" width="2"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2625110" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 124pt;" width="165">Thrust (Vac)</td><td class="xl2625110" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 207pt;" width="276">766kN</td><td class="xl2325110" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 2pt;" width="2"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2625110" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 124pt;" u1:str="Impulse " width="165">Specific Impulse</td><td class="xl2625110" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 207pt;" width="276">293 sec</td><td class="xl2325110" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 2pt;" width="2"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2625110" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 124pt;" u1:str="Engine Dry Weight " width="165">Engine Dry Weight</td><td class="xl2625110" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 207pt;" width="276">900kg</td><td class="xl2325110" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 2pt;" width="2"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2625110" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 124pt;" width="165">Engine Length</td><td class="xl2625110" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 207pt;" width="276">2.87m</td><td class="xl2325110" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 2pt;" width="2"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2625110" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 124pt;" width="165">Engine Diameter</td><td class="xl2625110" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 207pt;" width="276">0.99m</td><td class="xl2325110" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 2pt;" width="2"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2625110" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 124pt;" width="165">Chamber Pressure</td><td class="xl2625110" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 207pt;" width="276">58.5bar</td><td class="xl2325110" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 2pt;" width="2"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2625110" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 124pt;" width="165">Mixture Ratio</td><td class="xl2625110" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 207pt;" width="276">1.7 (Ox/Fuel)</td><td class="xl2325110" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 2pt;" width="2"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2625110" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 124pt;" width="165">Turbopump Speed</td><td class="xl2625110" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 207pt;" width="276">10,000rpm</td><td class="xl2325110" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 2pt;" width="2"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2625110" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 124pt;" width="165">Flow Rate</td><td class="xl2625110" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 207pt;" width="276">275kg/s</td><td class="xl2325110" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 2pt;" width="2"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2625110" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 124pt;" width="165">Area Ratio</td><td class="xl2625110" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 207pt;" width="276">13.88</td><td class="xl2325110" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 2pt;" width="2"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2625110" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 124pt;" width="165">Attitude Control</td><td class="xl2625110" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 207pt;" width="276">Engine Gimbaling</td><td class="xl2325110" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 2pt;" width="2"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2625110" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 124pt;" width="165">Ignition</td><td class="xl2625110" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 207pt;" width="276">T+110s</td><td class="xl2325110" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 2pt;" width="2"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2625110" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 124pt;" width="165">Burn Time</td><td class="xl2625110" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 207pt;" width="276">200s</td><td class="xl2325110" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 2pt;" width="2"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2625110" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 124pt;" width="165">Stage Separation</td><td class="xl2625110" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 207pt;" width="276">Active/Passive Collets</td><td class="xl2325110" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 2pt;" width="2"></td></tr></tbody></table></div><div align="center" id="info_25110" style="color: #666666; font-family: Arial, Helvetica, sans-serif; font-size: 12px;" x:publishsource="Excel"><br /></div><div id="info_25110" style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px;" x:publishsource="Excel"></div></div></div></div><p style="text-align: left;"><span style="background-color: white; color: #222222;"><span style="font-family: inherit;"> The Vikas 2 engine provides a thrust of 677 kN at sea level, 69 tons-force. The two on the core would be enough just to loft the core only. But we need enough thrust to liftoff a second stage and payload also. So we'll give the core a third Vikas engine.</span></span></p><p style="text-align: left;"><span style="background-color: white; color: #222222;"><span style="font-family: inherit;"> The weight of the Vikas is 900 kg. Then the dry mass of the stage with an additional Vikas will be 11,500 kg. </span></span></p><div id="info_25110" style="background-color: white; color: #222222;" x:publishsource="Excel"><span style="font-family: inherit;">The cryogenic upper stage has specifications listed as:</span></div><div id="info_25110" style="background-color: white; color: #222222;" x:publishsource="Excel"><span style="font-family: inherit;"><br /></span></div><div id="info_25110" style="background-color: white; color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px;" x:publishsource="Excel"><h2 class="wsite-content-title" style="color: #272e34; font-family: Arial, Helvetica, sans-serif; font-size: 15px; line-height: 1.3; margin: 0px; padding: 0.3em 0px; position: relative; text-align: center;"><span style="font-size: medium;">Cryogenic Upper Stage</span></h2><div style="color: #666666; font-family: Arial, Helvetica, sans-serif; font-size: 12px;"><div align="left" class="wcustomhtml" id="150893905414936350" style="overflow-y: hidden; width: 454px;"><div align="center" id="angara_14102" x:publishsource="Excel"><table border="0" cellpadding="0" cellspacing="0" style="border-collapse: collapse; table-layout: fixed; width: 443px;" x:str=""><colgroup><col style="width: 124pt;" width="165"></col><col style="width: 207pt;" width="276"></col><col style="width: 2pt;" width="2"></col></colgroup><tbody><tr height="2" style="height: 1.5pt;"><td class="xl1514102" height="2" style="color: windowtext; font-family: Arial; font-size: 10pt; height: 1.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap; width: 124pt;" u1:str="Engine Dry Weight " width="165"></td><td class="xl2214102" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap; width: 207pt;" width="276"></td><td class="xl1514102" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap; width: 2pt;" width="2"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2314102" height="22" style="background: silver; border: 1pt solid windowtext; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">Type</td><td class="xl2314102" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top: 1pt solid windowtext; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;" x:str="C-25 Cryogenic Upper Stage ">C-25 Cryogenic Upper Stage</td><td class="xl1514102" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2314102" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">Length</td><td class="xl2414102" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">13.32m</td><td class="xl1514102" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2314102" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">Diameter</td><td class="xl2314102" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">4.0m</td><td class="xl1514102" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2314102" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">Fuel</td><td class="xl2414102" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">Liquid Hydrogen</td><td class="xl1514102" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2314102" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">Oxidizer</td><td class="xl2414102" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">Liquid Oxygen</td><td class="xl1514102" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2314102" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">Inert Mass</td><td class="xl2414102" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">~4,000kg</td><td class="xl1514102" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2314102" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">Propellant Mass</td><td class="xl2414102" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">25,000kg</td><td class="xl1514102" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2314102" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">Launch Mass</td><td class="xl2414102" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">~29,000kg</td><td class="xl1514102" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2314102" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">Propellant Tanks</td><td class="xl2414102" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">Aluminum Alloy</td><td class="xl1514102" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2314102" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">Propulsion</td><td class="xl2414102" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">CE-20</td><td class="xl1514102" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2314102" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">Engine Type</td><td class="xl2414102" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">Gas Generator</td><td class="xl1514102" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2314102" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">Thrust - Vacuum</td><td class="xl2414102" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">200kN</td><td class="xl1514102" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2314102" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">Operational Range</td><td class="xl2414102" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">180-220kN</td><td class="xl1514102" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2314102" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">Specific Impulse Vac</td><td class="xl2414102" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">443s</td><td class="xl1514102" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2314102" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">Engine Mass</td><td class="xl2414102" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">588kg</td><td class="xl1514102" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2314102" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">Chamber Pressure</td><td class="xl2414102" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">60bar</td><td class="xl1514102" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2314102" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">Mixture Ratio</td><td class="xl2414102" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;">5.05</td><td class="xl1514102" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2514102" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 124pt;" width="165">Area Ratio</td><td class="xl2614102" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 207pt;" width="276" x:num="">100</td><td class="xl1514102" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2514102" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 124pt;" width="165">Thrust to Weight</td><td class="xl2614102" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 207pt;" width="276">34.7</td><td class="xl1514102" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2514102" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 124pt;" width="165">Burn Time</td><td class="xl2514102" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 207pt;" width="276">580s</td><td class="xl1514102" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2514102" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 124pt;" width="165">Guidance</td><td class="xl2514102" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 207pt;" width="276">Inertial Platform, Closed Loop</td><td class="xl1514102" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2514102" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 124pt;" width="165">Attitude Control</td><td class="xl2514102" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 207pt;" width="276">2 Vernier Engines</td><td class="xl1514102" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;"></td></tr><tr height="22" style="height: 16.5pt;"><td class="xl2514102" height="22" style="background: silver; border-bottom: 1pt solid windowtext; border-left: 1pt solid windowtext; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; height: 16.5pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 124pt;" width="165">Restart Capability</td><td class="xl2514102" style="background: silver; border-bottom: 1pt solid windowtext; border-left-style: none; border-right: 1pt solid windowtext; border-top-style: none; color: windowtext; font-family: Arial, sans-serif; font-size: 12pt; font-weight: 700; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; width: 207pt;" width="276">RCS for Coast Phase</td><td class="xl1514102" style="color: windowtext; font-family: Arial; font-size: 10pt; padding-left: 1px; padding-right: 1px; padding-top: 1px; vertical-align: bottom; white-space: nowrap;"><br /></td></tr></tbody></table></div></div></div></div><p style="text-align: left;"><span style="background-color: white; color: #222222;"><span style="font-family: inherit;"> Now plug in the data for the Silverbirdastronautics.com payload estimator:</span></span></p><p style="text-align: left;"><span style="background-color: white; color: #222222;"></span></p><div class="separator" style="clear: both; text-align: center;"><span style="background-color: white; color: #222222;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj9dWhakzHsoLFX5MJkovPyZAsVnqLEeGKH1__kF2bLYoCi5fbZtMY27FB5kfV5KD4i_fZ9YngkM-ThAQ30XmM7Kwk3u0X6PQ0umStSdnPyo2sRgolD8-X6c3-UMsNQg_auiKWSgn4e4r24_h_z7B6vX4jcuIGnr3VNjwq1dRCXxHx-gB3kqKrclGLYS_4/s676/GSLV3%20inputs.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="597" data-original-width="676" height="566" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj9dWhakzHsoLFX5MJkovPyZAsVnqLEeGKH1__kF2bLYoCi5fbZtMY27FB5kfV5KD4i_fZ9YngkM-ThAQ30XmM7Kwk3u0X6PQ0umStSdnPyo2sRgolD8-X6c3-UMsNQg_auiKWSgn4e4r24_h_z7B6vX4jcuIGnr3VNjwq1dRCXxHx-gB3kqKrclGLYS_4/w640-h566/GSLV3%20inputs.JPG" width="640" /></a></span></div><span style="background-color: white; color: #222222;"><br /><span style="font-family: inherit;">Where we assume by just using a nozzle extension the Isp can be raised from 443s to the 465s max Isp of the RL10 engine.</span></span><p></p><p style="text-align: left;"><span style="background-color: white; color: #222222;"><span style="font-family: inherit;"> The resulting payload to LEO is:</span></span></p><p style="text-align: left;"><span style="background-color: white; color: #222222;"></span></p><div class="separator" style="clear: both; text-align: center;"><span style="background-color: white; color: #222222;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi8u14lVY_AZm_UpH9ymx62AQrKxU4RTq0FuUX9vgwmmsEc4X9I_2POz2z_c4gri7CO1QLYyOu-5OS9SDMK447Cg5ZI-cn3VHfrutnI3fj8C4G7EXrXgLzAXnqVaXgFq6JkJyO3Jdf-4f54LBYom2Rdgr6XgjR2AcQSlospNWs8qsaCPcQfLkLOPM9tjR4/s688/GSLV3%20results.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="592" data-original-width="688" height="550" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi8u14lVY_AZm_UpH9ymx62AQrKxU4RTq0FuUX9vgwmmsEc4X9I_2POz2z_c4gri7CO1QLYyOu-5OS9SDMK447Cg5ZI-cn3VHfrutnI3fj8C4G7EXrXgLzAXnqVaXgFq6JkJyO3Jdf-4f54LBYom2Rdgr6XgjR2AcQSlospNWs8qsaCPcQfLkLOPM9tjR4/w640-h550/GSLV3%20results.JPG" width="640" /></a></span></div><span style="background-color: white; color: #222222;"><span style="font-family: inherit;"><br /></span></span><p></p><p style="text-align: left;"><span style="background-color: white; color: #222222;"><span style="font-family: inherit;"> This is half the 10 ton payload of the current version of the LVM3 with the large solid side boosters. However, it has the advantage of not using the problematical solid side boosters with their safety concerns for manned flights. </span></span></p><p style="text-align: left;"><span style="background-color: white; color: #222222;"><span style="font-family: inherit;"> The all-liquid version is also likely to be significantly cheaper than the one with solid side boosters as large solid boosters are not price competitive to just using an additional liquid fueled engine.</span></span></p><p style="text-align: left;"><span style="background-color: white; color: #222222;"><span style="font-family: inherit;">It is notable a 5 ton class launcher is sufficient to launch a crewed capsule to orbit since the Gemini capsule had a toal mass of 3,800 kg:</span></span></p><p><span style="color: #222222;">GEMINI SPECIFICATIONS</span></p><p><span style="color: #222222;">First flight: 8-Apr-1964; first manned flight 23-Mar-1965 (Gemini 3)<br /></span><span style="color: #222222;">Last flight: 11-Nov-1966 (Gemini 12)<br /></span><span style="color: #222222;">Number of flights: 13 total; 10 manned<br /></span><span style="color: #222222;">Principal uses: manned earth orbit rendezvous, docking, EVA tests<br /></span><span style="color: #222222;">Unit cost: $13.00 million<br /></span><span style="color: #222222;">Crew size: 2<br /></span><span style="color: #222222;">Overall length: 5.7 m<br /></span><span style="color: #222222;">Maximum diameter: 3.05 m<br /></span><span style="color: #222222;">Habitable volume: 2.55 m3<br /></span><span style="color: #222222;"><b><i>Launch mass: 3,851 kg</i></b><br /></span><span style="color: #222222;">Propellant mass: 455 kg total<br /></span><span style="color: #222222;">RCS total impulse: 1,168 kNs<br /></span><span style="color: #222222;">Primary engine thrust: 710 N<br /></span><span style="color: #222222;">Main engine propellant: NTO/MMH<br /></span><span style="color: #222222;">Total spacecraft delta v: 323 m/s<br /></span><span style="color: #222222;">Power: fuel cells/batteries; 155.0 kWh total<br /></span><span style="color: #222222;"><a href="https://www.braeunig.us/space/specs/gemini.htm">https://www.braeunig.us/space/specs/gemini.htm</a></span></p><p> The payload to LEO also can be increased by weight optimizing the first stage. The stage is similar to the <a href="https://en.wikipedia.org/wiki/LGM-25C_Titan_II#Stage_I_airframe" target="_blank">first stage of the Titan II </a>that launched the Gemini capsule to space, except the Titan II's first stage dry mass was 6,000 kg less. Reducing the first stage dry mass input in the SilverbirdAstronautics.com payload estimator by 6,000 kg increases the payload to ca. 6,000 kg. </p><p><br /></p><p> Robert Clark</p><p><br /></p><p style="text-align: left;"><span style="background-color: white; color: #222222;"><span style="font-family: inherit;"><br /></span></span></p><p style="text-align: left;"><span style="background-color: white; color: #222222;"><span style="font-family: inherit;"> </span></span></p>Robert Clarkhttp://www.blogger.com/profile/16114043697010364282noreply@blogger.com0tag:blogger.com,1999:blog-7598615455712402973.post-67588613761861791962024-01-08T11:49:00.008-05:002024-01-09T11:24:20.325-05:00Towards advancing the SpaceX Starship to operational flight: SpaceX should lower the Raptor chamber pressure and thrust level.<p style="text-align: center;"> Copyright 2023 Robert Clark</p><p style="text-align: center;"><br /></p><p style="text-align: left;"> In the blog post, <a href="https://exoscientist.blogspot.com/2023/12/did-spacex-throttle-down-booster.html" target="_blank">"Did SpaceX throttle down the booster engines on the IFT-2 test launch to prevent engine failures?"</a>, I suggested that SpaceX was able to get the SuperHeavy booster to complete its portion of the ascent in the last test flight by throttling down the thrust on the Raptor engines to less than 75%, and that the Starship upper stage was not able to because its Raptors were run at ~90%.</p><p style="text-align: left;"> Reducing the throttle level reduces the chamber pressure also, from 300 bar to ~225 bar, allowing the Raptor to fire without leaks.</p><p style="text-align: left;"> But if SpaceX lowered the thrust level on the booster to prevent engine failures, why did they not also do this on the Starship upper stage? From the propellant level indicators SpaceX provided on the launch video page, we can estimate the remaining propellant on the Starship just prior to FTS as under 100 tons out of a max 1,200 tons. </p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj-VabWORSqcVkKeWUCzv2xREIvdsGx53NIGEijZ502OxigdV1fLxF1wvpM5DEqc_OWXVD9sqKcC_YAswb-Ap2SdrZLrtaP8U_FAgZyfu4DfxayS1IENUh1wXVyFhjaXK5MLgyg8pyz-DFwKt10jyGVgWl_nyeUk_Qxyu9gczKsDRpDwB2QZiiSn0vTNVY/s2160/IMG_0266.PNG" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1620" data-original-width="2160" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj-VabWORSqcVkKeWUCzv2xREIvdsGx53NIGEijZ502OxigdV1fLxF1wvpM5DEqc_OWXVD9sqKcC_YAswb-Ap2SdrZLrtaP8U_FAgZyfu4DfxayS1IENUh1wXVyFhjaXK5MLgyg8pyz-DFwKt10jyGVgWl_nyeUk_Qxyu9gczKsDRpDwB2QZiiSn0vTNVY/w640-h480/IMG_0266.PNG" width="640" /></a></div> (<a href="https://youtu.be/JL7bPFxQKgM?si=H-pPaSVv-wPpDGV2&t=514" target="_blank">The ship is not visible in this image because of its extreme distance just before it exploded</a>.)<p style="text-align: left;"> Then we can estimate if the engines were run at less than 75%, the remaining propellant would be in the range of 300 tons. This likely would have been too much SpaceX to reach its goal of getting the Starship to just under orbital velocity:</p><p style="text-align: left;"><span style="font-family: inherit;"><span face=""Noto Sans", Arial, sans-serif" style="background-color: white; color: #1c1c1c;">SpaceX Starship megarocket launches on 2nd-ever test flight, explodes in 'rapid unscheduled disassembly' (video) News.</span><br style="background-color: white; color: #1c1c1c;" /><span face=""Noto Sans", Arial, sans-serif" style="background-color: white; color: #1c1c1c;">By Josh Dinner published November 18, 2023</span><br style="background-color: white; color: #1c1c1c;" /><em class="_7s4syPYtk5hfUIjySXcRE" style="background-color: white; border: 0px; color: #1c1c1c; font-stretch: inherit; font-variant-east-asian: inherit; font-variant-numeric: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;">The spacecraft was never expected to reach full orbit around Earth, instead flying on a suborbital trajectory to splash down in the Pacific Ocean off the coast of Hawaii. "We're not targeting orbit today; we're targeting almost orbit," said Siva Bharadvaj, a SpaceX operations engineer, adding that the goal was to "get to a thrust profile similar to what we would need for orbit, but also energy level that the ship would need to dissipate for reentry."</em></span><br style="background-color: white; color: #1c1c1c; font-family: "Noto Sans", Arial, sans-serif; font-size: 14px;" /><a class="_3t5uN8xUmg0TOwRCOGQEcU" href="https://www.space.com/spacex-starship-second-test-flight-launch-explodes" rel="noopener nofollow ugc" style="background-color: white; border: 0px; font-family: "Noto Sans", Arial, sans-serif; font-size: 14px; font-stretch: inherit; font-variant-east-asian: inherit; font-variant-numeric: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;" target="_blank" waprocessedanchor="true">https://www.space.com/spacex-starship-second-test-flight-launch-explodes</a></p><p style="text-align: left;"> So what would be the payload possible if we ran both stages at ~75% thrust? A rough estimate would be at approx. 100 tons as a fully reusable launcher, instead of the 150 tons now. A problem with that is the estimated number of refuelings for the Starship HLS used as an lunar lander was perhaps 16. But if the max payload was only 100 tons, then the number of refuelings would rise to 24.</p><p style="text-align: left;"> The idea of using so many refuelings for a lunar landing mission has been controversial. Then we'll look at other approaches. Robert Zubrin has noted it can be done in a single launch by giving the SuperHeavy/Starship a small 3rd stage, a mini Starship. </p><p style="text-align: left;"> Elon Musk once suggested an expendable version of the Starship could have a 30 to 1 mass ratio:</p><p style="text-align: left;"><i style="background-color: white; caret-color: rgb(51, 51, 51); color: #111111; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif;"><span face=""Segoe UI","sans-serif"" lang="EN" style="color: #0f1419; font-size: 11.5pt;"><b>__________________________________________________________________</b></span></i></p><p style="text-align: left;"><a href="https://x.com/elonmusk/status/1111798912141017089?s=61" target="_blank"><b style="background-color: white; caret-color: rgb(51, 51, 51); color: #111111; font-family: inherit;"><span face=""Segoe UI","sans-serif"" style="color: #0f1419; font-size: 11.5pt;"><i style="color: #2288bb; text-decoration: none;"><span style="color: #0f1419;">Elon Musk</span></i> </span></b><i style="background-color: white; caret-color: rgb(51, 51, 51); color: #2288bb; font-family: "Times New Roman", serif; font-size: 11.5pt; text-decoration: none;"><span face=""Segoe UI", "sans-serif"" style="color: #536471;">@elonmusk</span></i></a></p><ul class="nova-legacy-e-list nova-legacy-e-list--size-m nova-legacy-e-list--type-inline nova-legacy-e-list--spacing-xl" style="background-color: white; caret-color: rgb(17, 17, 17); color: #111111; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px; line-height: 1; list-style: none; margin: 0px 0px 30px; padding: 0px; text-size-adjust: 100%;"><span style="font-family: inherit; font-size: medium;"><ul class="nova-legacy-e-list nova-legacy-e-list--size-m nova-legacy-e-list--type-inline nova-legacy-e-list--spacing-xl" style="line-height: 1; list-style: none; margin: 0px 0px 30px; padding: 0px; text-size-adjust: 100%;"><ul class="nova-legacy-e-list nova-legacy-e-list--size-m nova-legacy-e-list--type-inline nova-legacy-e-list--spacing-xl" style="caret-color: rgb(51, 51, 51); line-height: 1; list-style: none; margin: 0px 0px 30px; padding: 0px; text-size-adjust: 100%;"><p class="MsoNormal" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; line-height: normal; margin-bottom: 0in;"><i><span style="color: black; font-family: "Times New Roman", "serif"; font-size: 11.5pt;"><a href="https://twitter.com/elonmusk/status/1111798912141017089" style="color: #2288bb; text-decoration-line: none; text-decoration: none;"><span face=""Segoe UI", "sans-serif"" style="color: #536471;">Mar 29, 2019</span></a><o:p></o:p></span></i></p><p class="MsoNormal" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; line-height: 15pt; margin-bottom: 0in;"><span face=""Segoe UI","sans-serif"" style="color: #536471; font-size: 11.5pt;"><i>Replying to<o:p></o:p></i></span></p><p class="MsoNormal" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; line-height: 15pt; margin-bottom: 0in;"><i><span face=""Segoe UI","sans-serif"" style="color: #536471; font-size: 11.5pt;"><a href="https://twitter.com/Erdayastronaut" style="color: #2288bb; text-decoration-line: none; text-decoration: none;"><span style="color: #1d9bf0;">@Erdayastronaut</span></a> </span><span face=""Segoe UI","sans-serif"" style="color: #1d9bf0; font-size: 11.5pt;">and</span><span face=""Segoe UI","sans-serif"" style="color: #536471; font-size: 11.5pt;"> <a href="https://twitter.com/DiscoverMag" style="color: #2288bb; text-decoration-line: none; text-decoration: none;"><span style="color: #1d9bf0;">@DiscoverMag</span></a><o:p></o:p></span></i></p><p class="MsoNormal" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; line-height: 15pt; margin-bottom: 0in;"><i><span face=""Segoe UI","sans-serif"" lang="EN" style="color: #0f1419; font-size: 11.5pt;">Probably no fairing either & just 3 Raptor Vacuum engines. Mass ratio of ~30 (1200 tons full, 40 tons empty) with Isp of 380. Then drop a few dozen modified Starlink satellites from empty engine bays with ~1600 Isp, MR 2. Spread out, see what’s there. Not impossible.<br /><b>__________________________________________________________________</b></span></i></p></ul></ul></span></ul><p style="text-align: left;"> We'll explore this capability. We'll first look at a case where both the SuperHeavy and Starship are expendable stages. A stage generally gets better mass ratio scaled up, so to begin with we'll start off with an estimated mass ratio for the SuperHeavy as about 30 to 1 with the same propellant load as it is now of 3,400 tons but a dry mass of only 115 tons. </p><p style="text-align: left;"> But that 30 to 1 mass ratio of the Starship is with just 3 engines since an upper stage does not need enough thrust to lift off from the ground. The SuperHeavy scaled up then would only have 9 engines, but this would not be enough for liftoff. We'll take the number of engines on this version of the SuperHeavy to be again 33. Then we need an additional 24 engines. </p><p style="text-align: left;"> The thrust/weight ratio of the Raptor is about 140 to 1. Assuming we're reducing the operational thrust level of the Raptor to 75%, its thrust would be 0.75*230 tons-force = 172.5 tons-force. At a 140 to 1 T/W ratio its mass would be 1.2 tons. So the additional 24 engines needed would add 24*1.2 = 28.8 tons to the dry mass: 115 + 28.8 = 143.8 tons. Round it up to 150 tons with the additional plumbing and larger thrust structure required.</p><p style="text-align: left;"> However, with the lower sea level thrust of our 75%-throttle Raptors, the 2-stage SH/SS would have low T/W ratio. We'll also look at a case of adding small 3rd stage of size ~300 tons. Adding a ~300 ton 3rd stage reduces the T/W to barely above 1. Then it would be advisable to add 2 more Raptors to the booster, bringing it to 35. There should be sufficient room beneath the booster for an additional 2 Raptors. </p><p style="text-align: left;"> The total thrust of the SuperHeavy at sea level is now 35*172.5 = 5,950 tons-force, 58,400 kiloNewtons(kN). We'll use the SilverbirdAstronautics.com payload estimator. This takes the vacuum Isp and vacuum thrust as inputs even for first stage engines. For the lower chamber pressure, ~ 225 bar corresponding to the reduced thrust, we would also have lower vacuum Isp. Call it about that of the Raptor 1 so ~ 350s. Then the vacuum thrust for this version of the Raptor would be (350/327)*172.5 = 184.6 tons-force. For the 35 SuperHeavy engines that's 35*184.6 = 6,460 tons-force, 63,400 kN vacuum thrust. For the dry mass for the 35 engine stage we'll raise it to 152.4 tons.</p><p style="text-align: left;"> For the Starship upper stage, the Raptor Vacuum will still have a vacuum Isp of 380s. However, we are keeping 3 sea level Raptors and 3 vacuum Raptors. Then the average Isp for the upper stage will be 370s. The vacuum thrust calculates out to be 11,500 kN. </p><p style="text-align: left;"> With the 3 additional Raptor engines being vacuum engines the added weight will be higher than that of just 3 additional sea level engines. We'll take the dry mass of the new upper stage to be 45,000 kg.</p><p style="text-align: left;"> Then the input page to the SilverbirdAstronautics.com page looks like:</p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgkI3CoYRkVLY8jryUr3DyLL0RPwTd0BegKgWQGvQL_RqtrLf-BhIIzUjrOrIeUI0SdUqyYe05GhtQFVTYCGwlzHEnpoOsYeWJCayi-LynD_TnLg_H_vWiNxc6JDWCLwiq8379rIefC1yjI5vv92D0CT3Akomno-o2rGDVLPCYpvszhq-_5c6hf1LYT4t8/s685/New%20SH-SS-6R%20inputs.JPG" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="604" data-original-width="685" height="564" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgkI3CoYRkVLY8jryUr3DyLL0RPwTd0BegKgWQGvQL_RqtrLf-BhIIzUjrOrIeUI0SdUqyYe05GhtQFVTYCGwlzHEnpoOsYeWJCayi-LynD_TnLg_H_vWiNxc6JDWCLwiq8379rIefC1yjI5vv92D0CT3Akomno-o2rGDVLPCYpvszhq-_5c6hf1LYT4t8/w640-h564/New%20SH-SS-6R%20inputs.JPG" width="640" /></a></div><br /><div class="separator" style="clear: both; text-align: center;"><br /></div><p style="text-align: left;"> And the payload results are:</p><p style="text-align: left;"><br /></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj-TYyVzkHPAwpRDJWcV5N_3yOj1SQ7S8ZKC2MdnhSuMdHDvO8TnN916boMaOnEv7P_0n_U3NTQc46EwOBaydyLbjzF_ghyEP2SLaiYggxtvEpAdCWErhn74ALQwMsJBxpYQRHpnvSXICyfaPYoWouVurlkGXXiKwY4-CGHAJuUclsTcXMKjsIyLsbbr44/s761/New%20SH-SS-6R%20results.JPG" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="514" data-original-width="761" height="432" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj-TYyVzkHPAwpRDJWcV5N_3yOj1SQ7S8ZKC2MdnhSuMdHDvO8TnN916boMaOnEv7P_0n_U3NTQc46EwOBaydyLbjzF_ghyEP2SLaiYggxtvEpAdCWErhn74ALQwMsJBxpYQRHpnvSXICyfaPYoWouVurlkGXXiKwY4-CGHAJuUclsTcXMKjsIyLsbbr44/w640-h432/New%20SH-SS-6R%20results.JPG" width="640" /></a></div><br /><div class="separator" style="clear: both; text-align: center;"><br /></div><p></p><p style="text-align: left;"> The expendable payload value of 264 tons is more than the expendable payload of the current SH/SS of 250 tons even-though the new version would be at 75% thrust level. This surprising result must be due the greatly reduced dry mass of both stages. </p><p style="text-align: left;"> But even more surprising is the payload possible to translunar injection(TLI). In the SilverbirdAstronautics.com calculator this option is indicated by selecting "Escape Trajectory" for "Destination". In the "Hyperbolic, C3" field enter, -1.0. This number indicates how far beyond escape velocity the flight needs. In this case, it's negative since you don't quite have to get to escape velocity to reach the Moon. </p><p style="text-align: left;"> Then the estimated payload is:</p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhKjoPhNU1FTC2n6bq6H70Sreaj-Opj8Ei39kZCl-zOenrkxiEi-jCdCtTX7QwQGFuD4fVlOZyf0U2x3YJiE3-z8Uk8SDHuuBUqrfgSISbX-AFyDtW0_F1q4pXpBx-p0Ge37VlvpZQIq4gFzgwuEnvJY_U-HKcSHSnnTdTQIuAjuM067qXn5nNTMI-zx9g/s667/New%20SH-SS-6R%20TLI%20payload.JPG" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="454" data-original-width="667" height="436" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhKjoPhNU1FTC2n6bq6H70Sreaj-Opj8Ei39kZCl-zOenrkxiEi-jCdCtTX7QwQGFuD4fVlOZyf0U2x3YJiE3-z8Uk8SDHuuBUqrfgSISbX-AFyDtW0_F1q4pXpBx-p0Ge37VlvpZQIq4gFzgwuEnvJY_U-HKcSHSnnTdTQIuAjuM067qXn5nNTMI-zx9g/w640-h436/New%20SH-SS-6R%20TLI%20payload.JPG" width="640" /></a></div><br /><div class="separator" style="clear: both; text-align: center;"><br /></div><br /><p style="text-align: left;"> The payload would be ~75 tons sent to rendevous with the Moon.This is far beyond what Apollo at ~43 tons or SLS even in its later Block 2 version at ~46 tons to TLI could do as a single launch architecture. This would allow wide latitude in how you would design the in-space stages and lander to reach the surface of the Moon.</p><p style="text-align: left;"> <b>A Three-Stage SuperHeavy/Starship/mini-Starship.</b></p><p style="text-align: left;"><b> </b>A basic principle of spaceflight is high delta-v missions, such as missions to the Moon or Mars, can be done more efficiently with more stages. Robert Zubrin has proposed a "mini-Starship" as a 3rd stage for the SuperHeavy/Starship. He trenchantly observed, "The Starship is a reusable Saturn V. It is not a LEM". Addition of a 3-rd stage would allow even higher payload to the Moon. Say, the mass ratio of ~30 to 1 can be retained for the 3rd stage at ca. 300 propellant load and ca. 10 tons dry mass, using a single Raptor vacuum of 380s Isp and 1,900 kN vacuum thrust. This gives an input page result:</p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiEj-81tPSvPxE7F0xw7mxre5zkL3ieZsvo-Tb9xOPrkEaE0i_fgHbEIfash0apyNmMFHxsZYyobUXxJZCu4pblbwEuPm6maUKpqIz6dmpI62x2git5iy4I_9DybmCoW6eJlLzc9qNUJKDne9th9rROUV0PvzBH3p7NWEWvqrBsAaO6SyIfVTzXCP3ei_4/s677/New%20SH-SS-6R%203%20stage%20inputs.JPG" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="601" data-original-width="677" height="568" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiEj-81tPSvPxE7F0xw7mxre5zkL3ieZsvo-Tb9xOPrkEaE0i_fgHbEIfash0apyNmMFHxsZYyobUXxJZCu4pblbwEuPm6maUKpqIz6dmpI62x2git5iy4I_9DybmCoW6eJlLzc9qNUJKDne9th9rROUV0PvzBH3p7NWEWvqrBsAaO6SyIfVTzXCP3ei_4/w640-h568/New%20SH-SS-6R%203%20stage%20inputs.JPG" width="640" /></a></div><div class="separator" style="clear: both; text-align: center;"><br /></div><p style="text-align: left;"> Then the payload to TLI would be ~105 tons:</p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjAIbAjZfRKd-JeQvbvMqG1Bp7nnhVeq3PC7NxeaYGkvt87QSx-H6xW_P7DD7XnRuUXSPxVEilfhVK7WehrnvVlsV829q85DJOYkb4wW6UhibNcmMvUrLKoLlD1QdYbw-9A5WwyKOUbfSonwIQ_ttR48kEVdiDFcxcIO4-JsI8ssAJ0N60ksHiPhhe9lPo/s738/New%20SH-SS-6R%203-stage%20TLI%20payload.JPG" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="517" data-original-width="738" height="448" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjAIbAjZfRKd-JeQvbvMqG1Bp7nnhVeq3PC7NxeaYGkvt87QSx-H6xW_P7DD7XnRuUXSPxVEilfhVK7WehrnvVlsV829q85DJOYkb4wW6UhibNcmMvUrLKoLlD1QdYbw-9A5WwyKOUbfSonwIQ_ttR48kEVdiDFcxcIO4-JsI8ssAJ0N60ksHiPhhe9lPo/w640-h448/New%20SH-SS-6R%203-stage%20TLI%20payload.JPG" width="640" /></a></div><br /><div class="separator" style="clear: both; text-align: center;"><br /></div><p style="text-align: left;"> This is regarding the SH/SS/mini-SS as a launcher analogous to the 3-stage Saturn V for the Apollo missions. This would require additional in-space stage(s) for doing the landing. However, the payload to TLI is so high this mini-Starship could itself serve as the lander for a round-trip mission to the Moon's surface with a capsule or habitat of ~15 tons mass. This is a mass 50% higher than the mass of the Orion capsule that could be carried not just to a lunar orbit planned for Orion, but all the way to the lunar surface and back to Earth again.</p><p style="text-align: left;"> <b>Flights to Mars.</b></p><p style="text-align: left;"> Addition of a third stage also allows more efficient flights to Mars in a single launch. This graphic gives the C3 needed for flights to the planets:</p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgcuN_ZOVwyf9ix1UtgCiLc3WzogIPachs2S11IwQ8JSJT-cQ_Y0snwjPhF_H-7wFk0pSm-u4aVyaUvqegHxFpdLzqiyQ0LjFdb74fA1pg1jAFuOMBEq7N9MN0XWniHPrHxrAMHbtiibsfdPGDiO973lh_Gh2OhE59avSdPZ_nxgkSr7IkZfifrZDraC0I/s547/C3%20lunar%20Mars.JPG" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="415" data-original-width="547" height="486" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgcuN_ZOVwyf9ix1UtgCiLc3WzogIPachs2S11IwQ8JSJT-cQ_Y0snwjPhF_H-7wFk0pSm-u4aVyaUvqegHxFpdLzqiyQ0LjFdb74fA1pg1jAFuOMBEq7N9MN0XWniHPrHxrAMHbtiibsfdPGDiO973lh_Gh2OhE59avSdPZ_nxgkSr7IkZfifrZDraC0I/w640-h486/C3%20lunar%20Mars.JPG" width="640" /></a></div><br /><p style="text-align: left;"> For Mars it is about 14 km2
/s2. The TMI payload to Mars is then:</p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgFb2fWhRM_HfL0sVWyKIA9g1dudVxDDLKTb9aYFzcIo92-MBRFWAtYAMT7X7IQZU_nRiTXiiWkAqVmJX64rxJ2VtUOhaVZGbKYNmrwSWHQxd1JggAwYliv1FIu1wNGUtoPllDVi6dDMqXysMneuPBDVzCDihDCb3mcy9tQDvNTvUwKipl2t93s7mpkRCw/s735/New%20SH-SS%206R%203%20stage%20Mars%20payload.JPG" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="453" data-original-width="735" height="394" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgFb2fWhRM_HfL0sVWyKIA9g1dudVxDDLKTb9aYFzcIo92-MBRFWAtYAMT7X7IQZU_nRiTXiiWkAqVmJX64rxJ2VtUOhaVZGbKYNmrwSWHQxd1JggAwYliv1FIu1wNGUtoPllDVi6dDMqXysMneuPBDVzCDihDCb3mcy9tQDvNTvUwKipl2t93s7mpkRCw/w640-h394/New%20SH-SS%206R%203%20stage%20Mars%20payload.JPG" width="640" /></a></div><div class="separator" style="clear: both; text-align: center;"><br /></div><p style="text-align: left;"> A payload of 86 tons sent towards Mars for trans-Mars injection(TMI) as a single flight architecture.</p><p style="text-align: left;"> These are for expendable versions of SuperHeavy/Starship. Elon Musk has estimated the cost of the SH/SS as in the range <a href="https://www.inc.com/jason-aten/spacex-just-blew-up-a-200-million-rocket-elon-musks-response-was-a-brilliant-example-of-emotional-intelligence.html#:~:text=What%20I%20do%20know%20is,his%20showmanship%20and%20brash%20style." target="_blank">$100 million to $200 million</a>. Even as expendable this is a greatly reduced cost than the SLS cost of $4 billion per flight.</p><p style="text-align: left;"><b>Estimates of Reusable Payloads.</b></p><p style="text-align: left;"> The reduction of cost of a flight to the Moon and Mars to only a couple of hundred million dollars rather than multi-billions makes the expendable versions worthwhile. But SpaceX is committed to reusability. </p><p style="text-align: left;"> Elon has said full reusability would lose 40 to 50% off payload. And even the reusability only for the first stage loses a quite significant 30% from the payload. These are from using powered boost back approach to landing. The propellant that must be kept on reserve, unused during the ascent for the boost back and landing is in the range of 7%. For the 3,400 ton prop load SuperHeavy this ~240 tons. This is doubly disadvantageous for payload in that not only can this prop not be used during flight to orbit but it also acts like additional dead-weight that must be carried in flight.</p><p style="text-align: left;"> Elon Musk has said powered, vertical landing is preferred over horizontal, winged landing because it can be used on airless or low atmospheric worlds such as the Moon and Mars. However, SpaceX needs to do a trade study to see which method results in the least payload lost. Wings typically take up about 5 to 10% of the gross weight of an aircraft. For a vertical launch rocket using non-lifting trajectory on ascent to orbit, this 5 to 10% would only have to be of the <i>dry weight</i> of the craft since aerodynamic lift would be used only during return when the stage is nearly empty. </p><p style="text-align: left;"> So for the SuperHeavy the added weight of the wings would only have to be 7.5 to 15 tons compared to the 240 tons needed for the vertical landing method. Actually, it likely can be even smaller than the 5%. For one thing rather than using large wings such as used on the Shuttle. It could use short, stubby wings instead. The large wings of the shuttle were due to competing requirements by NASA and the Air Force for where the Shuttle should be able to land. </p><p style="text-align: left;">Examples of how they could look instead might be those of the X-37 and of the Skylon:</p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiFZzP4aLZQFhTxM4o6xXJ1Di6nVKiZs3FvlB9NDouAXNgh8H2BYWGOL6vhkMjy4DqR0yfEf49I0zFh51Gas4wB_kd8Cw4IGcAH0wg1R0CbXNY5K3AoYuh5Mpfs2D5Qtyy06ARpRN9UD1cnaF-Wtfb2uaP4yvCNoA96jlnojrMVKAoix1F3ZkMITi7V4HA/s800/DrywoonUcAA1uel.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="479" data-original-width="800" height="384" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiFZzP4aLZQFhTxM4o6xXJ1Di6nVKiZs3FvlB9NDouAXNgh8H2BYWGOL6vhkMjy4DqR0yfEf49I0zFh51Gas4wB_kd8Cw4IGcAH0wg1R0CbXNY5K3AoYuh5Mpfs2D5Qtyy06ARpRN9UD1cnaF-Wtfb2uaP4yvCNoA96jlnojrMVKAoix1F3ZkMITi7V4HA/w640-h384/DrywoonUcAA1uel.jpg" width="640" /></a></div><br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhDdSEbk4At85t6cUJ10qOXZ5ewip0VlOTbm0aXqo7C5jJP_9tychGU74WZ99pgLilwRP00-IEOMGz0oMlx546pXx_eA7t3BmMYH1rM4tPx2ZLQkP2gyjTpMjoikhXh_eDGy_iOyc_ts0QpZWmC4gBPAY0W1X9AWxgpltbEwwpd2ou5w8pbANVBBaDDoTk/s650/hjRe3vjmGbgzWDSTqMvvDW-650-80.jpg.webp" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="435" data-original-width="650" height="428" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhDdSEbk4At85t6cUJ10qOXZ5ewip0VlOTbm0aXqo7C5jJP_9tychGU74WZ99pgLilwRP00-IEOMGz0oMlx546pXx_eA7t3BmMYH1rM4tPx2ZLQkP2gyjTpMjoikhXh_eDGy_iOyc_ts0QpZWmC4gBPAY0W1X9AWxgpltbEwwpd2ou5w8pbANVBBaDDoTk/w640-h428/hjRe3vjmGbgzWDSTqMvvDW-650-80.jpg.webp" width="640" /></a></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><div class="separator" style="clear: both; text-align: left;"><span style="font-family: inherit;"> For the Skylon by using carbon-fiber the wing weight was only 2% of the landed weight. This is 2% of the full gross weight because it used a horizontal liftoff. But since the Starship will be using a vertical liftoff and non-lifting trajectory, the wings only have to support the weight of the vehicle on return, so that 2% only has to be calculated on just the dry weight. The </span>specialty <span style="font-family: inherit;">high strength stainless steel used on the Starship might be preferred for the wings as well since it would have about the same strength but have reduced thermal shielding requirements. </span></div><div class="separator" style="clear: both; text-align: left;"><span style="font-family: inherit;"><br /></span></div><div class="separator" style="clear: both; text-align: left;"><span style="font-family: inherit;"> The landing gear weight can be taken as only 3%:</span></div><div class="separator" style="clear: both; text-align: left;"><span style="font-family: inherit;"><br /></span></div><div class="separator" style="clear: both; text-align: left;"><span style="font-family: inherit;"><a href="https://yarchive.net/space/launchers/landing_gear_weight.html">https://yarchive.net/space/launchers/landing_gear_weight.html</a></span></div><div class="separator" style="clear: both; text-align: left;"><span style="font-family: inherit;"><br /></span></div><div class="separator" style="clear: both; text-align: left;"><span style="font-family: inherit;"> This likely can be reduced by half to ~1.5% by carbon-fiber or the specialty steel used on the Starship.</span></div><div class="separator" style="clear: both; text-align: left;"><span style="font-family: inherit;"><br /></span></div><div class="separator" style="clear: both; text-align: left;"><span style="font-family: inherit;"> Finally, the thermal protection such as SpaceX’s PICA-X might only add on additional 8% of the dry weight.</span></div><div class="separator" style="clear: both; text-align: left;"><span style="font-family: inherit;"><br /></span></div><div class="separator" style="clear: both; text-align: left;"><span style="font-family: inherit;"> So these extra systems required for reusability will only add a proportionally small amount to the dry mass, and so subtract only a proportionally small amount from the payload.</span></div><div class="separator" style="clear: both; text-align: left;"><span style="font-family: inherit;"><br /></span></div><div class="separator" style="clear: both; text-align: left;"><span style="font-family: inherit;"> </span></div><div class="separator" style="clear: both; text-align: left;"><span style="font-family: inherit;"><br /></span></div><div class="separator" style="clear: both; text-align: left;"><span style="font-family: inherit;"> Bob Clark</span></div><div class="separator" style="clear: both; text-align: left;"><br /></div></div>Robert Clarkhttp://www.blogger.com/profile/16114043697010364282noreply@blogger.com4tag:blogger.com,1999:blog-7598615455712402973.post-77842706541030936032023-12-28T15:50:00.001-05:002023-12-28T16:00:52.588-05:00SpaceX should withdraw its application for the Starship as an Artemis lunar lander, Page 2: The Raptor is an unreliable engine.<p style="text-align: center;"> <i>Copyright 2023 Robert Clark</i></p><p style="text-align: center;"><i><br /></i></p><p style="text-align: left;"> I had earlier argued that SpaceX should withdraw the Starship as a lunar lander. The primary basis for this was for safety of the surrounding population in case of an explosion on launch, <u><a href="https://exoscientist.blogspot.com/2023/08/spacex-should-withdraw-its-application.html" target="_blank">SpaceX should withdraw its application for the Starship as an Artemis lunar lander.</a></u></p><p style="text-align: left;"> However, an additional reason why the Starship should not be used for a lunar lander is for safety of the crew. In the blog post, <u><a href="https://exoscientist.blogspot.com/2023/12/did-spacex-throttle-down-booster.html" target="_blank">Did SpaceX throttle down the booster engines on the IFT-2 test launch to prevent engine failures?</a>,</u> I noted two separate methods of calculation suggest the SuperHeavy booster was throttled down to <75%. I also suggested the Starship upper stage was fired at ~90%. Given this difference in thrust power levels, I suggested the booster completed its portion of the ascent because it was throttled down and the upper stage did not because it was at close to full thrust. </p><p style="text-align: left;"> Even though the booster engines successfully fired during the ascent, the booster exploded during the attempted return. One explanation offered was the engines were damaged by fuel slosh during flip of the booster. However, it should be noted the Starship during tests of the landing procedure, that at least one Raptor always leaked fuel and caught fire.</p><div class="separator" style="clear: both; text-align: center;"><iframe allowfullscreen="" class="BLOG_video_class" height="266" src="https://www.youtube.com/embed/dbPw9LCpLzw" width="320" youtube-src-id="dbPw9LCpLzw"></iframe></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: left;"><div class="separator" style="clear: both;"><br /></div><div class="separator" style="clear: both;"> Note even in the last two shown here, SN10 and SN15, there were engine fires on landing. For SN10 the engine fire led to the vehicle exploding a few minutes after landing. For SN15 the fire was extinguished before it caused an explosion. SN15 was called a “successful” landing test because it did not explode. But that a Raptor still caught fire during this test gives further evidence the Raptor is still not a reliable engine. </div><div class="separator" style="clear: both;"><br /></div><div class="separator" style="clear: both;"> And SN11 experienced a catastrophic explosion after a fuel leak and engine fire: </div></div><br /><div class="separator" style="clear: both; text-align: center;"><iframe allowfullscreen="" class="BLOG_video_class" height="266" src="https://www.youtube.com/embed/uJGmwqjm-9k" width="320" youtube-src-id="uJGmwqjm-9k"></iframe></div><br /><p style="text-align: left;"> Since relighting the Raptors in flight always resulted in an engine fire, that is the most likely explanation for the IFT-2 booster explosion as well.</p><p style="text-align: left;"><b>SpaceX Misleadingly Characterizes Raptor's Qualification for Flight.</b></p><p style="text-align: left;"> SpaceX has been using the term "full duration" for their Raptor static fire tests when they might only last 5 seconds. In the rest of the industry other than SpaceX, a full duration static test means firing for the full duration of an actual launch. </p><div class="css-175oi2r r-18u37iz" style="align-items: stretch; border: 0px solid black; box-sizing: border-box; display: flex; flex-basis: auto; flex-direction: row; flex-shrink: 0; list-style: none; margin: 0px; min-height: 0px; min-width: 0px; padding: 0px; position: relative; z-index: 0;"><div class="css-175oi2r r-1iusvr4 r-16y2uox r-1777fci" style="align-items: stretch; border: 0px solid black; box-sizing: border-box; display: flex; flex-direction: column; flex: 1 0 0px; justify-content: center; list-style: none; margin: 0px; min-height: 0px; min-width: 0px; padding: 0px; position: relative; z-index: 0;"><div class="css-175oi2r r-zl2h9q" style="align-items: stretch; border: 0px solid black; box-sizing: border-box; display: flex; flex-basis: auto; flex-direction: column; flex-shrink: 0; list-style: none; margin: 0px 0px 2px; min-height: 0px; min-width: 0px; 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box-sizing: border-box; color: #0f1419; display: inline; font-family: TwitterChirp, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif; font-size: 17px; font-stretch: normal; font-variant-east-asian: normal; font-variant-numeric: normal; line-height: 24px; list-style: none; margin: 0px; min-width: 0px; overflow-wrap: break-word; padding: 0px; position: relative; text-align: inherit; text-overflow: unset; white-space: pre-wrap;"><i><span class="css-1qaijid r-bcqeeo r-qvutc0 r-poiln3" style="background-color: white; border: 0px solid black; box-sizing: border-box; display: inline; font-stretch: inherit; font-variant-east-asian: inherit; font-variant-numeric: inherit; line-height: inherit; list-style: none; margin: 0px; min-width: 0px; overflow-wrap: break-word; padding: 0px; text-overflow: unset;">280 seconds of glorious hot fire! </span><img alt="🔥" class="r-4qtqp9 r-dflpy8 r-zw8f10 r-sjv1od r-10akycc r-h9hxbl" draggable="false" src="https://abs-0.twimg.com/emoji/v2/svg/1f525.svg" style="background-color: white; display: inline-block; height: 1.2em; margin-left: 0.075em; margin-right: 0.075em; vertical-align: -20%; width: 1.2em;" title="Fire" /><span class="css-1qaijid r-bcqeeo r-qvutc0 r-poiln3" style="background-color: white; border: 0px solid black; box-sizing: border-box; display: inline; font-stretch: inherit; font-variant-east-asian: inherit; font-variant-numeric: inherit; line-height: inherit; list-style: none; margin: 0px; min-width: 0px; overflow-wrap: break-word; padding: 0px; text-overflow: unset;">
We are incredibly proud to be the 1st private company in </span><span class="r-18u37iz" style="background-color: white; flex-direction: row;"><a class="css-1qaijid r-bcqeeo r-qvutc0 r-poiln3 r-1loqt21" dir="ltr" href="https://twitter.com/hashtag/Europe?src=hashtag_click" role="link" style="background-color: rgba(0, 0, 0, 0); border: 0px solid black; box-sizing: border-box; color: #1d9bf0; cursor: pointer; display: inline; font-family: inherit; font-size: inherit; font-stretch: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; list-style: none; margin: 0px; min-width: 0px; overflow-wrap: break-word; padding: 0px; text-align: inherit; text-decoration-line: none; text-overflow: unset; white-space: inherit;">#Europe</a></span><span class="css-1qaijid r-bcqeeo r-qvutc0 r-poiln3" style="background-color: white; border: 0px solid black; box-sizing: border-box; display: inline; font-stretch: inherit; font-variant-east-asian: inherit; font-variant-numeric: inherit; line-height: inherit; list-style: none; margin: 0px; min-width: 0px; overflow-wrap: break-word; padding: 0px; text-overflow: unset;"> (</span><img alt="🤯" class="r-4qtqp9 r-dflpy8 r-zw8f10 r-sjv1od r-10akycc r-h9hxbl" draggable="false" src="https://abs-0.twimg.com/emoji/v2/svg/1f92f.svg" style="background-color: white; display: inline-block; height: 1.2em; margin-left: 0.075em; margin-right: 0.075em; vertical-align: -20%; width: 1.2em;" title="Exploding head" /><span class="css-1qaijid r-bcqeeo r-qvutc0 r-poiln3" style="background-color: white; border: 0px solid black; box-sizing: border-box; display: inline; font-stretch: inherit; font-variant-east-asian: inherit; font-variant-numeric: inherit; line-height: inherit; list-style: none; margin: 0px; min-width: 0px; overflow-wrap: break-word; padding: 0px; text-overflow: unset;">) to hot fire a staged-combustion upper stage for its full duration. This qualifies our upper stage and Helix engine for flight </span><img alt="🚀" class="r-4qtqp9 r-dflpy8 r-zw8f10 r-sjv1od r-10akycc r-h9hxbl" draggable="false" src="https://abs-0.twimg.com/emoji/v2/svg/1f680.svg" style="background-color: white; display: inline-block; height: 1.2em; margin-left: 0.075em; margin-right: 0.075em; vertical-align: -20%; width: 1.2em;" title="Rocket" /><span class="css-1qaijid r-bcqeeo r-qvutc0 r-poiln3" style="background-color: white; border: 0px solid black; box-sizing: border-box; display: inline; font-stretch: inherit; font-variant-east-asian: inherit; font-variant-numeric: inherit; line-height: inherit; list-style: none; margin: 0px; min-width: 0px; overflow-wrap: break-word; padding: 0px; text-overflow: unset;">
Enjoy the video and read more in our press release </span><img alt="➡️" class="r-4qtqp9 r-dflpy8 r-zw8f10 r-sjv1od r-10akycc r-h9hxbl" draggable="false" src="https://abs-0.twimg.com/emoji/v2/svg/27a1.svg" style="background-color: white; display: inline-block; height: 1.2em; margin-left: 0.075em; margin-right: 0.075em; vertical-align: -20%; width: 1.2em;" title="Rightwards arrow" /><span class="css-1qaijid r-bcqeeo r-qvutc0 r-poiln3" style="background-color: white; border: 0px solid black; box-sizing: border-box; display: inline; font-stretch: inherit; font-variant-east-asian: inherit; font-variant-numeric: inherit; line-height: inherit; list-style: none; margin: 0px; min-width: 0px; overflow-wrap: break-word; padding: 0px; text-overflow: unset;"> </span><a class="css-1qaijid r-bcqeeo r-qvutc0 r-poiln3 r-1loqt21" dir="ltr" href="https://t.co/3d78MPbbl1" original_target="https://bit.ly/3wjy2g4" rel="noopener noreferrer nofollow" role="link" style="background-color: white; border: 0px solid black; box-sizing: border-box; color: #1d9bf0; cursor: pointer; display: inline-block; font-stretch: inherit; font-variant-east-asian: inherit; font-variant-numeric: inherit; line-height: inherit; list-style: none; margin: 0px; min-width: 0px; overflow-wrap: break-word; padding: 0px; text-decoration-line: none; text-overflow: unset;" target="_blank" waprocessedanchor="true" waprocessedid="k866l"><span aria-hidden="true" class="css-1qaijid r-bcqeeo r-qvutc0 r-poiln3 r-hiw28u r-qvk6io" color="inherit" style="background-color: rgba(0, 0, 0, 0); border: 0px solid black; box-sizing: border-box; display: inline; font-family: inherit; font-size: 0px; font-stretch: inherit; font-variant: inherit; font-weight: inherit; line-height: 0px; list-style: none; margin: 0px; min-width: 0px; overflow-wrap: break-word; padding: 0px; text-align: inherit; text-overflow: unset; white-space: inherit;">https://</span>bit.ly/3WJY2G4</a></i><div mcafee_wa_ann="{"category":["it"],"flags":3,"key":"bit.ly","originalUrl":"https://bit.ly/3wjy2g4","scanner":"cache","timeCached":1703779597779,"trust":85,"ttl":2592000,"url":"bit.ly/3wjy2g4","originalScanner":"hti-url","dossierUrl":"https://bit.ly/3wjy2g4"}" style="background-color: white; cursor: default; display: inline-block; float: none; padding: 0px 0px 0px 4px; position: relative; top: 2px; z-index: 1;" waprocessedid="k866l"></div></div><div class="separator" style="clear: both; text-align: center;"><iframe allowfullscreen="" class="BLOG_video_class" height="266" src="https://www.youtube.com/embed/MXUR4m6SOB0" width="320" youtube-src-id="MXUR4m6SOB0"></iframe></div><div><br /></div><div style="text-align: center;"><span style="background-color: white; white-space: pre-wrap;"><span style="font-size: medium;"><a href="https://x.com/rfa_space/status/1664683388928655374?s=20">https://x.com/rfa_space/status/1664683388928655374?s=20</a></span></span></div><div style="text-align: center;"><span style="background-color: white; white-space: pre-wrap;"><span style="font-size: medium;"><br /></span></span></div><div style="text-align: left;"><span style="background-color: white; white-space: pre-wrap;"><span style="font-size: medium;">And for the four SSME's on the SLS core stage:</span></span></div><div style="text-align: left;"><span style="background-color: white; white-space: pre-wrap;"><span style="font-size: medium;"><br /></span></span></div><div style="text-align: left;"><span style="background-color: white; white-space: pre-wrap;"><div class="separator" style="clear: both; text-align: center;"><iframe allowfullscreen="" class="BLOG_video_class" height="266" src="https://www.youtube.com/embed/4JXs5y8AFiE" width="320" youtube-src-id="4JXs5y8AFiE"></iframe></div></span><div style="text-align: left;"><br /></div> SpaceX calling their 5 second long test fires "full duration" misleadingly gives the impression that is sufficient to qualify the engines for full mission flight time.</div><div style="text-align: left;"><br /></div><div style="text-align: left;"><b>No estimates for Raptor engine reliability publicly provided.</b></div></div></div></div><p style="text-align: left;"> For engines for a craft intended to carry astronauts and for which billions of dollars of public funds are earmarked there should be provided some indication about the safety and reliability of such engines. For instance this report provides estimates of the reliability of the different components of the SLS:</p><p>SLS-RPT-077<br />VERSION: 1<br />National Aeronautics and Space Administration<br />RELEASE DATE: MARCH 8, 2013<br />SPACE LAUNCH SYSTEM PROGRAM (SLSP)<br />RELIABILITY ALLOCATION REPORT</p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgET24c8HsAMnanjV2XdGLhZ5b5COs3mKyHKY5zGtiTAucVCSy_ZAVDBZkNmeUifpCCmeXt3c6toR5L8mh5eRySd4FG1M5q-axEtbb8xFeYNE7F7VjKRLLgoKE2t5XsuMEBRtH3qllXoiMB6hvMwda0OrEUI_uxaDms3PiD6e7rqBfZ_IjLhh3IxrXpRog/s776/SLS%20reliability%20allocation.JPG" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="548" data-original-width="776" height="453" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgET24c8HsAMnanjV2XdGLhZ5b5COs3mKyHKY5zGtiTAucVCSy_ZAVDBZkNmeUifpCCmeXt3c6toR5L8mh5eRySd4FG1M5q-axEtbb8xFeYNE7F7VjKRLLgoKE2t5XsuMEBRtH3qllXoiMB6hvMwda0OrEUI_uxaDms3PiD6e7rqBfZ_IjLhh3IxrXpRog/w640-h453/SLS%20reliability%20allocation.JPG" width="640" /></a></div><a href="https://foia.msfc.nasa.gov/sites/foia.msfc.nasa.gov/files/FOIA%20Docs/42/SLS-RPT-077_SLSP-Reliability-Allocation-Report.pdf">https://foia.msfc.nasa.gov/sites/foia.msfc.nasa.gov/files/FOIA%20Docs/42/SLS-RPT-077_SLSP-Reliability-Allocation-Report.pdf</a><br /><p> But no such estimates for the Raptor have been provided. That so many engines have consistently failed in actual flights suggest they have quite low reliability.</p><p> In the scenario of the Merlin engines used for crewed flight, over 80 missions of the Falcon 9 were successfully flown before the first crewed flight. That means over 800 successful firings of the Merlins during that time. And added on after that the many launches since then, over one thousand successful firings of the Merlins have been made.</p><p> Robert Clark</p>Robert Clarkhttp://www.blogger.com/profile/16114043697010364282noreply@blogger.com4tag:blogger.com,1999:blog-7598615455712402973.post-47208893183086920382023-12-15T11:16:00.005-05:002024-03-25T02:02:23.573-04:00Did SpaceX throttle down the booster engines on the IFT-2 test launch to prevent engine failures?<p style="text-align: center;"><i> Copyright 2023 Robert Clark</i></p><div style="animation-name: none; font-family: inherit; transition-property: none;"><div dir="auto" style="animation-name: none; font-family: inherit; transition-property: none;"><div class="x1iorvi4 x1pi30zi x1l90r2v x1swvt13" data-ad-comet-preview="message" data-ad-preview="message" id=":rc4:" style="animation-name: none; font-family: inherit; padding: 4px 16px 16px; transition-property: none;"><div class="x78zum5 xdt5ytf xz62fqu x16ldp7u" style="animation-name: none; display: flex; flex-direction: column; font-family: inherit; margin-bottom: -5px; margin-top: -5px; transition-property: none;"><div class="xu06os2 x1ok221b" style="animation-name: none; font-family: inherit; margin-bottom: 5px; margin-top: 5px; transition-property: none;"><span class="x193iq5w xeuugli x13faqbe x1vvkbs x1xmvt09 x1lliihq x1s928wv xhkezso x1gmr53x x1cpjm7i x1fgarty x1943h6x xudqn12 x3x7a5m x6prxxf xvq8zen xo1l8bm xzsf02u x1yc453h" color="var(--primary-text)" dir="auto" style="animation-name: none; display: block; font-family: inherit; line-height: 1.3333; max-width: 100%; min-width: 0px; overflow-wrap: break-word; transition-property: none; word-break: break-word;"><div class="xdj266r x11i5rnm xat24cr x1mh8g0r x1vvkbs x126k92a" style="animation-name: none; font-family: inherit; font-size: 0.9375rem; margin: 0px; overflow-wrap: break-word; transition-property: none; white-space: pre-wrap;"><div dir="auto" style="animation-name: none; font-family: inherit; transition-property: none;"> Given the Raptors repeated history of leaking fuel and catching fire I was surprised the booster was able to complete its portion of the ascent with no engine failures.</div></div><div class="x11i5rnm xat24cr x1mh8g0r x1vvkbs xtlvy1s x126k92a" style="animation-name: none; font-family: inherit; margin: 0.5em 0px 0px; overflow-wrap: break-word; transition-property: none; white-space: pre-wrap;"><div dir="auto" style="animation-name: none; font-family: inherit; font-size: 0.9375rem; transition-property: none;"> <u>Hypothesis</u>: the booster flew without engine failures because it throttled down to < 75%. The Starship had engine failures because it ran at ~90%, like the booster did on the first test flight with its multiple engine failures.</div><div dir="auto" style="animation-name: none; font-family: inherit; font-size: 0.9375rem; transition-property: none;"><br /></div><div dir="auto" style="animation-name: none; font-family: inherit; transition-property: none;"><b><span style="font-size: medium;">Throttle Down Calculated by Propellant vs. Time Graph.</span></b></div></div><div class="x11i5rnm xat24cr x1mh8g0r x1vvkbs xtlvy1s x126k92a" style="animation-name: none; font-family: inherit; font-size: 0.9375rem; margin: 0.5em 0px 0px; overflow-wrap: break-word; transition-property: none; white-space: pre-wrap;"><div dir="auto" style="animation-name: none; font-family: inherit; transition-property: none;">Two separate observers, <a href="https://www.reddit.com/r/SpaceXLounge/s/v1sJGP8ncx" target="_blank">u/jobo555</a> and <a href="https://x.com/space_josiah/status/1726731762347503745" target="_blank">@space_josiah</a> found fairly constant propellant flow rate, and therefore <span style="animation-name: none; font-family: inherit; transition-property: none;"><a style="animation-name: none; color: #385898; cursor: pointer; font-family: inherit; transition-property: none;" tabindex="-1"></a></span>throttle, before where the booster begins to prepare for stage separation. Rocket thrust is given by (thrust) = (exhaust speed)*(propellant flow rate). So can get degree of throttle by propellant flow rate.</div></div><div class="x11i5rnm xat24cr x1mh8g0r x1vvkbs xtlvy1s x126k92a" style="animation-name: none; font-family: inherit; font-size: 0.9375rem; margin: 0.5em 0px 0px; overflow-wrap: break-word; transition-property: none; white-space: pre-wrap;"><div dir="auto" style="animation-name: none; font-family: inherit; transition-property: none;"> The graphs give the percentage of propellant remaining vs time. From this we can calculate the percentage change rate as the slope. For the booster it’s about 0.5%/s, 0.005/s as a decimal. Then given the total propellant load of 3,400 tons, in absolute term that propellant flow rate is 17 tons per second.</div></div><div class="x11i5rnm xat24cr x1mh8g0r x1vvkbs xtlvy1s x126k92a" style="animation-name: none; font-family: inherit; font-size: 0.9375rem; margin: 0.5em 0px 0px; overflow-wrap: break-word; transition-property: none; white-space: pre-wrap;"><div dir="auto" style="animation-name: none; font-family: inherit; transition-property: none;"> But the full thrust propellant flow rate for each Raptor v2 can be calculated as:</div></div><div class="x11i5rnm xat24cr x1mh8g0r x1vvkbs xtlvy1s x126k92a" style="animation-name: none; font-family: inherit; font-size: 0.9375rem; margin: 0.5em 0px 0px; overflow-wrap: break-word; transition-property: none; white-space: pre-wrap;"><div dir="auto" style="animation-name: none; font-family: inherit; transition-property: none;">props flow rate = thrust/exhaust speed = 230,000*9.81/(327*9.81) = 700 kg/s. Then for all 33 engines on the booster that’s 33*700 kg/s = 23,100 kg/s, 23.1 tons/s. Then the throttle down for the booster amounted to: 17/23.1 = .736, less than 75%.</div></div><div class="x11i5rnm xat24cr x1mh8g0r x1vvkbs xtlvy1s x126k92a" style="animation-name: none; font-family: inherit; font-size: 0.9375rem; margin: 0.5em 0px 0px; overflow-wrap: break-word; transition-property: none; white-space: pre-wrap;"><div dir="auto" style="animation-name: none; font-family: inherit; transition-property: none;"> For the Starship, from the first image below, in its second graph we see from 4 minutes to 8 minutes, 240 seconds, the propellant level dropped from ~80% to ~5%, for a percentage rate drop of 75/240, 0.313%/s. Then the absolute flow rate for a 1,200 ton prop load is 3.756 tons per second. But for the 6 engines the flow rate at full thrust would be 6*700 = 4,200 kg/s, 4.2 tons/s. Then the throttle is .894, ~90%.</div></div><div class="x11i5rnm xat24cr x1mh8g0r x1vvkbs xtlvy1s x126k92a" style="animation-name: none; font-family: inherit; font-size: 0.9375rem; margin: 0.5em 0px 0px; overflow-wrap: break-word; transition-property: none; white-space: pre-wrap;"><div dir="auto" style="animation-name: none; font-family: inherit; transition-property: none;"> Note that throttling down to 75% also correspondingly drops the combustion chamber pressure from 300 bar to about 225 bar, allowing the Raptor to operate without leaks. </div></div><div class="x11i5rnm xat24cr x1mh8g0r x1vvkbs xtlvy1s x126k92a" style="animation-name: none; font-family: inherit; margin: 0.5em 0px 0px; overflow-wrap: break-word; transition-property: none; white-space: pre-wrap;"><div dir="auto" style="animation-name: none; font-family: inherit; font-size: 0.9375rem; transition-property: none;"> But this reduced thrust would also mean the SuperHeavy/Starship could carry less payload. I estimate a drop in payload to ca. 100 tons reusable. In such a scenario, the 16 refueling launches needed for a Starship HLS would be increased to 24 launches.</div><div dir="auto" style="animation-name: none; font-family: inherit; font-size: 0.9375rem; transition-property: none;"><br /></div><div class="separator" style="clear: both; font-size: 0.9375rem; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjbxbaZQqTJwWiO9kXeOs9mghkIYeEDiN-48WJ8zafK15qtZv9l7fyVCrceF3dmW_C1fYYVjV3DbyDzrlRSEFSmiL44ANsY1b3QqyxdCOkElf2h4BOgmb-oUyScnwJncXKnV4WgvXvAfHM2GPsIl_xQwSDjzMMU-4vLWwyN58OdJUOPukwKcHm10IY7ekE/s2288/SuperHeavy%20throtted%20down.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="640" data-original-width="2288" height="180" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjbxbaZQqTJwWiO9kXeOs9mghkIYeEDiN-48WJ8zafK15qtZv9l7fyVCrceF3dmW_C1fYYVjV3DbyDzrlRSEFSmiL44ANsY1b3QqyxdCOkElf2h4BOgmb-oUyScnwJncXKnV4WgvXvAfHM2GPsIl_xQwSDjzMMU-4vLWwyN58OdJUOPukwKcHm10IY7ekE/w640-h180/SuperHeavy%20throtted%20down.jpg" width="640" /></a></div><span style="font-size: 0.9375rem;"><br /></span><div dir="auto" style="animation-name: none; font-family: inherit; font-size: 0.9375rem; transition-property: none;"><br /></div><div dir="auto" style="animation-name: none; font-family: inherit; transition-property: none;"><b><span style="font-size: medium;">Throttle Down Calculated by Acceleration Graph.</span></b></div><div dir="auto" style="animation-name: none; font-family: inherit; font-size: 0.9375rem; transition-property: none;"> A completely separate argument allows us to conclude the thrust was throttled down to less than 75%. This observer <a href="https://x.com/meithan42/status/1727420650019807435" target="_blank">@meithan42</a> looked at the velocity and altitude data and derived the acceleration data.</div><div dir="auto" style="animation-name: none; font-family: inherit; font-size: 0.9375rem; transition-property: none;"><br /></div><div class="separator" style="clear: both; font-size: 0.9375rem; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg4jZFSCGdMh01sCoJDxFuSuvyy8_IeG7FqvQkDpn9vp-42oK7rAWrE8wut2Qk1JJUUk0X8tMkc-dxmzZVrn8qi6rBQIgTaF1ylC-tOixxFofth-QLvUlXbAnsDK4r-AYJSLzTjhOoOoqk03WjaQvtE0ht5-up6v_1AOEnFIOx7sEBsNZU-7DVxui4-omY/s2000/IFT-2%20acceleration%20graph.JPG" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1200" data-original-width="2000" height="384" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg4jZFSCGdMh01sCoJDxFuSuvyy8_IeG7FqvQkDpn9vp-42oK7rAWrE8wut2Qk1JJUUk0X8tMkc-dxmzZVrn8qi6rBQIgTaF1ylC-tOixxFofth-QLvUlXbAnsDK4r-AYJSLzTjhOoOoqk03WjaQvtE0ht5-up6v_1AOEnFIOx7sEBsNZU-7DVxui4-omY/w640-h384/IFT-2%20acceleration%20graph.JPG" width="640" /></a></div><span style="font-size: 0.9375rem;"><br /></span><div dir="auto" style="animation-name: none; font-family: inherit; font-size: 0.9375rem; transition-property: none;"> On the acceleration graph I marked where the horizontal acceleration visually appears about 10 m/s<sup>2</sup>. The vertical acceleration there visually appears as about 6 m/s<sup>2</sup>. Visually this occurs at about the 90 second point. </div><div dir="auto" style="animation-name: none; font-family: inherit; font-size: 0.9375rem; transition-property: none;"> Note that gravity subtracts ~10 <span style="font-family: inherit; font-size: 0.9375rem;">m/s</span><sup style="font-family: inherit;">2</sup><span style="font-family: inherit; font-size: 0.9375rem;"> from the vertical acceleration, the actual vertical acceleration produced by the engines thrust is about 16 </span><span style="font-family: inherit; font-size: 0.9375rem;">m/s</span><sup style="font-family: inherit;">2</sup><span style="font-family: inherit; font-size: 0.9375rem;">. Then the actual acceleration generated by the engines thrust is SQRT(10</span><sup style="font-family: inherit;">2</sup><span style="font-family: inherit; font-size: 0.9375rem;"> </span><span style="font-family: inherit; font-size: 0.9375rem;"> + 16</span><sup style="font-family: inherit;">2</sup><span style="font-family: inherit; font-size: 0.9375rem;">) = 18.87 </span><span style="font-family: inherit; font-size: 0.9375rem;">m/s</span><sup style="font-family: inherit;">2</sup><span style="font-family: inherit; font-size: 0.9375rem;"> . </span><span style="font-family: inherit; font-size: 0.9375rem;"> </span></div><div dir="auto" style="animation-name: none; font-family: inherit; font-size: 0.9375rem; transition-property: none;"><span style="font-family: inherit; font-size: 0.9375rem;"><br /></span></div><div dir="auto" style="animation-name: none; font-family: inherit; font-size: 0.9375rem; transition-property: none;"><span style="font-family: inherit; font-size: 0.9375rem;"> But now lets calculate the actual acceleration that should be produced by the engines assuming they were running at full throttle at the 90 second point. The thrust is, (thrust) = (exhaust speed) * (flow rate). Since we are near vacuum the Isp will be 363 s and the exhaust speed 363*9.81 = 3,560 m/s. Then the thrust at full throttle with a total prop flow rate of 23,000 kg/s, should be thrust = 3,560*23,000 = 81,880,000 N. </span></div><div dir="auto" style="animation-name: none; font-family: inherit; font-size: 0.9375rem; transition-property: none;"><span style="font-family: inherit; font-size: 0.9375rem;"><br /></span></div><div dir="auto" style="animation-name: none; font-family: inherit; font-size: 0.9375rem; transition-property: none;"><span style="font-family: inherit; font-size: 0.9375rem;"> We'll take the total mass of the rocket as 4,850,000 considering the tanks are filled slightly less than 100%. If the engines are at full throttle then the mass after 90 seconds is 4,850,000 - 90*23,000 = 2,780,000, and the actual acceleration generated would be 81,880,000/2,780,000 = 29.45 </span><span style="font-family: inherit; font-size: 0.9375rem;">m/s</span><sup style="font-family: inherit;">2</sup><span style="font-family: inherit; font-size: 0.9375rem;">. This is well beyond amount observed. </span></div><div dir="auto" style="animation-name: none; font-family: inherit; font-size: 0.9375rem; transition-property: none;"><span style="font-family: inherit; font-size: 0.9375rem;"><br /></span></div><div dir="auto" style="animation-name: none; font-family: inherit; font-size: 0.9375rem; transition-property: none;"><span style="font-family: inherit; font-size: 0.9375rem;"> In contrast, if we take the throttled down propellant flow rate as 17,000 kg/s, then we calculate the actual acceleration as:</span></div><div dir="auto" style="animation-name: none; font-family: inherit; font-size: 0.9375rem; transition-property: none;"><span style="font-family: inherit; font-size: 0.9375rem;"><br /></span></div><div dir="auto" style="animation-name: none; font-family: inherit; font-size: 0.9375rem; transition-property: none;"><span style="font-family: inherit; font-size: 0.9375rem;">363*9.81*17,000/(4,850,000 - 90*17,000) = 18.23 </span><span style="font-family: inherit; font-size: 0.9375rem;">m/s</span><sup style="font-family: inherit;">2</sup><span style="font-family: inherit; font-size: 0.9375rem;"> ,a value much closer to what is actually observed.</span></div><div dir="auto" style="animation-name: none; font-family: inherit; font-size: 0.9375rem; transition-property: none;"><span style="font-family: inherit; font-size: 0.9375rem;"><br /></span></div><div dir="auto" style="animation-name: none; font-family: inherit; font-size: 0.9375rem; transition-property: none;"><span style="font-family: inherit; font-size: 0.9375rem;"> Robert Clark</span></div></div></span></div></div></div></div></div><div style="animation-name: none; font-family: inherit; transition-property: none;"><div class="x168nmei x13lgxp2 x30kzoy x9jhf4c x6ikm8r x10wlt62" data-visualcompletion="ignore-dynamic" style="animation-name: none; border-radius: 0px 0px 8px 8px; font-family: inherit; overflow: hidden; transition-property: none;"><div style="animation-name: none; font-family: inherit; 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overflow: hidden; padding: 0px; position: relative; text-align: inherit; touch-action: manipulation; transition-property: none; user-select: none; z-index: 1;" tabindex="0"><div class="x9f619 x1ja2u2z xzpqnlu x1hyvwdk xjm9jq1 x6ikm8r x10wlt62 x10l6tqk x1i1rx1s" style="animation-name: none; box-sizing: border-box; clip-path: inset(50%); clip: rect(0px, 0px, 0px, 0px); font-family: inherit; height: 1px; overflow: hidden; position: absolute; transition-property: none; width: 1px; z-index: 0;">All reactions</div></div></span></div></div><div class="x9f619 x1n2onr6 x1ja2u2z x78zum5 x2lah0s x1qughib x1qjc9v5 xozqiw3 x1q0g3np xykv574 xbmpl8g x4cne27 xifccgj" style="align-items: stretch; animation-name: none; background-color: white; box-sizing: border-box; color: #65676b; display: flex; flex-flow: row nowrap; flex-shrink: 0; font-family: "Segoe UI Historic", "Segoe UI", Helvetica, Arial, sans-serif; justify-content: space-between; margin: -6px; position: relative; transition-property: none; z-index: 0;"></div></div></div></div></div></div></div></div>Robert Clarkhttp://www.blogger.com/profile/16114043697010364282noreply@blogger.com3tag:blogger.com,1999:blog-7598615455712402973.post-75455485462584813192023-10-25T15:43:00.003-04:002023-10-26T08:44:45.758-04:00Towards return of Europe to dominance of the launch market, Page 2: ESA needs an independent oversight agency.<p style="text-align: center;"> <span style="font-size: medium;">Copyright 2023 Robert Clark</span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> Recent news reports are the Ariane 6 will not be able to compete with the SpaceX Falcon 9, requiring an increase in subsidies to ArianeSpace resulting in a total of €350 million($380 million) per year:</span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;">Oops—It looks like the Ariane 6 rocket may not offer Europe any launch savings<br />Europe is subsidizing the launch of Internet satellites for Jeff Bezos.<br />ERIC BERGER - 10/12/2023, 11:26 AM<br /><a href="https://arstechnica.com/space/2023/10/oops-it-looks-like-the-ariane-6-rocket-may-not-offer-europe-any-launch-savings/"><span class="s3">https://arstechnica.com/space/2023/10/oops-it-looks-like-the-ariane-6-rocket-may-not-offer-europe-any-launch-savings/</span></a></span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> At a launch cadence of 6 launches per year this is a subsidy of nearly €60 million per launch. This means European tax payers will be paying over a billion euros for the contracted 18 launches on the Ariane 6 of the commercial venture the Kuiper satellite system of Jeff Bezos. In effect, European tax payers will be paying a billion euro subsidy to Jeff Bezos, the 2nd richest man in the world.</span></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span style="font-family: UICTFontTextStyleBody; font-size: x-large;"><br /></span></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span style="font-family: UICTFontTextStyleBody; font-size: x-large;">European Space Agency mulls extra Ariane 6 cash.</span></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;">BY <a href="https://www.politico.eu/author/caleb-larson/">CALEB LARSON</a></span></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;">OCTOBER 20, 2023 7:00 AM CET</span></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"><i>Strategic autonomy? Ariane 6 is in danger of turning into a fiasco for the ESA and France’s aerospace industry. Since being commissioned a decade ago, Ariane 6 <a href="https://www.politico.eu/article/europe-arianespace-rocket-space-race/">has been surpassed</a> by Elon Musk's SpaceX which has slashed the cost of launches with its partially reusable rocket technology. Because its predecessor Ariane 5, a super reliable commercial launcher, has already been retired, the European Commission is <a href="https://www.politico.eu/article/eu-elon-musk-replace-stalled-france-rocket-galileo-satellite/">even having to look</a> to SpaceX to get its satellites into orbit. That's exactly the kind of outsourcing Paris wants to avoid in its focus on building strategic autonomy.</i></span></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"><a href="https://www.politico.eu/article/european-space-agency-mulls-extra-ariane-6-rocket-cash-ask/">https://www.politico.eu/article/european-space-agency-mulls-extra-ariane-6-rocket-cash-ask/</a></span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> The fiasco has come to pass as Europe was forced to ask SpaceX to launch its vaunted Galileo GPS system on the Falcon 9, when it was intended to be launched on the Ariane 6:</span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><h2 style="text-align: left;"><span class="s1" style="font-family: UICTFontTextStyleBody;"><span style="font-weight: normal;">Europe Reluctantly Chooses SpaceX to Launch Its GPS Satellites.</span><span style="font-weight: 400;"><br /></span></span><span style="font-weight: normal;">Elon Musk's SpaceX is set to undertake its first launch of European satellites equipped with classified technology, specifically for the Galileo system.</span><span style="font-weight: 400;"><br /></span><a href="https://www.politico.eu/article/european-space-agency-mulls-extra-ariane-6-rocket-cash-ask/" style="font-family: UICTFontTextStyleBody; font-size: 23px; font-weight: normal;">https://www.politico.eu/article/european-space-agency-mulls-extra-ariane-6-rocket-cash-ask/</a></h2><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> Reports are the Vega-C is in a similar bad position with respect to the SpaceX Falcon 9 using rideshare for small payloads:</span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;">The Accidental Monopoly<br />How SpaceX became (just about) the only game in town<br />Jeff Foust<br />October 13, 2023<br /><i>SpaceX came with these Transporter missions, which have been really disrupting,” said Marino Fragnito, senior vice president of the Vega business unit at Arianespace. They have been a boon for smallsat developers, he acknowledged, offering low-cost access to space. “But at the same time, they have created a big problem in terms of the business case for all of the other players.”<br />He accused SpaceX of, in effect, predatory pricing, willing to lose money on Transporter missions to drive out competition. He noted that past Vega smallsat rideshare missions sold payloads at $25,000 per kilogram, whereas SpaceX has sold Transporter launches for one-fifth that price. “It’s crazy.”<br /></i><a href="https://spacenews.com/the-accidental-monopoly/"><span class="s3">https://spacenews.com/the-accidental-monopoly/</span></a></span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> This has been warned about for several years now:</span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;">Europe is starting to freak out about the launch dominance of SpaceX<br />The Falcon 9 has come to dominate commercial satellite launches.<br />ERIC BERGER - 3/22/2021, 11:24 AM<br /><i>However, there now appears to be increasing concern in Europe that the Ariane 6 and Vega-C rockets will not be competitive in the launch market of the near future. This is important, because while member states of the European Space Agency pay for development of the rockets, after reaching operational status, these launch programs are expected to become self-sufficient by attracting commercial satellite launches to help pay the bills.<br />Economic ministers in France and Italy have now concluded that the launch market has changed dramatically since 2014, when the Ariane 6 and Vega-C rockets were first designed. According to a report in Le Figaro newspaper, the ministers believe the ability of these new European rockets to compete for commercial launch contracts has significantly deteriorated since then.<br /></i><a href="https://arstechnica.com/science/2021/03/european-leaders-say-an-immediate-response-needed-to-the-rise-of-spacex/"><span class="s3">https://arstechnica.com/science/2021/03/european-leaders-say-an-immediate-response-needed-to-the-rise-of-spacex/</span></a></span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> European tax payers have the right to ask where the great expense of the Ariane 6 launcher is deriving from.</span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> No one in European space community is willing to ask or answer the question, “How much just to add a second Vulcain to the Ariane 5/6 core?”</span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> Then can someone, anyone in the European space community at least ask the question, “Does a single P120 solid rocket used for the Ariane 6 </span><span class="s3" style="font-family: UICTFontTextStyleBody; text-decoration: underline;">SRB</span><span class="s2" style="font-family: UICTFontTextStyleBody;">’s and the Vega-C first stage really cost €20 million?”<br /> “So that the two </span><span class="s3" style="font-family: UICTFontTextStyleBody; text-decoration: underline;">SRB</span><span class="s2" style="font-family: UICTFontTextStyleBody;">’s on the Ariane 62 cost €40 million, and the four on the Ariane 64 cost €80 million?”</span></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;">“So that out of the €115 recommended cost of the Ariane 64, €80 is just for the 4 solid side boosters?”</span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> It is important to recognize that the high price of the Ariane 6 and the Vega-C is coming solely from the large solid rockets they use.</span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> </span></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> It is common to think of solid side boosters as only adding a small amount to the price of a launcher, like with the small solids used on the Delta IV or Atlas V. But it is quite important to realize these are for </span><span class="s4" style="font-family: UICTFontTextStyleItalicBody; font-style: italic;">small</span><span class="s2" style="font-family: UICTFontTextStyleBody;"> side boosters that might be only ca. 1/10th the mass of the core. But for the Ariane 6 the large side boosters are the size of the core in mass, and for the Vega the large solid booster is the core.</span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> Then the concept of the low cost solid booster is no longer valid; indeed these solid rockets boosters are the cause of the high cost of these launchers. To give an illustrative example, imagine the size of the side boosters on the Delta IV and Atlas V were 10 times larger than they are. I think you can see that would mean their cost would be radically higher than they are now.</span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> So how bad is the pricing of the P120 solids used for the Ariane 6 solids and the Vega-C first stage? Three separate and independent arguments suggest the P120 solid booster costs ca. €20 million each.</span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> ArianeSpace suggested a price of €75 million for the Ariane 62 with two SRB's and €115 million for the Ariane 64 with four SRB's. The €40 million increase in price for the two additional SRB's on the Ariane 64 suggests that is the price for two, or €20 million each.</span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> A second argument for the high cost of the P120 solid rocket comes from comparing it to the cost of the GEM 63 SRB used on American launchers. The GEM 63 is estimated to cost in the range of $5 million to $7 million each. But the P120 is three times the size of the GEM 63. So based on that we expect the price to be in the range $15 million to $21 million each.</span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> A third argument comes from looking at the price of the Vega-C. It's in the range of €35 million. Elon Musk has estimated the first stage of the Falcon 9 is 60% of the price of the rocket, with the upper stage, fairing, and range costs making up the rest of the cost. </span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> The Vega-C is a 4-stager instead of the 2-stage Falcon 9, but the salient point still remains: the much larger size of the first stage than the other stages means it makes up the largest proportion of the cost. </span></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> Using the 60% Elon Musk estimate for the cost of the first stage would give a €21 million cost for the P120 first stage of the Vega-C.</span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> So there is abundant evidence the large side boosters used on the ArianeSpace rockets are quite expensive. But is there an alternative? Yes! The price of a single Vulcain is only €10 million. So eliminate the Ariane 6 SRB's entirely and use two to three Vulcains on the core instead. Not using the SRB's results in a greatly reduced price.</span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> For a two Vulcain Ariane 6 sans SRB's, use a smaller upper stage of ca. 10 ton size so it would be loftable by the two Vulcains. Then it could get ca. 12 tons to LEO.</span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> For a three Vulcain version without SRB's, it could get ca. 20 tons to LEO if you use a larger 40 ton to 50 ton upper stage made possible by the higher take-off thrust of the three Vulcains</span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> And for the replacement of the Vega-C? Use an approx. half-size Ariane 6 core and again a small ca. 10 ton upper stage so as to be loftable on a single Vulcain. This could get ca. 5 tons to LEO. This compared to the 2 tons LEO payload of the Vega-C. And it would be much cheaper than the Vega-C in not using the large SRB's.</span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> These LEO payload numbers can be easily confirmed by a rocket equation calculation.</span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> See discussion here:</span></p><p class="p5" style="-webkit-text-size-adjust: auto; font-size: 30px; font-stretch: normal; line-height: normal; margin: 0px 0px 4px; min-height: 37.8px; text-size-adjust: auto;"><span class="s5" style="font-family: UICTFontTextStyleBody; font-weight: bold;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;">Towards return of Europe to dominance of the launch market.</span></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s3" style="font-family: UICTFontTextStyleBody; text-decoration: underline;"><a href="https://exoscientist.blogspot.com/2023/10/towards-return-of-europe-to-dominance.html">https://exoscientist.blogspot.com/2023/10/towards-return-of-europe-to-dominance.html</a></span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> In looking at how it is determined the path ESA will take in selecting it’s future launchers, what missing is an <i>independent</i> review authority tasked with reviewing the finances and architectures chosen.</span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> This is what is done with NASA. NASA has an Office of Inspector General independent of the NASA leadership tasked with reviewing the finances and architectures for the space programs NASA selects. It serves as an <i>independent</i> oversight agency:</span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;">NASA should consider commercial alternatives to SLS, inspector general says<br />"NASA’s aspirational goal to achieve a cost savings of 50 percent is highly unrealistic."<br /><a href="https://arstechnica.com/author/ericberger/"><span class="s3">ERIC BERGER</span></a> - 10/13/2023, 3:07 PM<br /></span></p><div class="separator" style="clear: both; text-align: center;"><a href="https://cdn.arstechnica.net/wp-content/uploads/2023/10/SLS-costs.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="608" data-original-width="923" height="422" src="https://cdn.arstechnica.net/wp-content/uploads/2023/10/SLS-costs.jpg" width="640" /></a></div><a href="https://arstechnica.com/space/2023/10/inspector-general-on-nasas-plans-to-reduce-sls-costs-highly-unrealistic/" style="font-family: UICTFontTextStyleBody; font-size: 23px;"><span class="s3">https://arstechnica.com/space/2023/10/inspector-general-on-nasas-plans-to-reduce-sls-costs-highly-unrealistic/</span></a><br /><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-size-adjust: auto;"><br /></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-size-adjust: auto;"> Note the report breaks down the costs of the different components of the Artemis program. This is a necessity for analysing the cost effectiveness of the different parts of the program.</p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-size-adjust: auto;"><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> But such is lacking at ESA. For instance in that article “European Space Agency mulls extra Ariane 6 cash”, it is ESA that is effectively providing oversight of itself.</span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> With this arrangement ESA won’t question whether the architectures it chooses to begin with are the right ones or cost effective ones. Thus THE major question that must be asked remains unasked: is use of large solid side boosters cost effective? Would a cheaper architecture be obtained by using all-liquid propulsion?</span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> </span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; text-size-adjust: auto;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> Robert Clark</span></p>Robert Clarkhttp://www.blogger.com/profile/16114043697010364282noreply@blogger.com0tag:blogger.com,1999:blog-7598615455712402973.post-65719408768061606482023-10-09T11:22:00.000-04:002023-10-09T11:22:21.190-04:00Towards return of Europe to dominance of the launch market.<p style="text-align: center;"> Copyright 2023 Robert Clark</p><p style="text-align: center;"><br /></p><div class="ipsType_normal ipsType_richText ipsPadding_bottom ipsContained" data-controller="core.front.core.lightboxedImages" data-role="commentContent" style="-webkit-text-size-adjust: 100%; box-sizing: border-box; caret-color: rgb(45, 49, 52); color: #2d3134; display: table; font-family: lato, -apple-system, BlinkMacSystemFont, "segoe ui", Roboto, Helvetica, Arial, sans-serif, "apple color emoji", "segoe ui emoji", "segoe ui symbol"; font-size: 15px; line-height: 1.6; margin-top: 0px; overflow-wrap: break-word; overflow: auto hidden; padding-bottom: var(--sp-5) !important; table-layout: fixed; width: 692.390625px;"><p style="box-sizing: border-box;">ESA delays Vega C return to flight to late 2024<br style="box-sizing: border-box;" />Jeff Foust<br style="box-sizing: border-box;" />October 2, 2023<br style="box-sizing: border-box;" /><a href="https://spacenews.com/esa-delays-vega-c-return-to-flight-to-late-2024/" rel="external nofollow noopener" style="box-sizing: border-box; color: rgb( var(--theme-link) );" target="_blank">https://spacenews.com/esa-delays-vega-c-return-to-flight-to-late-2024/</a></p><p style="box-sizing: border-box;"> <em style="box-sizing: border-box;">Large</em> solids like on the Vega and as used on the Ariane 5 and 6 are not price competitive. Note this is true for <em style="box-sizing: border-box;">large</em> solids. Small solid side boosters like used on the Atlas V and Delta IV might be only 1/8th the size of the core stage, with a concomitant small increase in cost. But when the solids are large size such as being as much or more than the size of the core such as on the Ariane 5 and 6 or actually being the core like on the Vega, the bulk of the high expense of the rocket comes from the solids.</p><p style="box-sizing: border-box;">See discussion here:</p><p style="box-sizing: border-box;">Friday, May 19, 2023<br style="box-sizing: border-box;" />Who in European space will ask the impertinent question: How much would it cost to add a second Vulcain to the Ariane 5/6?<br style="box-sizing: border-box;" /><a href="https://exoscientist.blogspot.com/2023/05/who-in-european-space-will-ask.html" rel="external nofollow noopener" style="box-sizing: border-box; color: rgb( var(--theme-link) );" target="_blank">https://exoscientist.blogspot.com/2023/05/who-in-european-space-will-ask.html</a></p><p style="box-sizing: border-box;"> The cost of the two <abbr style="border-bottom-style: none; box-sizing: border-box; text-decoration: underline;" title="Solid fuel Rocket Booster">SRB</abbr>’s on the Ariane 62 cost €40 million out of the €75 million cost. So the rest of the two-stage rocket is only €35 million. Then those two large <abbr style="border-bottom-style: none; box-sizing: border-box; text-decoration: underline;" title="Solid fuel Rocket Booster">SRB</abbr>’s cost more than the entire rest of the rocket.</p><p style="box-sizing: border-box;"> As I argued there it would be cheaper just to put additional Vulcain(s) on the core and dispense with the<abbr style="border-bottom-style: none; box-sizing: border-box; text-decoration: underline;" title="Solid fuel Rocket Booster">SRB</abbr>’s entirely. An additional Vulcain would add €10 million to the price to bring it to €45 million.</p><p style="box-sizing: border-box;"> Using all liquid propulsion also results in a cheaper rocket than the Vega. To see what such an all-liquid replacement for the Vega would look like see discussion here:</p><p style="box-sizing: border-box;">Saturday, November 29, 2014<br style="box-sizing: border-box;" />A half-size Ariane for manned spaceflight.<br style="box-sizing: border-box;" /><a href="https://exoscientist.blogspot.com/2014/11/a-half-size-ariane-for-manned.html" rel="external nofollow noopener" style="box-sizing: border-box; color: rgb( var(--theme-link) );" target="_blank">https://exoscientist.blogspot.com/2014/11/a-half-size-ariane-for-manned.html</a></p><p style="box-sizing: border-box;"> By cutting down the core’s propellant size to a bit less than half and using a smaller ca. 10 ton upper stage, so it could be launched by a single Vulcain, you get an all-liquid two-stage rocket capable of about 5,000 kg to LEO. This compares to the 2,000 kg payload to LEO of the Vega.</p><p style="box-sizing: border-box;"> Quite important is the better cost per kilo for the all-liquid case. The Vega costs about €35 million for that 2,000 kg to LEO. But taking into account our all-liquid replacement to the Vega is half-size to the all-liquid Ariane 6, the cost conceivably could be in the range of only half the €45 million estimate of the all-liquid Ariane 6, so only ca. €22 million for a 5,000 kg to LEO launcher(!)</p><p style="box-sizing: border-box;"> And what about reusability? The Space Shuttle abundantly showed you don’t save on reusing solids. But SpaceX has abundantly showed you do save significantly on reusing a liquid-fueled booster. SpaceX reduces the price on the Falcon 9 from $60 million to $40 million, by reusing the booster only, so a price reduction of about one-third. If the same price reduction would apply for reusing the booster only for our half-sized Ariane, that would be a price of only €15 million for a 5,000 kg launcher(!)</p><p style="box-sizing: border-box;"> Europe could then dominate the market by offering rockets of differing sizes. For small payloads at 5,000 kg or less, a reused half-sized Ariane at €15 million. For larger payloads at ca. 10 tons, €30 million for the reused two-Vulcan Ariane. And for payloads in the Falcon 9 range of 20 tons, €36 million for the reused three-Vulcain Ariane 6.</p><p style="box-sizing: border-box;"> Bob Clark</p><p style="box-sizing: border-box; margin-bottom: 0px;"> </p></div><p><br class="Apple-interchange-newline" style="-webkit-text-size-adjust: auto;" /></p><div class="ipsItemControls" style="-webkit-tap-highlight-color: rgba(26, 26, 26, 0.3); -webkit-text-size-adjust: 100%; -webkit-text-stroke-width: 0px; align-items: center; border-top: 1px solid rgba( var(--theme-text_color),0.1 ); box-sizing: border-box; caret-color: rgb(0, 0, 0); color: rgb( var(--theme-text_light) ); display: flex; flex-wrap: wrap; font-family: lato, -apple-system, BlinkMacSystemFont, "segoe ui", Roboto, Helvetica, Arial, sans-serif, "apple color emoji", "segoe ui emoji", "segoe ui symbol"; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: 400; justify-content: flex-end; letter-spacing: normal; margin-top: auto; min-height: calc( 42px + ( var(--sp-2) * 2 ) ); orphans: auto; padding: var(--sp-2) var(--sp-5); text-align: start; text-decoration: none; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; width: 692.390625px; word-spacing: 0px;"><div class="ipsItemControls_right ipsClearfix" data-controller="core.front.core.reaction" style="box-sizing: border-box; flex-grow: 1; order: 2;"><div class="ipsReact ipsPos_right" style="align-items: center; box-sizing: border-box; display: flex; float: right; font-size: 12px; position: relative; z-index: 1900;"></div></div><ul class="ipsComment_controls ipsClearfix ipsItemControls_left" data-role="commentControls" style="box-sizing: border-box; flex-grow: 1; list-style: none; margin: 0px; order: 1; padding: 0px;"><li class="ipsJS_show" data-ipsquote-editor="topic_comment" data-ipsquote-target="#comment-4328247" style="box-sizing: border-box; display: inline-block; margin-right: 15px; vertical-align: middle;"><button class="ipsButton ipsButton_light ipsButton_verySmall ipsButton_narrow cMultiQuote ipsHide" data-action="multiQuoteComment" data-ipsquote-multiquote="" data-ipstooltip="" data-mqid="mq4328247" style="-webkit-user-select: none; appearance: button; background: rgb( var(--theme-light_button) ); border-radius: var(--button--radius); border: 1px solid transparent; box-sizing: border-box; color: rgb( var(--theme-light_button_font) ); cursor: pointer; display: inline-block; font-family: inherit; font-size: 14px; font-weight: 400; line-height: 26px; margin: 0px; max-width: 100%; overflow: hidden; padding: 0px 8px; text-align: center; text-decoration: none; text-overflow: ellipsis; text-shadow: none; text-transform: none; transition: all 0.1s linear 0s; vertical-align: middle; white-space: nowrap;" title="MultiQuote"><i class="fa fa-plus" style="-webkit-font-smoothing: antialiased; box-sizing: border-box; display: var(--fa-display, inline-block); font-family: var(--fa-style-family, "Font Awesome 6 Free"); font-size: inherit; font-stretch: normal; font-style: normal; font-variant-alternates: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-position: normal; font-weight: var(--fa-style, 900); line-height: 1; text-rendering: auto;"></i></button></li></ul></div>Robert Clarkhttp://www.blogger.com/profile/16114043697010364282noreply@blogger.com0tag:blogger.com,1999:blog-7598615455712402973.post-18420930450056336272023-09-14T10:57:00.004-04:002023-09-14T11:10:25.222-04:00Could ‘Oumuamua be a spent rocket stage?<p style="text-align: center;">Copyright 2023 Robert Clark</p><p style="text-align: left;"><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> I was interested to read of a supposed asteroid passing near Earth turning out to be a <a href="https://www.smithsonianmag.com/smart-news/astronomers-confirm-earths-newest-mini-moon-long-lost-rocket-180976461/" target="_blank">Centaur upper stage launched in 1966</a>. Because of the oddities of 'Oumuamua I wondered if the same could be true of 'Oumuamua as well.</span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> This occurred to me in reading Avi Loeb discussing 'Oumuamua in his book, <i><a href="https://www.amazon.com/Extraterrestrial-First-Intelligent-Beyond-Earth/dp/B08NFHWDZZ/" target="_blank">Extraterrestrial</a>. </i>He noted it had some small changing acceleration as if by outgassing. This would be the case if say a rocket stage developed a small hole and was outgassing the residual propellant left in the rocket after burnout even years later.</span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s2" style="font-family: UICTFontTextStyleBody;"><span style="font-size: 23px;"> Because the Centaur rocket stage is bright white I wondered if such a stage could be visible in asteroid surveys at such a distance as 'Oumuamua was seen, about 25 million km at closest approach to Earth. The Centaur is only 3 meters wide by 12 meters long. 'Oumuamua's cylindrical shape is also notable. Also notable is Spitzer space telescope could not detect it in the infrared.</span></span><span style="-webkit-text-size-adjust: auto; font-family: UICTFontTextStyleBody; font-size: 23px;"> The explanation given was a bright, i.e., reflective, object would heat up less, as it reflects much of the incident light, and so it was concluded Oumuamua was among the brightest of comets, assumed a comet because of the outgassing:</span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px;"><span class="s1" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><br /></p><div style="text-align: left;"><span style="font-size: medium;"><span class="s2" style="font-family: UICTFontTextStyleBody; text-decoration: underline;"><a href="https://solarsystem.nasa.gov/news/">NEWS</a></span><span class="s1" style="font-family: UICTFontTextStyleBody;"> | November 14, 2018<br /></span><span class="s1" style="font-family: UICTFontTextStyleBody;">NASA Learns More About Interstellar Visitor 'Oumuamua<br /></span><b style="box-sizing: border-box;">Small but Reflective<br /></b>The new study also suggests that 'Oumuamua may be up to 10 times more reflective than the comets that reside in our solar system — a surprising result, according to the paper's authors. Because infrared light is largely heat radiation produced by "warm" objects, it can be used to determine the temperature of a comet or asteroid; in turn, this can be used to determine the reflectivity of the object's surface — what scientists call albedo. Just as a dark T-shirt in sunlight heats up more quickly than a light one, an object with low reflectivity retains more heat than an object with high reflectivity. So a lower temperature means a higher albedo.<br /><a href="https://solarsystem.nasa.gov/news/759/nasa-learns-more-about-interstellar-visitor-oumuamua/" style="font-family: UICTFontTextStyleBody;">https://solarsystem.nasa.gov/news/759/nasa-learns-more-about-interstellar-visitor-oumuamua/</a></span></div><p class="p3" style="-webkit-text-size-adjust: auto; font-stretch: normal; line-height: normal; margin: 0px; text-align: left;"><span class="s2" style="font-family: UICTFontTextStyleBody; font-size: medium;"></span></p><div style="text-align: left;"><br /></div><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s2" style="font-family: UICTFontTextStyleBody;">But this would also be the case for a rocket stage painted white. Could the Centaur stage be visible at 25 million km distance by optical telescopes in being bright white?</span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> But there is also the issue of the fact 'Oumuamua was on a trajectory suggesting escape velocity. In Loebs book he discusses that asteroids can be ejected from their parent systems by interactions with other planets in their systems. Then what occurred to me is whether a spent rocket stage could reach solar system escape velocity by the slingshot effect used on some of our spacecraft to get additional speed.</span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> The possibility I was thinking about was the New Horizons mission. The spacecraft was given high initial speed by the stages sending it to the outer solar system but then additionally to that it was first directed towards Jupiter for a Jupiter slingshot effect.</span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> The NH spacecraft was given escape velocity at Jupiter after the gravity assist though actually aimed at Pluto.</span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> But suppose the Centaur, which was the upper stage to the Atlas V launcher, was also aimed at Jupiter in order to get NH there. There was an additional solid 3rd stage carrying the NH that got a slingshot effect from Jupiter. But it may have been the Centaur was aimed at Jupiter as well.</span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> Now suppose the Centaur on reaching Jupiter happened to be so aimed, unintentionally perhaps, that Jupiter's orbital motion around the Sun plus the slingshot effect would be sufficient to give the Centaur solar system escape velocity. </span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> But the aiming, whether unintentional or not, would have to be that rather than heading directly out of the solar system it would be headed towards the inner solar system.</span></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s2" style="font-family: UICTFontTextStyleBody;"><br /></span></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> But that’s where idea encounters problems. On calculating ‘Oumuamua’s trajectory backwards from its sighting near Earth, it appears to have had an incoming trajectory nearly perpendicular to the plane of the Solar System, at 123 degrees, <a href="https://i4is.org/oumuamua-some-more-strangeness/" target="_blank">as described by Adam Hibberd</a>. </span></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s2" style="font-family: UICTFontTextStyleBody;"><br /></span></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> It doesn’t seem possible that the Centaur after it’s gravity assist at Jupiter would come into the inner solar system at such a high angle. </span></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s2" style="font-family: UICTFontTextStyleBody;"><br /></span></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> Another problem is the closeness of the flyby’s of Mercury, Venus, and Earth by ‘Oumuamua. </span></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s2" style="font-family: UICTFontTextStyleBody;"><br /></span></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> See discussion here:</span></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s2" style="font-family: UICTFontTextStyleBody;"><br /></span></p><p class="p1" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s1" style="font-family: UICTFontTextStyleBody;">Further strangeness of 'Oumuamua.</span></p><p class="p1" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s1" style="font-family: UICTFontTextStyleBody;"><br /></span></p><p class="p1" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj02yLnPjSVdveJhIU5mlxTHfK8b-nRdmvKYiCZK8iVsnvqBOXyeKRc_w6o05uT6QV3IUy51Q5KOJBAQuj61Tb9fXp_rsVCjgz3J915kttnNtkpxEURUpm1sPHk03jKJaAfHEfPwhmpCV-6l0JcY5w8m4PFJv42K1f4M-g_MDqCIFhi6FHlNrn-Uh1fA-M/s800/C585E287-2122-41B3-BA24-80739102E74B.gif" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="473" data-original-width="800" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj02yLnPjSVdveJhIU5mlxTHfK8b-nRdmvKYiCZK8iVsnvqBOXyeKRc_w6o05uT6QV3IUy51Q5KOJBAQuj61Tb9fXp_rsVCjgz3J915kttnNtkpxEURUpm1sPHk03jKJaAfHEfPwhmpCV-6l0JcY5w8m4PFJv42K1f4M-g_MDqCIFhi6FHlNrn-Uh1fA-M/s16000/C585E287-2122-41B3-BA24-80739102E74B.gif" /></a></div><p></p><p class="p1" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s1" style="font-family: UICTFontTextStyleBody;"><br /></span></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s2" style="font-family: UICTFontTextStyleBody;"></span></p><p class="p1" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s1" style="font-family: UICTFontTextStyleBody;"><a href="http://exoscientist.blogspot.com/2023/09/further-strangeness-of-oumuamua.html">http://exoscientist.blogspot.com/2023/09/further-strangeness-of-oumuamua.html</a></span></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> It doesn’t seem reasonable that a rocket stage after doing a close flyby of Jupiter would subsequently also do ones of Mercury, Venus, and Earth. </span></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><br /></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s2" style="font-family: UICTFontTextStyleBody;"> So here’s another possibility. The Messenger spacecraft did multiple flybys of Mercury, Venus, and Earth on its trip to Mercury.</span></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s2" style="font-family: UICTFontTextStyleBody;"><br /></span></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgavOX0FKvXHq18XIF-DDqObE5eebNQMbcLU3invuc0EmaNX3rXcf2ociRl2sPbS7RX6KdILbBMkDxftDEgveGNXEfEhx8M558-e57LYiDaSLbEd_47UzPdPQjmFyry9X7gY9pB2XGM57X13EiYuJGYtKmwEDkGtvHhSPTyQn0LXwRTuqNUluXQ-JA_H64/s2160/11DADA11-8FEB-471A-93B6-DF3639206241.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1620" data-original-width="2160" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgavOX0FKvXHq18XIF-DDqObE5eebNQMbcLU3invuc0EmaNX3rXcf2ociRl2sPbS7RX6KdILbBMkDxftDEgveGNXEfEhx8M558-e57LYiDaSLbEd_47UzPdPQjmFyry9X7gY9pB2XGM57X13EiYuJGYtKmwEDkGtvHhSPTyQn0LXwRTuqNUluXQ-JA_H64/w640-h480/11DADA11-8FEB-471A-93B6-DF3639206241.png" width="640" /></a></div><br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhJUqWSNQ3qGF3C5hRat2fegPAahpAYOe4Gazj1mbeiUFNSVqkuGiX2RYdoSOW6wJXC2C1bBcxW_nOc0rBNp4_Q-O_eevHkNOdXC04CVwqRBi2kvrkKU7BXBhrHPU8BeACf4oMZDibuCIwJFuExz5Ni8ok3q6ZXeCdEEFsppl7y1mOigYQhwgXDoC4qDyc/s2160/CD6A58EC-57C6-4047-82C3-6981FEC0CA39.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1620" data-original-width="2160" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhJUqWSNQ3qGF3C5hRat2fegPAahpAYOe4Gazj1mbeiUFNSVqkuGiX2RYdoSOW6wJXC2C1bBcxW_nOc0rBNp4_Q-O_eevHkNOdXC04CVwqRBi2kvrkKU7BXBhrHPU8BeACf4oMZDibuCIwJFuExz5Ni8ok3q6ZXeCdEEFsppl7y1mOigYQhwgXDoC4qDyc/w640-h480/CD6A58EC-57C6-4047-82C3-6981FEC0CA39.png" width="640" /></a></div><br /><span class="s2" style="font-family: UICTFontTextStyleBody;"> <span style="font-size: large;">Then the upper stage that delivered Messenger on its trajectory to escape Earth may also have followed Messenger in its encounters with the inner solar system planets. The rocket that launched Messenger was the Delta II. </span></span><div><span class="s2" style="font-family: UICTFontTextStyleBody; font-size: large;"><br /></span></div><div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjnIPhwDaCDU2zgWJrrE9JXu6pMzp0VjN2OJ372JBhuh5_KUGYTxUTndYhdCNT9TvKHRohGbSpISwLMJfB5ofNyYCaptvPrg70gLUmGKRltUiqvpi8LkRyyFfDrvJuVvQ5M9E-LyztIro9EigNQFygfsjOto4KFd9XXCzejZMHfurlmNY-FdvNVnfOQ80A/s1920/963A1AB6-405A-42ED-B655-5451BD55B354.jpeg" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1920" data-original-width="1277" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjnIPhwDaCDU2zgWJrrE9JXu6pMzp0VjN2OJ372JBhuh5_KUGYTxUTndYhdCNT9TvKHRohGbSpISwLMJfB5ofNyYCaptvPrg70gLUmGKRltUiqvpi8LkRyyFfDrvJuVvQ5M9E-LyztIro9EigNQFygfsjOto4KFd9XXCzejZMHfurlmNY-FdvNVnfOQ80A/w426-h640/963A1AB6-405A-42ED-B655-5451BD55B354.jpeg" width="426" /></a></div><br /></div><div><span class="s2" style="font-family: UICTFontTextStyleBody; font-size: large;"> The upper stage had white fairings around it. But it seems likely these fairings are jettisoned like are the fairings making up the nose cone around the spacecraft. Then we’ll look at the second stage under the fairing.</span></div><div><br /></div><div><span style="font-family: UICTFontTextStyleBody; font-size: large;"> It was the Delta K stage. It was smaller than the Centaur stage at 2.4 meters wide and 6 meters long. There is also the issue of it, likely, not having bright white sides like the Centaur. So the question of whether it would be visible at the 25 million km closest approach of ‘Oumuamua becomes even more relevant. </span></div><div><span style="font-family: UICTFontTextStyleBody;"><br /></span></div><div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiIqL53l4Y8wQD_5GkD3KgUIU1f7tZFp4q3jdV33ytN6tYmMUoqIPXJo-L05IFadsSFFBvFShUlJsc3aEmLDkgB_NzfWbXvNlo5pdLRHNvFbRsFNXBGNgD0mgB0cwOV6bYldo68JCPYqzJcUzB3voz4fRP7vI9rl-XW0_LEMMY_WKwhKS8ZCGeNUhUI0Sk/s812/536B6AF8-3B4C-4B98-BFF6-EA6CBA5F0BFC.jpeg" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="812" data-original-width="540" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiIqL53l4Y8wQD_5GkD3KgUIU1f7tZFp4q3jdV33ytN6tYmMUoqIPXJo-L05IFadsSFFBvFShUlJsc3aEmLDkgB_NzfWbXvNlo5pdLRHNvFbRsFNXBGNgD0mgB0cwOV6bYldo68JCPYqzJcUzB3voz4fRP7vI9rl-XW0_LEMMY_WKwhKS8ZCGeNUhUI0Sk/w426-h640/536B6AF8-3B4C-4B98-BFF6-EA6CBA5F0BFC.jpeg" width="426" /></a></div><br /></div><div><h4 style="text-align: left;"><span style="font-family: UICTFontTextStyleBody; font-size: large;">The Color of ‘Oumuamua.</span></h4><div><span style="font-family: UICTFontTextStyleBody; font-size: large;"> The color of ‘Oumuamua has been described as red. This was taken as supportive of it being like the outer solar system objects that are also red. The inference was of it either acquiring a similar coating from long periods in the outer solar system or of it being a similar object in the outer stellar system of its origin.</span></div><div><span style="font-family: UICTFontTextStyleBody; font-size: large;"><br /></span></div><div><span style="font-family: UICTFontTextStyleBody; font-size: large;"> On the issue of ‘Oumuamua being uniformly red however there is some debate. At least one observational report describes it as “neutral” colored:</span></div><div><span style="font-family: UICTFontTextStyleBody; font-size: large;"><br /></span></div><div><p class="p1" style="-webkit-text-size-adjust: auto; font-stretch: normal; line-height: normal; margin: 0px 0px 3px;"><span class="s1" style="font-family: UICTFontTextStyleBody;"><span style="font-size: large;">Col-OSSOS: Colors of the Interstellar Planetesimal 1I/'Oumuamua</span></span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s2" style="font-family: UICTFontTextStyleBody;">Michele T. Bannister, et al.</span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s3" style="font-family: UICTFontTextStyleBody; text-decoration: underline;"><a href="https://iopscience.iop.org/journal/2041-8205">The Astrophysical Journal Letters</a></span><span class="s2" style="font-family: UICTFontTextStyleBody;">, <a href="https://iopscience.iop.org/volume/2041-8205/851"><span class="s3">Volume 851</span></a>, <a href="https://iopscience.iop.org/issue/2041-8205/851/2"><span class="s3">Number 2</span></a></span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s4" style="font-family: UICTFontTextStyleEmphasizedBody; font-weight: bold; text-decoration: underline;"><a href="https://iopscience.iop.org/collections/2041-8205_focus_issue_Focus_on_Oumuamua">Focus on the First Interstellar Small Body `Oumuamua</a></span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><i><span class="s2" style="font-family: UICTFontTextStyleBody;">The </span><span class="s5" style="font-family: UICTFontTextStyleItalicBody;">grJ</span><span class="s2" style="font-family: UICTFontTextStyleBody;"> colors of 1I/'Oumuamua are at the neutral end of the solar system populations (Figure </span><span class="s3" style="font-family: UICTFontTextStyleBody; text-decoration: underline;">3</span><span class="s2" style="font-family: UICTFontTextStyleBody;">). About 15% of the TNOs have colors consistent with 1I/'Oumuamua, all in dynamically excited populations. 1I/'Oumuamua's color is also consistent with that of the less-red Jupiter Trojans, which are P type (Emery et al. </span><span class="s3" style="font-family: UICTFontTextStyleBody; text-decoration: underline;">2011</span><span class="s2" style="font-family: UICTFontTextStyleBody;">), and with Bus & Binzel (</span><span class="s3" style="font-family: UICTFontTextStyleBody; text-decoration: underline;">2002a</span><span class="s2" style="font-family: UICTFontTextStyleBody;">) and DeMeo et al. (</span><span class="s3" style="font-family: UICTFontTextStyleBody; text-decoration: underline;">2009</span><span class="s2" style="font-family: UICTFontTextStyleBody;">) X type in the asteroids, which encompasses the Tholen (</span><span class="s3" style="font-family: UICTFontTextStyleBody; text-decoration: underline;">1984</span><span class="s2" style="font-family: UICTFontTextStyleBody;">) E, M, and P classifications. As its albedo is unknown, we do not describe 1I/'Oumuamua as consistent with the Tholen (</span><span class="s3" style="font-family: UICTFontTextStyleBody; text-decoration: underline;">1984</span><span class="s2" style="font-family: UICTFontTextStyleBody;">) P type.</span></i></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><i><span class="s2" style="font-family: UICTFontTextStyleBody;">Notably, 1I/'Oumuamua does not share the distinctly redder colors of the cold classical TNOs (Tegler et al. </span><span class="s3" style="font-family: UICTFontTextStyleBody; text-decoration: underline;">2003</span><span class="s2" style="font-family: UICTFontTextStyleBody;">; Pike et al. </span><span class="s3" style="font-family: UICTFontTextStyleBody; text-decoration: underline;">2017</span><span class="s2" style="font-family: UICTFontTextStyleBody;">), which may be on primordial orbits. Nor is its color among the red or "ultra-red" colors of the larger TNOs on orbits that cross or are well exterior to the heliopause (Sheppard </span><span class="s3" style="font-family: UICTFontTextStyleBody; text-decoration: underline;">2010</span><span class="s2" style="font-family: UICTFontTextStyleBody;">; Trujillo & Sheppard </span><span class="s3" style="font-family: UICTFontTextStyleBody; text-decoration: underline;">2014</span><span class="s2" style="font-family: UICTFontTextStyleBody;">; Bannister et al. </span><span class="s3" style="font-family: UICTFontTextStyleBody; text-decoration: underline;">2017</span><span class="s2" style="font-family: UICTFontTextStyleBody;">). The cause of ultra-red coloration of these TNOs is unknown, but has been attributed to long-term cosmic-ray alteration of organic-rich surfaces (Jewitt </span><span class="s3" style="font-family: UICTFontTextStyleBody; text-decoration: underline;">2002</span><span class="s2" style="font-family: UICTFontTextStyleBody;">), such as would be expected during the long duration of interstellar travel.</span></i></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s2" style="font-family: UICTFontTextStyleBody;"><a href="https://iopscience.iop.org/article/10.3847/2041-8213/aaa07c/meta">https://iopscience.iop.org/article/10.3847/2041-8213/aaa07c/meta</a></span></p><p class="p2" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><br /></p></div><div><span style="font-family: UICTFontTextStyleBody; font-size: large;"> Still the detected red coloration of some observations could be due to the red engine nozzle of the Delta K stage.</span></div><div><span style="font-family: UICTFontTextStyleBody; font-size: large;"><br /></span></div><div style="text-align: left;"><span style="font-family: UICTFontTextStyleBody; font-size: large;"><b> Escape velocity by gravity assists from inner planets? </b></span></div><div style="text-align: left;"><span style="font-family: UICTFontTextStyleBody; font-size: large;"><br /></span></div><div><span style="font-family: UICTFontTextStyleBody; font-size: large;"> The high velocity of ‘Oumuamua, well above Solar System escape velocity, has been much remarked upon, and it is the reason why it was taken to be an interstellar object. However, the New Horizons spacecraft was able to achieve escape velocity from a gravity assist, a “gravitational slingshot”, from Jupiter. And actually a surprising fact is that a close flyby of any of the planets can result in escape velocity being achieved by a spacecraft.</span></div><div><span style="font-family: UICTFontTextStyleBody; font-size: large;"><br /></span></div><div><span style="font-family: UICTFontTextStyleBody; font-size: large;"> See the discussion here:</span></div><div><span style="font-family: UICTFontTextStyleBody; font-size: large;"><br /></span></div><div><b style="-webkit-text-size-adjust: auto; font-family: "Times New Roman", serif; font-size: 16px;"><span style="font-size: 16pt;">Gravitational Slingshot</span></b></div><div><table border="0" cellpadding="0" cellspacing="0" class="MsoTableGrid" style="-webkit-text-size-adjust: auto; border-collapse: collapse; border: none; color: black;"><tbody><tr><td style="padding: 0in 5.4pt; width: 6.15in;" valign="top" width="590"><p class="MsoNormal" style="font-family: "Times New Roman", serif; font-size: 12pt; margin: 0in 0in 0.0001pt;"><i>An extreme form of the maneuver would be to approach a planet head-on at a speed v while the planet is moving directly toward us at a speed U (both speeds defined relative to the "fixed" Solar frame). If we aim just right we can loop around behind the planet in an extremely eccentric hyperbolic orbit, making a virtual 180-degree turn, as illustrated below.</i></p></td></tr><tr><td style="padding: 0in 5.4pt; width: 6.15in;" valign="top" width="590"><p class="MsoNormal" style="font-family: "Times New Roman", serif; font-size: 12pt; margin: 0in 0in 0.0001pt;"> </p></td></tr><tr><td style="padding: 0in 5.4pt; width: 6.15in;" valign="top" width="590"><p align="center" class="MsoNormal" style="font-family: "Times New Roman", serif; font-size: 12pt; margin: 0in 0in 0.0001pt; text-align: center;"><img height="87" src="https://www.mathpages.com/home/kmath114/kmath114_files/image001.png" width="156" /></p></td></tr><tr><td style="padding: 0in 5.4pt; width: 6.15in;" valign="top" width="590"><p class="MsoNormal" style="font-family: "Times New Roman", serif; font-size: 12pt; margin: 0in 0in 0.0001pt;"> </p></td></tr><tr><td style="padding: 0in 5.4pt; width: 6.15in;" valign="top" width="590"><p class="MsoNormal" style="font-family: "Times New Roman", serif; font-size: 12pt; margin: 0in 0in 0.0001pt;"><i>The net effect is almost as if we "bounced" off the front of the planet. From the planet's perspective we approached at the speed U+v, and therefore we will also recede at the speed U+v relative to the planet, but the planet is still moving at (virtually) the speed U, so we will be moving at speed 2U+v. This is just like a very small billiard ball bouncing off a very large one.</i></p></td></tr><tr><td style="padding: 0in 5.4pt; width: 6.15in;" valign="top" width="590"><p class="MsoNormal" style="font-family: "Times New Roman", serif; font-size: 12pt; margin: 0in 0in 0.0001pt;"><a href="https://www.mathpages.com/home/kmath114/kmath114.htm"><span style="font-size: large;">https://www.mathpages.com/home/kmath114/kmath114.htm</span></a></p></td></tr></tbody></table></div><div><span style="font-family: UICTFontTextStyleBody; font-size: large;"><br /></span></div><div><span style="font-family: UICTFontTextStyleBody; font-size: large;"> You see the maximum added velocity due to the gravity assist is about twice the speed of the planets orbital velocity around the Sun. But the escape velocity at a planets distance from the Sun is square-root of 2 times its orbital velocity. So a spacecraft encountering the planet at sufficiently close distance and at the right angle could achieve escape velocity from a gravity assist.</span></div><div><span style="font-family: UICTFontTextStyleBody; font-size: large;"><br /></span></div><div><span style="font-family: UICTFontTextStyleBody; font-size: large;"> Then the Messenger launchers upper stage following Messenger’s trajectory, during one of the Messenger flyby’s, </span><span style="font-size: large;"><span style="font-family: UICTFontTextStyleBody;">or even one years later, could due t</span><span style="font-family: UICTFontTextStyleBody;">o small variations in the flight path be sent on an even closer encounter to the planet than Messenger and thus achieve escape velocity. </span></span></div><div><span style="font-family: UICTFontTextStyleBody; font-size: large;"><br /></span></div><div><span style="font-family: UICTFontTextStyleBody; font-size: large;"> But if this is true how is it the simulations projecting backwards ‘Oumuamua’s trajectory show the closest approach to the inner planets millions of kilometers away not the hundreds to thousands of kilometers away needed for a gravitational slingshot? </span></div><div><span style="font-family: UICTFontTextStyleBody; font-size: large;"> </span></div><div><span style="font-family: UICTFontTextStyleBody; font-size: large;"> Note that when you project back a trajectory you assume the object has not at some point flipped the direction it is traveling. But in the most extreme case that is exactly what can happen with a gravitational slingshot, as shown in the diagram above.</span></div><div><span style="font-family: UICTFontTextStyleBody; font-size: large;"><br /></span></div><div><span style="font-family: UICTFontTextStyleBody; font-size: large;"> This can be taken account in such trajectory simulations if you know a gravity assist did take place. That is to say, an alteration in the flight path in such a case can be taken into account, even if not necessarily to the most extreme case of reversing direction. </span></div><div><span style="font-family: UICTFontTextStyleBody; font-size: x-large;"><br /></span></div><div><span style="font-family: UICTFontTextStyleBody; font-size: large;"> But there is a scenario where you did not know it. You see an object have a certain speed and a certain direction at a certain time, say, when it passes closest to Earth. You project backwards and note the distance at closest distance to, say, Venus is millions of kilometers away from that planet</span></div><div><span style="font-family: UICTFontTextStyleBody; font-size: large;"><br /></span></div><div><span style="font-family: UICTFontTextStyleBody; font-size: large;"> But IF that object at some <i>earlier</i> time than the time of the supposed Venus closest approach the object had a higher speed then the object could still have made a gravitational slingshot flyby of the planet with Venus being at a different location.</span></div><div><span style="font-family: UICTFontTextStyleBody; font-size: large;"><br /></span></div><div><span style="font-family: UICTFontTextStyleBody; font-size: large;"> Then to see if this did happen in the ‘Oumuamua case you would have to project back further then the supposed closest approaches of Venus and Mercury to see if at earlier times gravitational slingshots by these planets could have resulted in it appearing at the same location, speed, and direction as observed when it made its closest approach to Earth. The calculations are made more complicated though by the possibility of it having multiple flybys.</span></div><div><span style="font-family: UICTFontTextStyleBody; font-size: large;"><br /></span></div><div><span style="font-family: UICTFontTextStyleBody; font-size: large;"><b>Detections by radio telescopes?</b></span></div><div><span style="font-family: UICTFontTextStyleBody; font-size: large;"><br /></span></div><div><span style="font-family: UICTFontTextStyleBody; font-size: large;"> The possibility that spent rocket stages can be mistaken for asteroids suggest additional observational techniques should be made when they are discovered. ‘Oumuamua was scanned to see if it was emanating radio transmissions, and none were found. But it still might have been detectable by radio telescopes or by radar. It might have been determined for example if it were more reflective than usual suggesting it was made of metal.</span></div><div><span style="font-family: UICTFontTextStyleBody; font-size: large;"><br /></span></div><div><span style="font-family: UICTFontTextStyleBody; font-size: large;"><br /></span></div><div><span style="font-family: UICTFontTextStyleBody; font-size: large;"> Robert Clark</span></div><div><div><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody><tr><td style="text-align: center;"><br /></td></tr><tr><td class="tr-caption" style="text-align: center;"><div style="text-align: left;"><br /></div></td></tr></tbody></table><span style="font-family: UICTFontTextStyleBody;"><br /></span><p></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s2" style="font-family: UICTFontTextStyleBody;"><br /></span></p><p class="p3" style="-webkit-text-size-adjust: auto; font-size: 23px; font-stretch: normal; line-height: normal; margin: 0px;"><span class="s2" style="font-family: UICTFontTextStyleBody;"><br /></span></p></div></div></div>Robert Clarkhttp://www.blogger.com/profile/16114043697010364282noreply@blogger.com0tag:blogger.com,1999:blog-7598615455712402973.post-65241225957090423232023-09-01T19:27:00.003-04:002023-09-01T19:54:12.121-04:00 Further strangeness of 'Oumuamua.<p style="text-align: center;"><i> Copyright 2023 Robert Clark</i></p><p style="text-align: center;"><i><br /></i></p><p style="text-align: left;"> Harvard astronomer Avi Loeb listed 6 strange things about the interstellar object 'Oumuamua unexpected in a naturally occuring asteroid or comet:</p><p>6 Strange Facts about the Interstellar Visitor 'Oumuamua<br />By Abraham Loeb on November 20, 2018<br /><a href="https://blogs.scientificamerican.com/observations/6-strange-facts-about-the-interstellar-visitor-oumuamua/">https://blogs.scientificamerican.com/observations/6-strange-facts-about-the-interstellar-visitor-oumuamua/</a></p><p> Software engineer Adam Hibberd of the <a href="https://i4is.org/" target="_blank"><i>Initiative for 4 Interstellar Studies</i>(i4is)</a> has also discussed the unusual aspects of the interstellar object in regards to its point of origin and perihelion distance:</p><p>‘Oumuamua: Some More Strangeness<br />16 June 2022<br /><a href="https://i4is.org/oumuamua-some-more-strangeness/">https://i4is.org/oumuamua-some-more-strangeness/</a></p><p> Hibberd noted the trajectory parameters of 'Oumuamua were such they would only happen about 2.5% of the time. He also noted the unusal aspects of 'Oumuamua's trajectory made it more likely for it to be detected from Earth. But by that same token, wouldn't that also mean for a supposed craft observing Earth the trajectory characteristics would make the observations easier?</p><p> In that regard, note some further odd properties of 'Oumuamua are described below.</p><p>1.)See the speeds of 'Oumuamua by distance from the Sun here:</p><table class="wikitable floatright" style="background-color: #f8f9fa; border-collapse: collapse; border: 1px solid rgb(162, 169, 177); clear: right; color: #202122; float: right; font-family: sans-serif; font-size: 0.9em; margin: 0px 0px 0.5em 0.5em; text-align: center;"><caption style="font-weight: bold;">Oumuamua speed relative to the Sun<sup class="reference" id="cite_ref-Horizons_67-0" style="font-size: 10.08px; font-weight: normal; line-height: 1; text-wrap: nowrap; unicode-bidi: isolate;"><a href="https://en.wikipedia.org/wiki/%CA%BBOumuamua#cite_note-Horizons-67" style="background: none; color: #3366cc; overflow-wrap: break-word; text-decoration-line: none;">[63]</a></sup></caption><tbody><tr><th style="background-color: #eaecf0; border: 1px solid rgb(162, 169, 177); padding: 0.2em 0.4em; text-align: center;">Distance</th><th style="background-color: #eaecf0; border: 1px solid rgb(162, 169, 177); padding: 0.2em 0.4em; text-align: center;">Date</th><th style="background-color: #eaecf0; border: 1px solid rgb(162, 169, 177); padding: 0.2em 0.4em; text-align: center;">Velocity<br />km/s</th></tr><tr><td style="border: 1px solid rgb(162, 169, 177); padding: 0.2em 0.4em;">2300 AU</td><td style="border: 1px solid rgb(162, 169, 177); padding: 0.2em 0.4em;">1605</td><td style="border: 1px solid rgb(162, 169, 177); padding: 0.2em 0.4em;">26.34</td></tr><tr><td style="border: 1px solid rgb(162, 169, 177); padding: 0.2em 0.4em;">1000 AU</td><td style="border: 1px solid rgb(162, 169, 177); padding: 0.2em 0.4em;">1839</td><td style="border: 1px solid rgb(162, 169, 177); padding: 0.2em 0.4em;">26.35</td></tr><tr><td style="border: 1px solid rgb(162, 169, 177); padding: 0.2em 0.4em;">100 AU</td><td style="border: 1px solid rgb(162, 169, 177); padding: 0.2em 0.4em;">2000</td><td style="border: 1px solid rgb(162, 169, 177); padding: 0.2em 0.4em;">26.67</td></tr><tr><td style="border: 1px solid rgb(162, 169, 177); padding: 0.2em 0.4em;">10 AU</td><td style="border: 1px solid rgb(162, 169, 177); padding: 0.2em 0.4em;">2016</td><td style="border: 1px solid rgb(162, 169, 177); padding: 0.2em 0.4em;">29.50</td></tr><tr><td style="border: 1px solid rgb(162, 169, 177); padding: 0.2em 0.4em;"><b>1 AU</b></td><td style="border: 1px solid rgb(162, 169, 177); padding: 0.2em 0.4em;"><b>9 August 2017</b></td><td style="border: 1px solid rgb(162, 169, 177); padding: 0.2em 0.4em;"><b>49.67</b></td></tr><tr><td style="border: 1px solid rgb(162, 169, 177); padding: 0.2em 0.4em;"><a class="mw-redirect" href="https://en.wikipedia.org/wiki/Perihelion_and_aphelion" style="background: none; color: #3366cc; overflow-wrap: break-word; text-decoration-line: none;" title="Perihelion and aphelion">Perihelion</a></td><td style="border: 1px solid rgb(162, 169, 177); padding: 0.2em 0.4em;">9 September 2017</td><td style="border: 1px solid rgb(162, 169, 177); padding: 0.2em 0.4em;">87.71<sup class="reference" id="cite_ref-pseudoMPEC_12-2" style="font-size: 10.08px; line-height: 1; text-wrap: nowrap; unicode-bidi: isolate;"><a href="https://en.wikipedia.org/wiki/%CA%BBOumuamua#cite_note-pseudoMPEC-12" style="background: none; color: #3366cc; overflow-wrap: break-word; text-decoration-line: none;">[10]</a></sup></td></tr><tr><td style="border: 1px solid rgb(162, 169, 177); padding: 0.2em 0.4em;">1 AU</td><td style="border: 1px solid rgb(162, 169, 177); padding: 0.2em 0.4em;">10 October 2017</td><td style="border: 1px solid rgb(162, 169, 177); padding: 0.2em 0.4em;">49.67<sup class="reference" id="cite_ref-68" style="font-size: 10.08px; line-height: 1; text-wrap: nowrap; unicode-bidi: isolate;"><a href="https://en.wikipedia.org/wiki/%CA%BBOumuamua#cite_note-68" style="background: none; color: #3366cc; overflow-wrap: break-word; text-decoration-line: none;">[e]</a></sup></td></tr><tr><td style="border: 1px solid rgb(162, 169, 177); padding: 0.2em 0.4em;">10 AU</td><td style="border: 1px solid rgb(162, 169, 177); padding: 0.2em 0.4em;">2019</td><td style="border: 1px solid rgb(162, 169, 177); padding: 0.2em 0.4em;">29.51</td></tr><tr><td style="border: 1px solid rgb(162, 169, 177); padding: 0.2em 0.4em;">100 AU</td><td style="border: 1px solid rgb(162, 169, 177); padding: 0.2em 0.4em;">2034</td><td style="border: 1px solid rgb(162, 169, 177); padding: 0.2em 0.4em;">26.65</td></tr><tr><td style="border: 1px solid rgb(162, 169, 177); padding: 0.2em 0.4em;">1000 AU</td><td style="border: 1px solid rgb(162, 169, 177); padding: 0.2em 0.4em;">2196</td><td style="border: 1px solid rgb(162, 169, 177); padding: 0.2em 0.4em;">26.36</td></tr><tr><td style="border: 1px solid rgb(162, 169, 177); padding: 0.2em 0.4em;">2300 AU</td><td style="border: 1px solid rgb(162, 169, 177); padding: 0.2em 0.4em;">2430</td><td style="border: 1px solid rgb(162, 169, 177); padding: 0.2em 0.4em;">26.32</td></tr></tbody></table><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /> Notable is that the velocity of 'Oumuamua at 1 AU of 49.67 km/s is close to the escape velocity from the Sun at 1 AU, i.e., the escape velocity from the Sun at Earth's distance from the Sun, of 42 km/s.<div><br /></div><div> If you think of a natural interstellar asteroid then its speed passing 1 AU could be below escape velocity at that distance or above it. But for an artificial interstellar satellite, you don't want it to be below escape velocity from the Sun because you wouldn't want it captured in that system you are examining. So you would want it above the escape velocity, but not too far above it so as to allow accurate observations.</div><div><br /></div><div> Then it would be useful to examine the odds of 'Oumuamua having a speed at 1 AU so close to Earth's escape velocity.</div><div><br /></div><div><br /></div><div>2.)The closeness of 'Oumuamua to the Earth at closest approach of 0.16 AU was quite surprising considering it is an interstellar object. But also unexpected is the closeness it came to the other planets of the inner solar system:</div><div><br /></div><div>This animation shows the trajectory of 'Oumuamua in relation to Mercury, Venus, and Earth:</div><div><br /></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhbibcDZPtivyzVnsoBQg3iRtlDF2fj9RJQqKRoUaCkZbIY_OPKjko4RFV8BCp9N_tZQCL0YlJaK8amzTwY8cVuQybhSy9Q6DFmVl94qEqbcozks-V0CevUOb-s7wrsWHWhNJwJiUQ9xRwybvqr_gfuH0jWdRevoyXXqVgtgk7xatMBQ558VKooFfYiV0U/s800/256F6D7C-DB8E-4BF8-B3B3-15928EF6A937.gif" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="473" data-original-width="800" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhbibcDZPtivyzVnsoBQg3iRtlDF2fj9RJQqKRoUaCkZbIY_OPKjko4RFV8BCp9N_tZQCL0YlJaK8amzTwY8cVuQybhSy9Q6DFmVl94qEqbcozks-V0CevUOb-s7wrsWHWhNJwJiUQ9xRwybvqr_gfuH0jWdRevoyXXqVgtgk7xatMBQ558VKooFfYiV0U/s16000/256F6D7C-DB8E-4BF8-B3B3-15928EF6A937.gif" /></a></div><div><br /></div> The video provides the distance of 'Oumuamua to those inner planets at closest approach. For Mercury and Venus, it's 0.285 AU and 0.605 AU respectively.<div><br /></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhCoKIxl-R6Lm7DHfmG2GWADRX7Dtd6HTWWJQqEY1K-fI5SXBemjjNp-996oFFGniII7fP0MmVBx63bcjgr0fE4nZHDnbceZM_kiLGp0qsqmBpiltXcj5eZmK9RGJtXpoBa5VghzWoLfmbjb7OJAkoDNBobFUGaT__CvR86h586TVuU3_xdczhOYghvnpU/s2160/image_6483441%20(7).JPG" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1620" data-original-width="2160" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhCoKIxl-R6Lm7DHfmG2GWADRX7Dtd6HTWWJQqEY1K-fI5SXBemjjNp-996oFFGniII7fP0MmVBx63bcjgr0fE4nZHDnbceZM_kiLGp0qsqmBpiltXcj5eZmK9RGJtXpoBa5VghzWoLfmbjb7OJAkoDNBobFUGaT__CvR86h586TVuU3_xdczhOYghvnpU/w640-h480/image_6483441%20(7).JPG" width="640" /></a></div><br /><div><br /><div> And for the Earth. it's 0.163 AU at closest approach:</div><div><br /></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgjR04Kso6HvajBI8mwrm9iUT-bUyhz0E3HH7RY8QHeZRFB7BW9Ewuzz31TXESqzWo2QJTE7jkGnJUMh1yi5RDfWwqGF64rQpIM2fHc7Hc9Jz1jXAsa3hAvtavKVugP17py2r-4buRd3oeyHpI8a56f_vXdSSBgNTQhPfYopZK7x5XMtoZTaZ7rTkGy9Ag/s2160/image_6483441%20(6).JPG" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1620" data-original-width="2160" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgjR04Kso6HvajBI8mwrm9iUT-bUyhz0E3HH7RY8QHeZRFB7BW9Ewuzz31TXESqzWo2QJTE7jkGnJUMh1yi5RDfWwqGF64rQpIM2fHc7Hc9Jz1jXAsa3hAvtavKVugP17py2r-4buRd3oeyHpI8a56f_vXdSSBgNTQhPfYopZK7x5XMtoZTaZ7rTkGy9Ag/w640-h480/image_6483441%20(6).JPG" width="640" /></a></div><br /><div><br /></div><div> While this image showing the closeness of the Earth approach is interesting, something else about it is also interesting. It appears at this time of closest approach to the Earth, all three of Mercury, Venus, Mars would be visible in the sky at the same time from Earth. This is notable because this only happens about one day per year. So there is only about 1/365 chance of this happening. So this multiplies times the unlikelihood of it's trajectory as calculated by Hibberd.</div><div><br /></div><div> As to why this would happen, one could say this supposed artificial visitor wanted a nice picture of all the inner planets in the sky at the same time. But I think a likelier possibility is the intent was to have close approaches of all the inner planets. The parameters of such a trajectory necessitated at some point Mercury, Venus. and Mars would be visible in the sky at the same time from Earth.</div><div><br /></div><div> Given this fact, a calculation of the odds should be made of the trajectory parameters being such that 'Oumuamua made such close approaches to Mercury, Venus, and Earth.</div><div><br /></div><div> Robert Clark<br /><br /><p style="text-align: center;"><br /><br /></p></div></div>Robert Clarkhttp://www.blogger.com/profile/16114043697010364282noreply@blogger.com0tag:blogger.com,1999:blog-7598615455712402973.post-72097241235456683552023-08-16T19:07:00.003-04:002023-08-17T06:41:24.736-04:00Game changer for propellant generation on the Moon.<p style="text-align: center;"><i><span style="font-family: arial;"> Copyright 2023 Robert Clark</span></i></p><p style="text-align: center;"><i><span style="font-family: arial;"><br /></span></i></p><h4 style="text-align: left;"><span style="font-family: arial;">ABSTRACT</span></h4><p style="text-align: left;"><span style="font-family: arial;"><i> Proponents of getting propellant from the Moon for spacecraft already in Earth orbit, as for orbital propellant depots, base this on using high power to separate hydrogen and oxygen by electrolysis applied to the water ice in the Moon's south polar region. However, quite surprisingly there may already be free hydrogen at the Moon's south pole or available in far more energy efficient way then by electrolysis. This hydrogen may be so easily obtainable then it may be it can be profitably shipped to Earth for a clean energy economy.</i></span></p><p style="text-align: left;"><span style="font-family: arial;"><br /></span></p><h4 style="text-align: left;"><span style="font-family: arial;">Free Propellant on Mars and the Moon.</span></h4><p style="text-align: left;"><span style="font-family: arial;"> In the blog post "<a href="https://exoscientist.blogspot.com/2023/07/potential-game-changer-for-generating.html" target="_blank">Potential Game-Changer for Generating Propellant on Mars</a>," I suggested that getting <i>free</i> oxygen and carbon monoxide from the Martian atmosphere would provide a free means of producing propellant on Mars. This is important since rather than requiring several football fields of solar panels or a nuclear power plant to generate the megawatts of power needed to separate the C<span style="background-color: white; color: #212529;">O</span><span style="background-color: white; bottom: -0.25em; box-sizing: border-box; color: #212529; line-height: 0; position: relative; vertical-align: baseline;">2</span> or H2O into carbon, oxygen, and hydrogen by electrolysis, we could actually <i>generate</i> megawatts of<i> </i>power after collecting the free CO and <span style="background-color: white; color: #212529;">O</span><span style="background-color: white; bottom: -0.25em; box-sizing: border-box; color: #212529; line-height: 0; position: relative; vertical-align: baseline;">2</span> in the Martian air then combusting them together:</span></p><p style="text-align: left;"><span style="font-family: arial;"><span class="base" style="background: rgb(255, 255, 255); border: 0px; box-sizing: border-box; color: #222222; display: inline-block; font-size: 18px; letter-spacing: -0.5px; margin: 0px; outline: 0px; padding: 0px; position: relative; white-space: nowrap; width: min-content;"><span class="mord" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">2</span><span class="mord mathnormal" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px 0.07153em 0px 0px; outline: 0px; padding: 0px; position: static;">C</span><span class="mord mathnormal" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px 0.02778em 0px 0px; outline: 0px; padding: 0px; position: static;">O</span><span class="mspace" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; margin: 0px 0.222222em 0px 0px; outline: 0px; padding: 0px; position: static;"></span><span class="mbin" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">+</span><span class="mspace" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; margin: 0px 0.222222em 0px 0px; outline: 0px; padding: 0px; position: static;"></span></span><span class="base" style="background: rgb(255, 255, 255); border: 0px; box-sizing: border-box; color: #222222; display: inline-block; font-size: 18px; letter-spacing: -0.5px; margin: 0px 0px 3px; outline: 0px; padding: 0px; position: relative; white-space: nowrap; width: min-content;"><span class="strut" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; height: 0.83333em; margin: 0px; outline: 0px; padding: 0px; position: static; vertical-align: -0.15em;"></span><span class="mord" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;"><span class="mord mathnormal" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px 0.02778em 0px 0px; outline: 0px; padding: 0px; position: static;">O</span><span class="msupsub" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; margin: 0px; outline: 0px; padding: 2px 0px; position: relative;"><span class="vlist-t vlist-t2" style="background: transparent; border-collapse: collapse; border: 0px; box-sizing: border-box; display: inline-table; margin: 0px -2px 0px 0px; outline: 0px; padding: 0px; position: static; table-layout: fixed;"><span class="vlist-r" style="background: transparent; border: 0px; box-sizing: border-box; display: table-row; margin: 0px; outline: 0px; padding: 0px; position: static;"><span class="vlist" style="background: transparent; border: 0px; box-sizing: border-box; display: table-cell; height: 0.301108em; margin: 0px; outline: 0px; padding: 0px; position: relative; vertical-align: bottom;"><span style="background: transparent; border: 0px; box-sizing: border-box; display: block; height: 0px; margin: 0px 0.05em 0px -0.02778em; outline: 0px; padding: 0px; position: relative; top: -2.55em;"><span class="pstrut" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; height: 2.7em; margin: 0px; outline: 0px; overflow: hidden; padding: 0px; position: static; width: 0px;"></span><span class="sizing reset-size6 size3 mtight" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; font-size: 0.7em; margin: 0px; outline: 0px; padding: 0px; position: static;"><span class="mord mtight" style="background: transparent; border: 0px; box-sizing: border-box; font-size: 12.6px; margin: 0px; outline: 0px; padding: 0px; position: static;"><span class="mord mtight" style="background: transparent; border: 0px; box-sizing: border-box; font-size: 12.6px; margin: 0px; outline: 0px; padding: 0px; position: static;">2</span></span></span></span></span><span class="vlist-s" style="background: transparent; border: 0px; box-sizing: border-box; display: table-cell; font-size: 1px; margin: 0px; min-width: 2px; outline: 0px; padding: 0px; position: static; vertical-align: bottom; width: 2px;"></span></span><span class="vlist-r" style="background: transparent; border: 0px; box-sizing: border-box; display: table-row; margin: 0px; outline: 0px; padding: 0px; position: static;"><span class="vlist" style="background: transparent; border: 0px; box-sizing: border-box; display: table-cell; height: 0.15em; margin: 0px; outline: 0px; padding: 0px; position: relative; vertical-align: bottom;"><span style="background: transparent; border: 0px; box-sizing: border-box; display: block; height: 0px; margin: 0px; outline: 0px; padding: 0px; position: relative;"></span></span></span></span></span></span><span class="mspace" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; margin: 0px 0.277778em 0px 0px; outline: 0px; padding: 0px; position: static;"></span><span class="mrel" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">→</span><span class="mspace" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; margin: 0px 0.277778em 0px 0px; outline: 0px; padding: 0px; position: static;"></span></span><span class="base" style="background: rgb(255, 255, 255); border: 0px; box-sizing: border-box; color: #222222; display: inline-block; font-size: 18px; letter-spacing: -0.5px; margin: 0px 0px 3px; outline: 0px; padding: 0px; position: relative; white-space: nowrap; width: min-content;"><span class="strut" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; height: 0.87777em; margin: 0px; outline: 0px; padding: 0px; position: static; vertical-align: -0.19444em;"></span><span class="mord" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">2</span><span class="mord mathnormal" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px 0.07153em 0px 0px; outline: 0px; padding: 0px; position: static;">C</span><span class="mord" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;"><span class="mord mathnormal" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px 0.02778em 0px 0px; outline: 0px; padding: 0px; position: static;">O</span><span class="msupsub" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; margin: 0px; outline: 0px; padding: 2px 0px; position: relative;"><span class="vlist-t vlist-t2" style="background: transparent; border-collapse: collapse; border: 0px; box-sizing: border-box; display: inline-table; margin: 0px -2px 0px 0px; outline: 0px; padding: 0px; position: static; table-layout: fixed;"><span class="vlist-r" style="background: transparent; border: 0px; box-sizing: border-box; display: table-row; margin: 0px; outline: 0px; padding: 0px; position: static;"><span class="vlist" style="background: transparent; border: 0px; box-sizing: border-box; display: table-cell; height: 0.301108em; margin: 0px; outline: 0px; padding: 0px; position: relative; vertical-align: bottom;"><span style="background: transparent; border: 0px; box-sizing: border-box; display: block; height: 0px; margin: 0px 0.05em 0px -0.02778em; outline: 0px; padding: 0px; position: relative; top: -2.55em;"><span class="pstrut" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; height: 2.7em; margin: 0px; outline: 0px; overflow: hidden; padding: 0px; position: static; width: 0px;"></span><span class="sizing reset-size6 size3 mtight" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; font-size: 0.7em; margin: 0px; outline: 0px; padding: 0px; position: static;"><span class="mord mtight" style="background: transparent; border: 0px; box-sizing: border-box; font-size: 12.6px; margin: 0px; outline: 0px; padding: 0px; position: static;"><span class="mord mtight" style="background: transparent; border: 0px; box-sizing: border-box; font-size: 12.6px; margin: 0px; outline: 0px; padding: 0px; position: static;">2</span></span></span></span></span><span class="vlist-s" style="background: transparent; border: 0px; box-sizing: border-box; display: table-cell; font-size: 1px; margin: 0px; min-width: 2px; outline: 0px; padding: 0px; position: static; vertical-align: bottom; width: 2px;"></span></span><span class="vlist-r" style="background: transparent; border: 0px; box-sizing: border-box; display: table-row; margin: 0px; outline: 0px; padding: 0px; position: static;"><span class="vlist" style="background: transparent; border: 0px; box-sizing: border-box; display: table-cell; height: 0.15em; margin: 0px; outline: 0px; padding: 0px; position: relative; vertical-align: bottom;"><span style="background: transparent; border: 0px; box-sizing: border-box; display: block; height: 0px; margin: 0px; outline: 0px; padding: 0px; position: relative;"></span></span></span></span></span></span><span class="mpunct" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">;</span><span class="mspace" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; margin: 0px 0.166667em 0px 0px; outline: 0px; padding: 0px; position: static;"></span><span class="mord" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">Δ</span><span class="mord mathnormal" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px 0.08125em 0px 0px; outline: 0px; padding: 0px; position: static;">H</span><span class="mspace" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; margin: 0px 0.277778em 0px 0px; outline: 0px; padding: 0px; position: static;"></span><span class="mrel" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">=</span><span class="mspace" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; margin: 0px 0.277778em 0px 0px; outline: 0px; padding: 0px; position: static;"></span></span><span class="base" style="background: rgb(255, 255, 255); border: 0px; box-sizing: border-box; color: #222222; display: inline-block; font-size: 18px; letter-spacing: -0.5px; margin: 0px 0px 3px; outline: 0px; padding: 0px; position: relative; white-space: nowrap; width: min-content;"><span class="strut" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; height: 1em; margin: 0px; outline: 0px; padding: 0px; position: static; vertical-align: -0.25em;"></span><span class="mord" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">−</span><span class="mord" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">5</span><span class="mord" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">6</span><span class="mord" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">9</span><span class="mord mathnormal" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px 0.03148em 0px 0px; outline: 0px; padding: 0px; position: static;">k</span><span class="mord mathnormal" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px 0.09618em 0px 0px; outline: 0px; padding: 0px; position: static;">J</span><span class="mord" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">/</span><span class="mord mathnormal" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">m</span><span class="mord mathnormal" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">o</span><span class="mord mathnormal" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px 0.01968em 0px 0px; outline: 0px; padding: 0px; position: static;">l</span></span></span></p><p style="text-align: left;"><span style="font-family: arial;"> This may may seem odd that we can generate power by collecting the natural resources already there but note this is exactly what we're doing when we collect the coal or petroleum or uranium from the ground on Earth. You get far more potential energy out than what you put in to collect it.</span></p><p style="text-align: left;"><span style="font-family: arial;"> And in fact we could also generate hydrogen in a way that at the same time generates power as well. This comes from the reaction:</span></p><p style="text-align: left;"><span style="font-family: arial;"><span style="background-color: white; color: #212529;">1.)CO + H</span><span style="background-color: white; bottom: -0.25em; box-sizing: border-box; color: #212529; line-height: 0; position: relative; vertical-align: baseline;">2</span><span style="background-color: white; color: #212529;">O → CO</span><span style="background-color: white; bottom: -0.25em; box-sizing: border-box; color: #212529; line-height: 0; position: relative; vertical-align: baseline;">2</span><span style="background-color: white; color: #212529;">+ H</span><span style="background-color: white; bottom: -0.25em; box-sizing: border-box; color: #212529; line-height: 0; position: relative; vertical-align: baseline;">2, </span><span style="background-color: #fbfaf5; color: #666666; white-space: pre;">Δ</span><span style="background-color: white; color: #212529; white-space: pre;">H = -41 kJ/mol</span><span style="background-color: white; color: #212529;"> </span></span></p><p style="text-align: left;"><span style="font-family: arial;"><span style="background-color: white; color: #212529;"> </span><span style="background-color: white; color: #212529;">The </span><span style="background-color: white; color: #212529;">H</span><span style="background-color: white; bottom: -0.25em; box-sizing: border-box; color: #212529; line-height: 0; position: relative; vertical-align: baseline;">2</span><span style="background-color: white; color: #212529;">O could come from the abundant ice in the Martian soil or in fact from the Martian air as well.</span><span style="background-color: white; color: #212529;"> </span><span style="background-color: white; color: #212529;">The hydrogen(</span><span style="background-color: white; color: #212529;">H</span><span style="background-color: white; bottom: -0.25em; box-sizing: border-box; color: #212529; line-height: 0; position: relative; vertical-align: baseline;">2</span><span style="background-color: white; color: #212529;">) would then come from what is called the water-gas shift reaction: </span></span></p><p style="background-color: white; color: #202122; font-size: 14px; margin: 0.5em 0px;"><span style="font-family: arial;"><br /></span></p><p style="background-color: white; color: #202122; font-size: 14px; margin: 0.5em 0px;"><span style="font-family: arial;">The <b>water–gas shift reaction</b> (WGSR) describes the reaction of <a href="https://en.wikipedia.org/wiki/Carbon_monoxide" style="background: none; color: #3366cc; overflow-wrap: break-word; text-decoration-line: none;" title="Carbon monoxide">carbon monoxide</a> and <a href="https://en.wikipedia.org/wiki/Water_vapor" style="background: none; color: #3366cc; overflow-wrap: break-word; text-decoration-line: none;" title="Water vapor">water vapor</a> to form <a href="https://en.wikipedia.org/wiki/Carbon_dioxide" style="background: none; color: #3366cc; overflow-wrap: break-word; text-decoration-line: none;" title="Carbon dioxide">carbon dioxide</a> and <a href="https://en.wikipedia.org/wiki/Hydrogen" style="background: none; color: #3366cc; overflow-wrap: break-word; text-decoration-line: none;" title="Hydrogen">hydrogen</a>:</span></p><dl style="background-color: white; color: #202122; font-size: 14px; margin-bottom: 0.5em; margin-top: 0.2em;"><dd style="margin-bottom: 0.1em; margin-left: 1.6em; margin-right: 0px;"><span style="font-family: arial;">CO + H<sub style="font-size: 11.2px; line-height: 1;">2</sub>O ⇌ CO<sub style="font-size: 11.2px; line-height: 1;">2</sub> + H<sub style="font-size: 11.2px; line-height: 1;">2</sub></span></dd></dl><p style="background-color: white; color: #202122; font-size: 14px; margin: 0.5em 0px;"><span style="font-family: arial;">The water gas shift reaction was discovered by Italian physicist <a href="https://en.wikipedia.org/wiki/Felice_Fontana" style="background: none; color: #3366cc; overflow-wrap: break-word; text-decoration-line: none;" title="Felice Fontana">Felice Fontana</a> in 1780. It was not until much later that the industrial value of this reaction was realized. Before the early 20th century, hydrogen was obtained by reacting steam under high pressure with <a href="https://en.wikipedia.org/wiki/Iron" style="background: none; color: #3366cc; overflow-wrap: break-word; text-decoration-line: none;" title="Iron">iron</a> to produce <a href="https://en.wikipedia.org/wiki/Iron_oxide" style="background: none; color: #3366cc; overflow-wrap: break-word; text-decoration-line: none;" title="Iron oxide">iron oxide</a> and hydrogen. With the development of industrial processes that required hydrogen, such as the <a class="mw-redirect" href="https://en.wikipedia.org/wiki/Haber%E2%80%93Bosch" style="background: none; color: #3366cc; overflow-wrap: break-word; text-decoration-line: none;" title="Haber–Bosch">Haber–Bosch</a> <a href="https://en.wikipedia.org/wiki/Ammonia" style="background: none; color: #3366cc; overflow-wrap: break-word; text-decoration-line: none;" title="Ammonia">ammonia</a> synthesis, a less expensive and more efficient method of hydrogen production was needed. As a resolution to this problem, the WGSR was combined with the <a href="https://en.wikipedia.org/wiki/Coal_gasification" style="background: none; color: #3366cc; overflow-wrap: break-word; text-decoration-line: none;" title="Coal gasification">gasification of coal</a> to produce hydrogen. As the idea of <a href="https://en.wikipedia.org/wiki/Hydrogen_economy" style="background: none; color: #3366cc; overflow-wrap: break-word; text-decoration-line: none;" title="Hydrogen economy">hydrogen economy</a> gains popularity, the focus on hydrogen as an energy storage medium when an alternative replacement energy source for hydrocarbons is used.</span></p><p style="background-color: white; margin: 0.5em 0px;"><span style="color: #202122; font-family: arial;"><span style="font-size: 14px;"><a href="https://en.wikipedia.org/wiki/Water%E2%80%93gas_shift_reaction">https://en.wikipedia.org/wiki/Water%E2%80%93gas_shift_reaction</a></span></span></p><p style="background-color: white; margin: 0.5em 0px;"><span style="font-family: arial;"><span style="color: #202122;"> </span></span></p><p style="background-color: white; margin: 0.5em 0px;"><span style="font-family: arial;"><span style="color: #202122;"> However, it may be this process can also work on the Moon. The LCROSS mission to my mind may have been one of the most significant planetary science missions ever conducted by NASA, as measured in relation to its cost. It was designed as a low cost "Discovery" class mission but what it returned was profoundly important. It had an ingenious design that sent a rocket stage to impact the Moon at the south polar region and observe spectroscopically the material sent up in the impact plume by a second spacecraft..</span></span></p><p style="background-color: white; margin: 0.5em 0px;"><span style="font-family: arial;"><span style="color: #202122;"> The mission confirmed what was suspected that there was great amounts of water as ice in the Moon's south polar region. In fact LCROSS found an extensive list of volatiles concentrated at the south pole of the Moon:</span></span></p><p style="background-color: white; margin: 0.5em 0px;"><span style="font-family: arial;"><span style="color: #202122;"><br /></span></span></p><p style="background-color: white; margin: 0.5em 0px;"><span style="font-family: arial;"><span style="color: #222222;">Moon Blast Reveals Lunar Surface Rich With Compounds.</span><br style="color: #222222;" /><span style="color: #222222;">Science Oct 21, 2010 2:05 PM EDT.</span><br style="color: #222222;" /><i style="color: #222222;">There is water on the moon … along with a long list of other compounds, including, mercury, gold and silver. That’s according to a more detailed analysis of the chilled lunar soil near the moon’s South Pole, released as six papers by a large team of scientists in the journal, Science Thursday.</i><br style="color: #222222;" /><a href="https://www.pbs.org/newshour/science/its-confirmed-there-is-water" style="color: #2288bb; text-decoration-line: none;">https://www.pbs.org/newshour/science/its-confirmed-there-is-water</a></span></p><p style="background-color: white; margin: 0.5em 0px;"><span style="font-family: arial;"><br /></span></p><p style="background-color: white; margin: 0.5em 0px;"><span style="font-family: arial;"> The amounts of volatiles found by LCROSS was extraordinary:</span></p><p style="background-color: white; margin: 0.5em 0px;"><span style="font-family: arial;"><br /></span></p><p style="background-color: white; margin: 0.5em 0px;"><span style="font-family: arial;">Lunar Impact Uncovered More Than Just Moon Water.</span></p><p style="background-color: white; margin: 0.5em 0px;"><span style="font-family: arial;">Oct. 21, 2010: Nearly a year after announcing the discovery of water molecules on the moon, scientists have revealed new data uncovered by NASA's Lunar CRater Observation and Sensing Satellite, or LCROSS, and Lunar Reconnaissance Orbiter, or LRO—and it's more than just water.</span></p><p style="background-color: white; margin: 0.5em 0px;"><i><span style="font-family: arial;">In addition to water, the plume contained "volatiles." These are compounds that freeze in the cold lunar craters and vaporize easily when warmed by the sun. The suite of LCROSS and LRO instruments determined as much as <b>20 percent</b> of the material kicked up by the LCROSS impact was volatiles, including methane, ammonia, <b>hydrogen gas, carbon dioxide and carbon monoxide.</b></span></i></p><p style="background-color: white; margin: 0.5em 0px;"><span style="font-family: arial;"><a href="https://science.nasa.gov/science-news/science-at-nasa/2010/21oct_lcross2">https://science.nasa.gov/science-news/science-at-nasa/2010/21oct_lcross2</a> </span></p><p style="background-color: white; margin: 0.5em 0px;"><span style="color: #202122; font-family: arial;"><span style="font-size: 14px;"><br /></span></span></p><p style="background-color: white; margin: 0.5em 0px;"><span style="color: #202122; font-family: arial;"> These last three are quite important in regards to the lunar propellant issue. If the hydrogen is indeed free then that gives us a ready made source for the clean-energy hydrogen. However, I suspect the hydrogen seen from orbit after the rocket stage impact, was derived from the water-gas shift reaction. This reaction shown in eq. 1.) reacts carbon monoxide and water to produce hydrogen and carbon dioxide and is helped by high temperatures, as would have obtained after the rocket stage impact. So the carbon monoxide could have reacted with the water to generate hydrogen.</span></p><p style="background-color: white; margin: 0.5em 0px;"><span style="color: #202122; font-family: arial;"> Once we have hydrogen then we can send it back to Earth for clean energy. The gravity and required launch speed from the Moon is so low we could use continual launch methods such as railguns or even the space elevator, which is possible with current materials under the Moons low gravity.</span></p><p style="background-color: white; margin: 0.5em 0px;"><span style="color: #202122; font-family: arial;"> As in the case of the getting hydrogen or other propellants on Mars <a href="https://www.blogger.com/blog/post/edit/7598615455712402973/7209724123545668355#" target="_blank">discussed in the prior blog post</a>, we would need low energy separation methods. A new method sounds quite promising:</span></p><p style="background-color: white; margin: 0.5em 0px;"><span style="color: #202122; font-family: arial;"><br /></span></p><p style="background-color: white; margin: 0.5em 0px;"><span style="color: #202122; font-family: arial;">Mechanochemical breakthrough unlocks cheap, safe, powdered hydrogen</span></p><p style="background-color: white; margin: 0.5em 0px;"><span style="font-family: arial;"><span style="color: #202122;">By Loz Blain </span><span style="color: #202122;">July 18, 2022</span></span></p><p style="background-color: white; margin: 0.5em 0px;"><span style="color: #202122; font-family: arial;"><i>Australian scientists say they've made a "eureka moment" breakthrough in gas separation and storage that could radically reduce energy use in the petrochemical industry, while making hydrogen much easier and safer to store and transport in a powder.</i></span></p><p style="background-color: white; margin: 0.5em 0px;"></p><p style="background-color: white; margin: 0.5em 0px;"><span style="color: #202122; font-family: arial;"><a href="https://newatlas.com/energy/mechanochemical-breakthrough-unlocks-cheap-safe-powdered-hydrogen/">https://newatlas.com/energy/mechanochemical-breakthrough-unlocks-cheap-safe-powdered-hydrogen/</a></span></p><p style="background-color: white; margin: 0.5em 0px;"><span style="color: #202122; font-family: arial;"> </span></p><p style="background-color: white; margin: 0.5em 0px;"><span style="color: #202122; font-family: arial;"> This proposed solution for low energy gas separation though still needs to be confirmed by other researchers. </span></p><p style="background-color: white; margin: 0.5em 0px;"><span style="color: #202122; font-family: arial;"><span style="font-size: 14px;"><br /></span></span></p><h4 style="background-color: white; margin: 0.5em 0px; text-align: left;"><span style="color: #202122; font-family: arial;"> Hydrogen on the Moon Cheaper and Cleaner than on Earth?</span></h4><div><span style="color: #202122; font-family: arial;"> The Department of Energy(DOE) set a goal in 2021 to reduce the cost of producing hydrogen in a clean fashion by 80% to $1 per kg in 1 decade. The chemical methods for producing hydrogen can already do it about a $1 per kg cost, but results in additional CO2 being added to the atmosphere. Using solar power for a clean energy hydrogen generation approach is more expensive. This described on this DOE page:</span></div><div><span face="sans-serif" style="color: #202122;"><span style="font-size: 14px;"><br /></span></span></div><div><span style="color: #202122; font-family: inherit;"><span style="font-size: 14px;"><br /></span></span></div><div><div style="background-color: white; box-sizing: border-box; color: #333333; font-size: 16px; margin: 0px; padding: 0px;"><h2 class="factsheetTitle" style="background-color: #f9f9f9; border-bottom: thin solid rgb(193, 193, 193); border-top: thin solid rgb(193, 193, 193); bottom: 10px; box-sizing: border-box; color: #656565; font-size: 30px; line-height: 1.5; margin: 10px 0px; padding: 20px 5px; position: relative; text-shadow: rgba(109, 109, 109, 0.29) 2px 2px 1px; text-transform: uppercase;"><span style="font-family: inherit;">7.1. WHY HYDROGEN?</span></h2></div><div property="schema:text" style="background-color: white; box-sizing: border-box; margin: 0px; padding: 0px;"><p style="box-sizing: border-box; color: #333333; font-size: 16px; margin: 5px 0px 20px; padding: 0px; text-shadow: none;"><span style="font-family: inherit;">Clean hydrogen is of the greatest interest in addressing the climate crisis, with the recognition that hydrogen could play a crucial role in economy-wide decarbonization, particularly in the transportation and industrial sectors including sustainable fuels, iron & steel, ammonia and chemicals, and more.<span style="box-sizing: border-box; font-size: 12px; line-height: 0; margin: 0px; padding: 0px; position: relative; top: -0.5em; vertical-align: baseline;"><a href="https://www.netl.doe.gov/research/Coal/energy-systems/gasification/gasifipedia/hydrogen#sdfootnote1sym" id="sdfootnote1anc" name="sdfootnote1anc" style="background-color: transparent; box-sizing: border-box; color: black; font-size: 16px; margin: 0px; padding: 0px; text-shadow: none;">1</a></span> Hydrogen is an extremely clean energy carrier, as its consumption produces only water; it also has a high energy density by mass. Hydrogen can be used to power <a href="https://netl.doe.gov/coal/fuel-cells" style="background-color: transparent; box-sizing: border-box; color: black; margin: 0px; padding: 0px; text-shadow: none;">fuel cells</a> or combusted in a <a href="https://netl.doe.gov/coal/turbines" style="background-color: transparent; box-sizing: border-box; color: black; margin: 0px; padding: 0px; text-shadow: none;">hydrogen turbine</a> to generate electricity, and could also serve as clean transportation fuel.</span></p><p style="box-sizing: border-box; color: #333333; font-size: 16px; margin: 5px 0px 20px; padding: 0px; text-shadow: none;"><span style="font-family: inherit;">The first Energy Earthshot, the <a href="https://www.energy.gov/eere/fuelcells/hydrogen-shot" style="background-color: transparent; box-sizing: border-box; color: black; margin: 0px; padding: 0px; text-shadow: none;">Hydrogen Shot</a> launched in 2021, seeks to reduce the cost of clean hydrogen by 80% to $1 per kilogram in 1 decade. This is an ambitious initiative, since current costs of clean hydrogen are much higher. For example, electrolytic generation of hydrogen using renewable electricity costs at least $6 per kilogram.</span></p><p style="box-sizing: border-box; color: #333333; font-size: 16px; margin: 5px 0px 20px; padding: 0px; text-shadow: none;"><span style="font-family: inherit;">Worldwide, about half of all hydrogen production is from reforming of natural gas (mainly steam methane reforming or SMR), with the remainder deriving from gasification of liquid and solid feedstocks such as coal, petcoke, and petroleum residuals, from oil as a byproduct, and with a few percent from electrolysis. Syngas from gasification already contains a significant amount of hydrogen, which can be increased through <a href="https://netl.doe.gov/research/coal/energy-systems/gasification/gasifipedia/water-gas-shift" style="background-color: transparent; box-sizing: border-box; color: black; margin: 0px; padding: 0px; text-shadow: none;">water gas shift</a> (WGS) and separated into a pure hydrogen product meeting industry product quality standards. There are several conventional hydrogen separation processes, with the well-proven and moderate cost pressure swing adsorption (PSA) methods commonly chosen. PSA has the ability to produce high purity (99.9%) hydrogen at near feed pressure; however, relatively high hydrogen concentration in feed gases is required for its economics to remain favorable.</span></p><p style="box-sizing: border-box; color: #333333; font-size: 16px; margin: 5px 0px 20px; padding: 0px; text-shadow: none;"><span style="font-family: inherit;">For either natural gas reforming or gasification routes, hydrogen production costs are lower than the electrolytic route, but the challenge is that the carbon footprint of conventional hydrogen production is large, as shown in the following table:</span></p><table border="1" cellpadding="7" cellspacing="0" style="background: none 0px 0px repeat scroll transparent; border-collapse: collapse; border: 1px solid rgb(221, 221, 221); color: #333333; font-size: 16px; margin: 0px; padding: 0px; width: 100%;"><tbody style="box-sizing: border-box; margin: 0px; padding: 0px;"><tr style="box-sizing: border-box; color: #333333; font-size: 16px; margin: 0px; padding: 0px; text-shadow: none;" valign="TOP"><th style="background: padding-box padding-box rgb(105, 105, 105); box-sizing: border-box; color: white; font-weight: 400; margin: 0px; padding: 0px; text-align: left; text-shadow: none;" width="40%"><p class="text-align-center" style="box-sizing: border-box; color: #333333; margin: 5px 0px 20px; padding: 0px; text-align: center; text-shadow: none;"><span style="font-family: inherit;"> </span></p></th><th style="background: padding-box padding-box rgb(105, 105, 105); box-sizing: border-box; color: white; font-weight: 400; margin: 0px; padding: 0px; text-align: left; text-shadow: none;"><p class="text-align-center" style="box-sizing: border-box; color: #333333; margin: 5px 0px 20px; padding: 0px; text-align: center; text-shadow: none;"><span style="box-sizing: border-box; color: white; margin: 0px; padding: 0px;"><span style="font-family: inherit;">Hydrogen product (kg/h)</span></span></p></th><th style="background: padding-box padding-box rgb(105, 105, 105); box-sizing: border-box; color: white; font-weight: 400; margin: 0px; padding: 0px; text-align: left; text-shadow: none;"><p class="text-align-center" style="box-sizing: border-box; color: #333333; margin: 5px 0px 20px; padding: 0px; text-align: center; text-shadow: none;"><span style="box-sizing: border-box; color: white; margin: 0px; padding: 0px;"><span style="font-family: inherit;">CO<span style="bottom: -0.25em; box-sizing: border-box; font-size: 12px; line-height: 0; margin: 0px; padding: 0px; position: relative; vertical-align: baseline;">2</span> product (kg/h)</span></span></p></th><th style="background: padding-box padding-box rgb(105, 105, 105); box-sizing: border-box; color: white; font-weight: 400; margin: 0px; padding: 0px; text-align: left; text-shadow: none;"><p class="text-align-center" style="box-sizing: border-box; color: #333333; margin: 5px 0px 20px; padding: 0px; text-align: center; text-shadow: none;"><span style="box-sizing: border-box; color: white; margin: 0px; padding: 0px;"><span style="font-family: inherit;">CO<span style="bottom: -0.25em; box-sizing: border-box; font-size: 12px; line-height: 0; margin: 0px; padding: 0px; position: relative; vertical-align: baseline;">2</span> emitted in stack gas (kg/h)</span></span></p></th><th style="background: padding-box padding-box rgb(105, 105, 105); box-sizing: border-box; color: white; font-weight: 400; margin: 0px; padding: 0px; text-align: left; text-shadow: none;"><p class="text-align-center" style="box-sizing: border-box; color: #333333; margin: 5px 0px 20px; padding: 0px; text-align: center; text-shadow: none;"><span style="box-sizing: border-box; color: white; margin: 0px; padding: 0px;"><span style="font-family: inherit;">Carbon intensity kg CO<span style="bottom: -0.25em; box-sizing: border-box; font-size: 12px; line-height: 0; margin: 0px; padding: 0px; position: relative; vertical-align: baseline;">2</span>/kg H<span style="bottom: -0.25em; box-sizing: border-box; font-size: 12px; line-height: 0; margin: 0px; padding: 0px; position: relative; vertical-align: baseline;">2</span></span></span></p></th></tr><tr style="box-sizing: border-box; color: #333333; font-size: 16px; margin: 0px; padding: 0px; text-shadow: none;"><td style="background: padding-box padding-box rgba(255, 255, 255, 0); box-sizing: border-box; margin: 0px; padding: 0px; text-shadow: none;"><p class="text-align-center" style="box-sizing: border-box; margin: 5px 0px 20px; padding: 0px; text-align: center; text-shadow: none;"><span style="font-family: inherit;">SMR w/ 90% capture</span></p></td><td style="background: padding-box padding-box rgba(255, 255, 255, 0); box-sizing: border-box; margin: 0px; padding: 0px; text-shadow: none;"><p class="text-align-center" style="box-sizing: border-box; margin: 5px 0px 20px; padding: 0px; text-align: center; text-shadow: none;"><span style="font-family: inherit;">25,700</span></p></td><td style="background: padding-box padding-box rgba(255, 255, 255, 0); box-sizing: border-box; margin: 0px; padding: 0px; text-shadow: none;"><p class="text-align-center" style="box-sizing: border-box; margin: 5px 0px 20px; padding: 0px; text-align: center; text-shadow: none;"><span style="font-family: inherit;">227,600</span></p></td><td style="background: padding-box padding-box rgba(255, 255, 255, 0); box-sizing: border-box; margin: 0px; padding: 0px; text-shadow: none;"><p class="text-align-center" style="box-sizing: border-box; margin: 5px 0px 20px; padding: 0px; text-align: center; text-shadow: none;"><span style="font-family: inherit;">25,300</span></p></td><td style="background: padding-box padding-box rgba(255, 255, 255, 0); box-sizing: border-box; margin: 0px; padding: 0px; text-shadow: none;"><p class="text-align-center" style="box-sizing: border-box; margin: 5px 0px 20px; padding: 0px; text-align: center; text-shadow: none;"><span style="font-family: inherit;">1.0</span></p></td></tr><tr style="box-sizing: border-box; color: #333333; font-size: 16px; margin: 0px; padding: 0px; text-shadow: none;"><td style="background: padding-box padding-box rgba(255, 255, 255, 0); box-sizing: border-box; margin: 0px; padding: 0px; text-shadow: none;"><p class="text-align-center" style="box-sizing: border-box; margin: 5px 0px 20px; padding: 0px; text-align: center; text-shadow: none;"><span style="font-family: inherit;">Coal gasification w/ 90% capture</span></p></td><td style="background: padding-box padding-box rgba(255, 255, 255, 0); box-sizing: border-box; margin: 0px; padding: 0px; text-shadow: none;"><p class="text-align-center" style="box-sizing: border-box; margin: 5px 0px 20px; padding: 0px; text-align: center; text-shadow: none;"><span style="font-family: inherit;">25,700</span></p></td><td style="background: padding-box padding-box rgba(255, 255, 255, 0); box-sizing: border-box; margin: 0px; padding: 0px; text-shadow: none;"><p class="text-align-center" style="box-sizing: border-box; margin: 5px 0px 20px; padding: 0px; text-align: center; text-shadow: none;"><span style="font-family: inherit;">456,700</span></p></td><td style="background: padding-box padding-box rgba(255, 255, 255, 0); box-sizing: border-box; margin: 0px; padding: 0px; text-shadow: none;"><p class="text-align-center" style="box-sizing: border-box; margin: 5px 0px 20px; padding: 0px; text-align: center; text-shadow: none;"><span style="font-family: inherit;">49,300</span></p></td><td style="background: padding-box padding-box rgba(255, 255, 255, 0); box-sizing: border-box; margin: 0px; padding: 0px; text-shadow: none;"><p class="text-align-center" style="box-sizing: border-box; margin: 5px 0px 20px; padding: 0px; text-align: center; text-shadow: none;"><span style="font-family: inherit;">1.9</span></p></td></tr></tbody></table><p class="text-align-center" style="box-sizing: border-box; color: #333333; font-size: 16px; margin: 5px 0px 20px; padding: 0px; text-align: center; text-shadow: none;"><em style="box-sizing: border-box; margin: 0px; padding: 0px;"><span style="font-family: inherit;">Carbon Intensities of SMR and Coal Gasification-based Hydrogen Production (with 90% capture)</span></em></p><p style="box-sizing: border-box; color: #333333; font-size: 16px; margin: 5px 0px 20px; padding: 0px; text-shadow: none;"><i><span style="font-family: inherit;">If all CO<span style="bottom: -0.25em; box-sizing: border-box; font-size: 12px; line-height: 0; margin: 0px; padding: 0px; position: relative; vertical-align: baseline;">2</span> produced in these processes is emitted, and CO<span style="bottom: -0.25em; box-sizing: border-box; font-size: 12px; line-height: 0; margin: 0px; padding: 0px; position: relative; vertical-align: baseline;">2</span> footprint ranges from about 10 to 20 times the mass of the hydrogen produced. Only 0.7% of fossil fuel-based hydrogen production is currently performed in conjunction with carbon capture and storage.<a href="https://www.netl.doe.gov/research/Coal/energy-systems/gasification/gasifipedia/hydrogen#sdfootnote2sym" id="sdfootnote1anc" name="sdfootnote1anc" style="background-color: transparent; box-sizing: border-box; color: black; margin: 0px; padding: 0px; text-shadow: none;">2</a></span></i></p><p style="box-sizing: border-box; color: #333333; font-size: 16px; margin: 5px 0px 20px; padding: 0px; text-shadow: none;"><span style="font-family: inherit;">The gasification route to hydrogen presents an opportunity to use low-cost and liability feedstocks including biomass, solid wastes, and waste coal, which could help reduce the environmental costs and liabilities of solid waste disposal and legacy waste impoundments. Carbon-neutral biomass feedstocks significant reduce the carbon footprint of gasification, and combined with high levels of carbon capture facilitated by high syngas concentrations of CO<span style="bottom: -0.25em; box-sizing: border-box; font-size: 12px; line-height: 0; margin: 0px; padding: 0px; position: relative; vertical-align: baseline;">2</span> and hydrogen characteristic of efficient gasification processes, production of clean hydrogen from gasification could be a compelling option in the emerging decarbonized economy.</span></p><p style="box-sizing: border-box; color: #333333; font-size: 16px; margin: 5px 0px 20px; padding: 0px; text-shadow: none;"><span style="font-family: inherit;">__________________________________________________________________</span></p><p style="box-sizing: border-box; margin: 5px 0px 20px; padding: 0px; text-shadow: none;"><span style="color: #333333;"><a href="https://www.netl.doe.gov/research/Coal/energy-systems/gasification/gasifipedia/hydrogen">https://www.netl.doe.gov/research/Coal/energy-systems/gasification/gasifipedia/hydrogen</a></span></p><p style="box-sizing: border-box; color: #333333; font-family: Roboto, Arial; font-size: 16px; margin: 5px 0px 20px; padding: 0px; text-shadow: none;"> Note then on the Moon, either the hydrogen is already free, or it can be obtained by the water-gas shift reaction that obtains for the low cost chemical production methods used on Earth. But now this can be considered clean production, at least in regards to Earth, in that the CO2 released would be on the Moon.</p><p style="box-sizing: border-box; color: #333333; font-family: Roboto, Arial; font-size: 16px; margin: 5px 0px 20px; padding: 0px; text-shadow: none;"> As for energy generation actually solar or nuclear generation would not be needed. The materials for energy generation would be available in the Moon's regolith, according to the LCROSS results. See here:.</p><div class="separator" style="clear: both; color: #333333; font-size: 16px; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj7N5-9KX64uspfR4U0gvrmlUaOogSwK1dD5rn85TLNuC99aYTY5LwdaqNr55NBJzADITDYCmM8GHHJxwEy-YxM-jIecN5mWcMXoFwRnocoEqxiDvM_t0mPKJ8m86rEoVyLQBMBJy46VivoRfyTgLLTJEOpAh8n57fu_BJoGt9LpPhc6dCoYYkvYPRPSrI/s680/DbG158TVAAEdYfs.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="511" data-original-width="680" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj7N5-9KX64uspfR4U0gvrmlUaOogSwK1dD5rn85TLNuC99aYTY5LwdaqNr55NBJzADITDYCmM8GHHJxwEy-YxM-jIecN5mWcMXoFwRnocoEqxiDvM_t0mPKJ8m86rEoVyLQBMBJy46VivoRfyTgLLTJEOpAh8n57fu_BJoGt9LpPhc6dCoYYkvYPRPSrI/w640-h480/DbG158TVAAEdYfs.jpg" width="640" /></a></div><br /><p style="box-sizing: border-box; color: #333333; font-family: Roboto, Arial; font-size: 16px; margin: 5px 0px 20px; padding: 0px; text-shadow: none;"> You see there are abundances listed for H2 and H2O and CO and CO2 but nothing for O2 for combustion. Oxygen could be obtained from high temperature burning of lunar rocks, but this is energy intensive. We want an energy production method that does not require high energy input in the first place.</p><p style="box-sizing: border-box; color: #333333; font-size: 16px; margin: 5px 0px 20px; padding: 0px; text-shadow: none;"><span style="font-family: Roboto, Arial;"> One possibility might be to use the free magnesiu</span><span style="font-family: arial;">m Mg seen in the LCROSS data</span><span style="font-family: Roboto, Arial;">. Magnesium can burn in CO2 without requiring oxygen:</span></p><div style="color: #333333;"><span style="font-family: arial;">The General Chemistry Demo Lab</span></div><div style="color: #333333;"><span style="font-family: arial;">Reaction Of Magnesium Metal With Carbon Dioxide.</span></div><div style="color: #333333;"><a href="http://www.ilpi.com/genchem/demo/co2mg/index.html" style="color: #2288bb; text-decoration-line: none;"><span style="font-family: arial;">http://www.ilpi.com/genchem/demo/co2mg/index.html</span></a></div><div style="color: #333333; font-size: 16px;"><br style="background-color: #fbfaf5; color: #222222; font-family: verdana; font-size: small;" /></div><p style="box-sizing: border-box; color: #333333; font-family: Roboto, Arial; font-size: 16px; margin: 5px 0px 20px; padding: 0px; text-shadow: none;"> Another possibility would be to use the free sodium Na seen by LCROSS. <a href="https://chemistrytalk.org/sodium-in-water-reaction/" target="_blank">Sodium reacts explosively with water releasing heat and also hydrogen, so this might provide an additional method of producing hydrogen.</a></p><p style="box-sizing: border-box; color: #333333; font-family: Roboto, Arial; font-size: 16px; margin: 5px 0px 20px; padding: 0px; text-shadow: none;"><br /></p><p style="box-sizing: border-box; color: #333333; font-family: Roboto, Arial; font-size: 16px; margin: 5px 0px 20px; padding: 0px; text-shadow: none;"> Robert Clark</p></div></div>Robert Clarkhttp://www.blogger.com/profile/16114043697010364282noreply@blogger.com2tag:blogger.com,1999:blog-7598615455712402973.post-47281874133137094182023-08-14T14:45:00.003-04:002023-08-16T19:15:53.913-04:00SpaceX should withdraw its application for the Starship as an Artemis lunar lander.<p style="text-align: center;"> <i>Copyright 2023 Robert Clark</i></p><p style="text-align: center;"><i><br /></i></p><p><span style="font-size: medium;"> In the blog post, "<a href="https://exoscientist.blogspot.com/2023/03/superheavystarship-have-thermal-energy.html" target="_blank">SuperHeavy+Starship have the thermal energy of the Hiroshima bomb. UPDATED</a>". I noted the thermal energy content of both stages is comparable to the explosive force of the Hiroshima bomb, ca. 15 kilotons of TNT. However, it is quite important to keep in mind that NASA uses estimates of the <i>explosive force</i> of a possible rocket explosion that is <i>some fraction</i> of what the total thermal energy might be. Based on this, I estimated the explosive force might actually be in the range of 3.4 to 5.4 kilotons. This is as much as 5 times higher than the explosive force attributed to the famous Soviet N-1 rocket failures at ca. 1.2 kilotons. </span></p><p><span style="font-size: medium;"> To get an idea of the enormity of 1.2 kilotons explosive force, and remembering also an SH/ST explosion might be as much as 5 times more powerful, look at the case of the Beirut explosion of 2020. This was not a rocket explosion but of ammonium nitrate but its estimated explosive force was about that of N-1 rocket at ca. 1.1 kilotons.</span></p><p></p><div class="separator" style="clear: both; text-align: center;"><iframe allowfullscreen="" class="BLOG_video_class" height="291" src="https://www.youtube.com/embed/LNDhIGR-83w" width="350" youtube-src-id="LNDhIGR-83w"></iframe></div> <p></p><p> <a href="https://en.wikipedia.org/wiki/2020_Beirut_explosion#Damage" style="font-size: large;" target="_blank">In the explosion, homes as far away as 10 kilometers were damaged and the terminals at the Beirut airport 10 km away suffered moderate damage with some doors and windows blown out.</a></p><p><span style="font-size: medium;"> Note now populated areas such as Port Isabel consisting of thousands of residents are within 10 km of the SH/ST launch site, and an explosion of this rocket might be 5 times more powerful than the Beirut explosion.</span></p><p><span style="font-size: medium;"> In my blog post, I argued that not sufficient attention was being given to the possibility of an explosion by either the FAA or NASA. I wrote to one of NASA's safety offices and was told the safety of commercial launches is not the purview of NASA, but of the FAA. But when NASA is depending on that the commercial rocket to complete the planned flagship space program of NASA they have a responsibility to ensure that rocket is being developed safely as well.</span></p><p><span style="font-size: medium;"> With the failure of the April 20th test flight of the Superheavy/Starship fortunately now both NASA and the FAA are giving closer scrutiny of the safety of the rocket as it should be.</span></p><h4 style="text-align: left;"><span style="font-size: medium;">The Superheavy/Starship actually <i>is</i> the N-1 rocket.</span></h4><p><span style="font-size: medium;"> The explosive force of the N-1 rocket, comparable to that of the devastating Beirut explosion, serves as a cautionary tale for those in the space industry. The comparison has been made of the SpaceX SuperHeavy/Starship approach to the Soviet multiple failed N-1 rocket in that they both wanted to test by actually flying the full rocket until it works, despite the number of failures. </span></p><p><span style="font-size: medium;"> This comparison was criticized on the grounds the N-1 engines were not tested individually. Instead, the engineers on the N-1 selected an engine at random from a batch to see if that worked. If it worked the entire batch was chosen. The engines could not be tested individually because the testing was destructive. That engine could not be used if it were first tested.</span></p><p><span style="font-size: medium;"> The SpaceX Raptor engines on the other hand are tested individually. But here’s the <i>major</i> failing of the Raptor: even if the engine is tested successfully there is still a quite high chance the engine will still fail when used on a flight. That is a <i>major</i> flaw in a rocket engine. No rocket engine would be considered successfully developed with that flaw.</span></p><p><span style="font-size: medium;"> Because of the numerous failures of the Raptor both on the test stand and in short test hops of the Starship landing methods prior to the April test flight, I estimated the chance of engine failures of the SuperHeavy/Starship test flight was 1 out of 3. SpaceX claimed prior to the April test flight their Raptor 2 was more reliable. The result? <i>Only</i> 1 in 4 of the engines failed. That is still a stunningly high percentage. As a point of comparison it would be like on every flight of the Falcon 9 the expectation would be at least two of the engines would fail during each flight.</span></p><p></p><p><span style="font-size: medium;"> The upshot of this in a very real sense the Super/Starship <i>is</i> just like the failed Soviet N-1 in flying with engines with poor reliability.</span></p><p><span style="font-size: medium;"> It is my contention the attempt of SpaceX trying to reach a 2025 deadline to have the SH/SS flying and with multiple successful test flights completed puts undue pressure on its normal safety procedures. For that reason my opinion is it should withdraw the Starship for consideration as a lander for the Artemis III lander mission.</span></p><p><span style="font-size: medium;"> Robert Clark</span></p><div><br /></div>Robert Clarkhttp://www.blogger.com/profile/16114043697010364282noreply@blogger.com2tag:blogger.com,1999:blog-7598615455712402973.post-81039797540468108562023-08-11T12:00:00.002-04:002023-08-11T13:27:15.265-04:00Possibilities for a single launch architecture of the Artemis missions, Page 3: Saving the lander mission for Artemis III.<p style="text-align: center;"><span style="font-size: medium;"> <i>Copyright 2023 Robert Clark</i></span></p><p style="text-align: center;"><br /></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px;"><span style="font-family: UICTFontTextStyleBody;"><span style="font-size: medium;"> I discussed a possible single-launch lunar lander architecture here:</span></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px;"><span style="font-size: medium;"><span style="font-family: UICTFontTextStyleBody;"></span><br /></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px;"><span style="font-family: UICTFontTextStyleBody;"><span style="font-size: medium;">Possibilities for a single launch architecture of the Artemis missions, Page 2: using the Boeing Exploration Upper Stage.</span></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px;"><span style="font-family: UICTFontTextStyleBody;"><a data-saferedirecturl="https://www.google.com/url?q=http://exoscientist.blogspot.com/2023/08/possibilities-for-single-launch.html&source=gmail&ust=1691852182682000&usg=AOvVaw2W6038Q9ZQHTa5yPBHX8vI" href="http://exoscientist.blogspot.com/2023/08/possibilities-for-single-launch.html" style="color: #1155cc;" target="_blank"><span style="font-size: medium;">http://exoscientist.blogspot.<wbr></wbr>com/2023/08/possibilities-for-<wbr></wbr>single-launch.html</span></a></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px;"><span style="font-size: medium;"><span style="font-family: UICTFontTextStyleBody;"></span><br /></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px;"><span style="font-family: UICTFontTextStyleBody;"><span style="font-size: medium;"> <a href="https://www.orlandosentinel.com/2023/08/09/spacex-starship-delays-could-shift-artemis-iii-away-from-moon-landing-official-says/" target="_blank">The SpaceX delay in the Starship HLS development has led to NASA considering that Artemis might not even be a lander mission.</a> This leaves open the possibility to save the lander mission for the Artemis III mission alternative methods for landers should be considered.</span></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px;"><span style="font-size: medium;"><span style="font-family: UICTFontTextStyleBody;"></span><br /></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px;"><span style="font-family: UICTFontTextStyleBody;"><span style="font-size: medium;"> Plus, there is the fact many knowledgeable space aficionados from the old days really do not like the SpaceX plan of using 8 to 16 refueling flights just for one lunar lander mission.</span></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px;"><span style="font-size: medium;"><span style="font-family: UICTFontTextStyleBody;"></span><br /></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px;"><span style="font-family: UICTFontTextStyleBody;"><span style="font-size: medium;"> This plan for a replacement lander could be done rather quickly and at low cost because it would use already existing space assets. Also, it would be done by our European partners so would not require NASA expenditures using all European space components. That would save $3 billion that NASA would have had to pay to SpaceX for their lander.</span></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px;"><span style="font-size: medium;"><span style="font-family: UICTFontTextStyleBody;"></span><br /></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px;"><span style="font-family: UICTFontTextStyleBody;"><span style="font-size: medium;"> This would involve even greater European involvement in successfully accomplishing the Artemis missions than just Orion’s service module so would undoubtedly get enthusiastic support from the ESA.</span></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px;"><span style="font-size: medium;"><span style="font-family: UICTFontTextStyleBody;"></span><br /></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px;"><span style="font-family: UICTFontTextStyleBody;"><span style="font-size: medium;"> It is notable that the ESA has expressed even greater support for lunar colonization plans than even NASA. This ESA produced lunar lander would allow them to further their own plans for a sustained human presence on the Moon.</span></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px;"><span style="font-size: medium;"><span style="font-family: UICTFontTextStyleBody;"></span><br /></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px;"><span style="font-family: UICTFontTextStyleBody;"><span style="font-size: medium;"> About ESA’s ATV-derived service module for Orion, that again would require low cost modifications in this plan. It would need just an addition 10 tons of propellant, which would fit easily within a service module diameter expanded to match the Orion’s diameter. Again this cost would be covered by our European partners, with no expenditure by NASA.</span></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px;"><span style="font-size: medium;"><span style="font-family: UICTFontTextStyleBody;"></span><br /></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px;"><span style="font-family: UICTFontTextStyleBody;"><span style="font-size: medium;"> Those two factors would be the easiest aspects of the plan. It might be difficult to believe a lunar lander would be among the “easiest” parts of the plan. But keep it mind it would be derived from already existing space assets.</span></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px;"><span style="font-size: medium;"><span style="font-family: UICTFontTextStyleBody;"></span><br /></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px;"><span style="font-family: UICTFontTextStyleBody;"><span style="font-size: medium;"> The trickiest aspects of the plan would be the fact the SLS would require higher payload capability to allow for the higher propellant load of the service module of 10 tons and a ca. 15 ton mass lunar lander.</span></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px;"><span style="font-size: medium;"><span style="font-family: UICTFontTextStyleBody;"></span><br /></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px;"><span style="font-family: UICTFontTextStyleBody;"><span style="font-size: medium;"> One possibility, keeping the Boeing EUS, is to put atop it a third stage consisting of the 50-ton Centaur V, as discussed in, "</span></span><span style="font-family: UICTFontTextStyleBody; font-size: large;"><a href="http://exoscientist.blogspot.com/2023/08/possibilities-for-single-launch.html" target="_blank">Possibilities for a single launch architecture of the Artemis missions, Page 2: using the Boeing Exploration Upper Stage</a>."</span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px;"><span style="font-size: medium;"><span style="font-family: UICTFontTextStyleBody;"></span><br /></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px;"><span style="font-family: UICTFontTextStyleBody;"><span style="font-size: medium;"> However, I’m still not convinced the Boeing EUS is the best way to go because of its expense and its small size. If a cryogenic upper stage at a propellant load of ca. 200 ton size instead of the Boeing EUS ca. 125 tons were used, then this larger upper stage itself could do TLI burn carrying the Orion, larger SM, and ca. 15 tons lunar lander.</span></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px;"><span style="font-size: medium;"><span style="font-family: UICTFontTextStyleBody;"></span><br /></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px;"><span style="font-family: UICTFontTextStyleBody;"><span style="font-size: medium;"> I discuss here how such a larger cryogenic stage could be done in a much cheaper fashion than the Boeing EUS approach: </span></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px;"><span style="font-size: medium;"><span style="font-family: UICTFontTextStyleBody;"></span><br /></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px;"><span style="font-family: UICTFontTextStyleBody;"><span style="font-size: medium;">Why does the Boeing Exploration Upper Stage(EUS) cost so much? </span></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px;"><span style="font-family: UICTFontTextStyleBody;"><a data-saferedirecturl="https://www.google.com/url?q=http://exoscientist.blogspot.com/2022/11/why-does-boeing-exploration-upper.html&source=gmail&ust=1691852182683000&usg=AOvVaw3Oef-VZx0auyK1nW-iG5eF" href="http://exoscientist.blogspot.com/2022/11/why-does-boeing-exploration-upper.html" style="color: #1155cc;" target="_blank"><span style="font-size: medium;">http://exoscientist.blogspot.<wbr></wbr>com/2022/11/why-does-boeing-<wbr></wbr>exploration-upper.html</span></a></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px;"><span style="font-size: medium;"><span style="font-family: UICTFontTextStyleBody;"></span><br /></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px;"><span style="font-family: UICTFontTextStyleBody;"><span style="font-size: medium;"> I call this the trickiest aspect of the plan because Boeing has shown repeated delays in getting the core stage ready so the same might happen with their EUS stage, especially when it would have to be moved up to be ready by the 2025 Artemis III launch date, instead of on Artemis IV in 2028. </span></span><span style="font-family: UICTFontTextStyleBody; font-size: medium;">As for the extra Centaur V third stage, since it is expected to first launch this year, likely it will have several launches under its belt by a 2025 Artemis III launch date.</span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px;"><span style="font-family: UICTFontTextStyleBody;"><span style="font-size: medium;"><br /></span></span></p><p class="_1qeIAgB0cPwnLhDF9XSiJM" style="background-color: white; border: 0px; color: #1c1c1c; font-stretch: inherit; font-variant-east-asian: inherit; font-variant-numeric: inherit; line-height: inherit; margin: 0px; padding: 0px 0px 0.25em; vertical-align: baseline;"><span style="font-family: inherit; font-size: medium;"> <span style="font-family: inherit;">Note though a MAJOR reason why the development of the different versions of the SLS was arranged as it was was because of cost reasons. The development of the Boeing EUS was pushed back to delay paying for its <em class="_7s4syPYtk5hfUIjySXcRE" style="border: 0px; font-stretch: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;">wildly</em> overpriced development costs. Note too not having to pay for the SpaceX Starship lander would save NASA $3 billion.</span></span></p><p class="_1qeIAgB0cPwnLhDF9XSiJM" style="background-color: white; border: 0px; color: #1c1c1c; font-stretch: inherit; font-variant-east-asian: inherit; font-variant-numeric: inherit; line-height: inherit; margin: 0px; padding: 0.8em 0px 0.25em; vertical-align: baseline;"><span style="font-family: inherit; font-size: medium;"> Boeing’s charge to NASA for the EUS is a key reason why I prefer the simpler approach for an upper stage of just basing it on the core with fewer barrel rings. </span></p><p class="_1qeIAgB0cPwnLhDF9XSiJM" style="background-color: white; border: 0px; color: #1c1c1c; font-stretch: inherit; font-variant-east-asian: inherit; font-variant-numeric: inherit; line-height: inherit; margin: 0px; padding: 0.8em 0px 0.25em; vertical-align: baseline;"></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjp5RKyiKjFY1zzAOkezzaLNGshBZSgQJpxuXGQ6cdsmOSKut_Ssz7SjiZxjZ2B0T9K9Au_SY9CGMkzym_2t2tTgcoTlVSldJ3dDQzt2cUZhZCT5Iw12JayPZLm6y7cNqdcbXrreAZ-V0o1RN8g9oFMBHaJLRAbtnGj9khTT7sbljbykP9B1Pt7EnYe/s640/core_stage_expanded.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="472" data-original-width="640" height="472" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjp5RKyiKjFY1zzAOkezzaLNGshBZSgQJpxuXGQ6cdsmOSKut_Ssz7SjiZxjZ2B0T9K9Au_SY9CGMkzym_2t2tTgcoTlVSldJ3dDQzt2cUZhZCT5Iw12JayPZLm6y7cNqdcbXrreAZ-V0o1RN8g9oFMBHaJLRAbtnGj9khTT7sbljbykP9B1Pt7EnYe/w640-h472/core_stage_expanded.jpg" width="640" /></a></div><p></p><p class="_1qeIAgB0cPwnLhDF9XSiJM" style="background-color: white; border: 0px; color: #1c1c1c; font-stretch: inherit; font-variant-east-asian: inherit; font-variant-numeric: inherit; line-height: inherit; margin: 0px; padding: 0.8em 0px 0.25em; vertical-align: baseline;"><span style="font-family: inherit; font-size: medium;"><br /></span></p><p class="_1qeIAgB0cPwnLhDF9XSiJM" style="background-color: white; border: 0px; color: #1c1c1c; font-stretch: inherit; font-variant-east-asian: inherit; font-variant-numeric: inherit; line-height: inherit; margin: 0px; padding: 0.8em 0px 0.25em; vertical-align: baseline;"><span style="font-family: inherit; font-size: medium;">This would also give us the stage more cheaply and more quickly since it involves just using fewer rings on the tanks. If you have ever watched the video of construction taking place at the SpaceX development site, barrel rings of the tanks on the Starship and SuperHeavy are swapped out, replaced, taken-off and put back routinely.</span></p><p class="_1qeIAgB0cPwnLhDF9XSiJM" style="background-color: white; border: 0px; color: #1c1c1c; font-stretch: inherit; font-variant-east-asian: inherit; font-variant-numeric: inherit; line-height: inherit; margin: 0px; padding: 0.8em 0px 0px; vertical-align: baseline;"><span style="font-family: inherit; font-size: medium;"> You’ve heard the mantra of former NASA administrator Dan Goldin, “faster, better, cheaper”? This would be "faster, better, cheaper, and <em class="_7s4syPYtk5hfUIjySXcRE" style="border: 0px; font-stretch: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;">simpler"</em>.</span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px;"><span style="font-size: medium;"><span style="font-family: UICTFontTextStyleBody;"></span><br /></span></p><p style="background-color: white; color: #222222; font-stretch: normal; line-height: normal; margin: 0px;"><span style="font-family: inherit; font-size: medium;"><span><span> Since this is of different design though that also brings into question its availability by a 2025 launch date.</span></span><span> Note that this plan involves several new components. For that reason, we might want to use Artemis III as an unmanned test lander mission. We might even have it be “manned” by human-like robots, with their operation controlled from the ground on Earth.</span></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px;"><span style="font-size: medium;"><span style="font-family: UICTFontTextStyleBody;"></span><br /></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px;"><span style="font-family: UICTFontTextStyleBody;"><span style="font-size: medium;"> In this regard it is notable that several lines of evidence suggest that there might be valuable metals at the lunar South Pole, the planned location for the Artemis III landing. Indeed, the untold trillions of dollars of valuable metals speculated to exist in the main-asteroid belt on <a href="https://www.smithsonianmag.com/smart-news/asteroid-16-psyche-may-be-worth-more-than-planet-earth-at-10-quintillion-in-fine-metals-180979303/" target="_blank">16 Psyche</a> might already exist just next door at the Moon's south pole! I discuss this here:</span></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px;"><span style="font-size: medium;"><span style="font-family: UICTFontTextStyleBody;"></span><br /></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px;"><span style="font-family: UICTFontTextStyleBody;"><span style="font-size: medium;">U.S. will lag behind in utilization of resources on the Moon.</span></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px;"><span style="font-family: UICTFontTextStyleBody;"><a data-saferedirecturl="https://www.google.com/url?q=http://exoscientist.blogspot.com/2023/08/us-will-lag-behind-in-utilization-of.html&source=gmail&ust=1691852182683000&usg=AOvVaw2_oJ7Cg4QiLluFmgx2UJwW" href="http://exoscientist.blogspot.com/2023/08/us-will-lag-behind-in-utilization-of.html" style="color: #1155cc;" target="_blank"><span style="font-size: medium;">http://exoscientist.blogspot.<wbr></wbr>com/2023/08/us-will-lag-<wbr></wbr>behind-in-utilization-of.html</span></a></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px;"><span style="font-size: medium;"><span style="font-family: UICTFontTextStyleBody;"></span><br /></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px;"><span style="font-family: UICTFontTextStyleBody;"><span style="font-size: medium;"> By the way, the title there stems from my dismay that the U.S. rovers to the South Polar location won’t have instruments for detecting heavy metals but the rovers from other countries will. This is such an obvious thing to include, especially when other countries will include them, that it’s mystifying why the U.S. chose not to include them.</span></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px;"><span style="font-size: medium;"><span style="font-family: UICTFontTextStyleBody;"></span><br /></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px;"><span style="font-family: UICTFontTextStyleBody;"><span style="font-size: medium;"> In any case, it would be pretty cool seeing human-like robotic astronauts prospecting for valuable metals at their landing site.</span></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px;"><span style="font-size: medium;"><span style="font-family: UICTFontTextStyleBody;"></span><br /></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px;"><span style="font-family: UICTFontTextStyleBody;"><span style="font-size: medium;">The ESA produced lunar lander I suggest using is of Apollo-like size at ca. 15 tons. But its crew module volume would be much larger as it is based on the Cygnus capsule, given life support. The Apollo lunar lander had a 6.7 cubic meter internal volume. <a href="https://spaceflight101.com/spacecraft/cygnus/" target="_blank">But the Cygnus has an 18.9 internal volume, nearly 3 times that of the Apollo LEM and the expanded version of the Cygnus has a 27 cubic meter internal volume.</a></span></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px;"><span style="font-size: medium;"><span style="font-family: UICTFontTextStyleBody;"></span><br /></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px;"><span style="font-family: UICTFontTextStyleBody;"><span style="font-size: medium;"> But as for sending cargo or habitats to the Moon, the SLS is far too expensive, $2 billion+ per launch, and at too low flight cadence, at best 1 once per year, for that purpose. </span></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px;"><span style="font-size: medium;"><span style="font-family: UICTFontTextStyleBody;"></span><br /></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px;"><span style="font-family: UICTFontTextStyleBody;"><span style="font-size: medium;"> Better to use lower cost launchers such as the Falcon Heavy for the purpose. I estimate using all hydrolox in-space stages, given low-boiloff tech, the FH could get 15 tons one-way to the lunar surface. </span></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px; min-height: 29px;"><span style="font-size: medium;"><span style="font-family: UICTFontTextStyleBody;"></span><br /></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px;"><span style="font-family: UICTFontTextStyleBody;"><span style="font-size: medium;"> Using hydrolox only for the TLI burn but a storable propellant lander stage (so no low-boiloff tech needed), the FH could get 10 tons to the lunar surface.</span></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px;"><span style="font-family: UICTFontTextStyleBody;"><span style="font-size: medium;"><br /></span></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px;"><span style="font-family: UICTFontTextStyleBody;"><span style="font-size: medium;"><br /></span></span></p><p style="background-color: white; color: #222222; font-family: Arial, Helvetica, sans-serif; font-stretch: normal; line-height: normal; margin: 0px;"><span style="font-family: UICTFontTextStyleBody;"><span style="font-size: medium;">Robert Clark</span></span></p><div><span style="font-family: UICTFontTextStyleBody;"><br /></span></div>Robert Clarkhttp://www.blogger.com/profile/16114043697010364282noreply@blogger.com0tag:blogger.com,1999:blog-7598615455712402973.post-59785480527479335802023-08-07T15:23:00.005-04:002024-01-23T09:14:08.027-05:00Possibilities for a single launch architecture of the Artemis missions, Page 2: using the Boeing Exploration Upper Stage.<p style="text-align: center;"> <i>Copyright 2023 Robert Clark</i></p><p style="text-align: center;"><i><br /></i></p><p style="text-align: left;"><span style="font-size: medium;"> A comparison between the Apollo and Orion capsules:</span></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjgCjTPr9CMX0YjKd8D4dqSClbtQ5_myDfeHrnVrId3K4KSABBvJc2LwvYEq9nQTuMnmN_5tyfCaqfj8KKjj_-VE0t6MBv_v2PVPpUQwVmhdwwyBcQ-iek67FHJ_WOzECaGZ7VNpKLs6-fclBp3fHMK0gB4H61YxkhYHXoNIrMppK0p-JwrlvcSqauuhSI/s640/6A41E7D6-5965-4D9D-A692-4D5421C042F6.jpeg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="360" data-original-width="640" height="360" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjgCjTPr9CMX0YjKd8D4dqSClbtQ5_myDfeHrnVrId3K4KSABBvJc2LwvYEq9nQTuMnmN_5tyfCaqfj8KKjj_-VE0t6MBv_v2PVPpUQwVmhdwwyBcQ-iek67FHJ_WOzECaGZ7VNpKLs6-fclBp3fHMK0gB4H61YxkhYHXoNIrMppK0p-JwrlvcSqauuhSI/w640-h360/6A41E7D6-5965-4D9D-A692-4D5421C042F6.jpeg" width="640" /></a></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: left;"><span style="font-size: large;"> Rarely has a design mistake been so clearly illuminated by a single picture. Note the Orion capsule is nearly double the size of the Apollo capsule in mass. But rather than making Orion’s Service Module twice as big as the Apollo Service Module, as it should be to get similar performance, instead it is </span><i style="font-size: large;">smaller</i><span style="font-size: large;"> by 1/3rd</span><i style="font-size: large;">.</i></div><p><span style="font-size: medium;"> Orion’s service module is based on ESA’s ATV cargo tug to the ISS, which had a 4.5 meter diameter and a 10 ton propellant load.</span></p><p><span style="font-size: medium;">BUT THERE WAS NO REASON TO KEEP IT AT THAT SAME DIAMETER FOR THE ORION USE, NOR TO KEEP THE SAME SIZE PROPELLANT LOAD.</span></p><p><span style="font-size: medium;"> If instead the diameter was made to match the capsule’s diameter, as was the case with Apollo, there would be an additional 20 cubic meters of volume inside the Service Module, well more than enough to hold an additional 10 tons of the storable propellant used.</span></p><p><span style="font-size: medium;">And that is all that is needed to solve THE major problem of the SLS/Orion approach: the fact it can’t send the Orion and a lunar lander to low lunar orbit, and bring the Orion back to Earth again.</span></p><p><span style="font-size: medium;"> It is because of that the idea of the lunar Gateway was proposed, where the SLS would only have to take the Orion to a further out orbit.</span></p><p><span style="font-size: medium;"> But if instead the Service Module was given that additional 10 tons of propellant then it could send both the Orion and a ca. 15 ton lunar lander to low lunar orbit, and have enough propellant left over to bring the Orion back to Earth, a la the Apollo architecture.</span></p><p><span style="font-size: medium;"> Rarely, has a mistake been so clearly exposed, especially when its solution is so clearly made apparent as well.</span></p><p style="text-align: left;"><span style="font-size: medium;"> In the blog posts, "<a href="https://exoscientist.blogspot.com/2022/08/esa-needs-to-save-nasas-moon-plans.html" target="_blank">ESA Needs to Save NASA's Moon Plans</a>", and "<a href="https://exoscientist.blogspot.com/2022/10/possibilities-for-single-launch.html" target="_blank">Possibilities for a single launch architecture of the Artemis missions</a>", I wrote about getting a single launch format for the Artemis lunar lander missions by using the Ariane 5 as an upper stage or by using two Centaur V stages as the upper stage for the SLS, respectively.</span></p><p style="text-align: left;"><span style="font-size: medium;"> This stemmed from dislike of the plan NASA was endorsing of using multiple flights and refuelings of the SpaceX Starship as the lander. I also objected to the high cost projected for the planned Boeing Exploration Upper Stage(EUS), <a href="https://twitter.com/13ericralph31/status/1468753626873012225?s=20" target="_blank">being nearly half the cost of the entire SLS per flight, nearly $1 billion.</a></span></p><p style="text-align: left;"><span style="font-size: medium;"> <a href="https://www.floridatoday.com/story/tech/science/space/2022/12/13/now-that-nasas-artemis-i-mission-is-finished-heres-whats-next/69719716007/" target="_blank">However, NASA has negotiated a better price structure for the EUS.</a> And it appears NASA is wedded to the Boeing EUS. Then I'll discuss a single launch architecture using the Boeing EUS upper stage.</span></p><p style="text-align: left;"><span style="font-size: medium;"> The payload to LEO of this version of the SLS with the Boeing EUS, which is version Block 1B, will be 105 tons to LEO. The current fueled mass of the Orion+Service Module is 26.5 tons. An additional 10 tons of propellant will bring it to 36.5 tons. </span></p><p style="text-align: left;"><span style="font-size: medium;"> In the blog post, "<a href="https://exoscientist.blogspot.com/2022/11/a-low-cost-lightweight-lunar-lander.html" target="_blank">A low cost, lightweight lunar lander</a>", I discussed a lunar lander at a 13-ton total fueled mass based on the Cygnus capsule given life support as the crew module, and the Ariane 5 EPS storable propellant stage as the propulsive stage for the lander.</span></p><h4 style="text-align: left;"><u><span style="font-size: medium;">Calculations for the delta-v to the Moon and back.</span></u></h4><p style="text-align: left;"><span style="font-family: inherit; font-size: medium;"><span style="background-color: white; color: #222222;"> The </span><a href="https://en.wikipedia.org/wiki/Orion_(spacecraft)" style="background-color: white; color: #2288bb; text-decoration-line: none; text-decoration: none;" target="_blank">Orion with its fully fueled service module</a><span style="background-color: white; color: #222222;"> </span><span style="background-color: white; color: #222222;">has a mass of 26.5 tons. The propellant load of the service module is ~10 tons, with 16.5 total tons dry mass of the Orion and service module. We'll add an additional 10 tons propellant to the service module to bring the total mass to 36.5 tons, including 20 tons of propellant.</span></span></p><div class="separator" style="background-color: white; clear: both; color: #222222;"><span style="font-size: medium;"><span style="font-family: inherit;"> <a href="https://en.wikipedia.org/wiki/AJ10" style="color: #2288bb; text-decoration-line: none; text-decoration: none;" target="_blank">The AJ-10 engine used has a vacuum ISP of 319s.</a> We'll assume a fueled lunar lander of size ~13 tons, as described in</span><span style="font-family: inherit;"><span style="background-color: transparent;"> the blog post, "</span><a href="https://exoscientist.blogspot.com/2022/11/a-low-cost-lightweight-lunar-lander.html" style="background-color: transparent;" target="_blank">A low cost, lightweight lunar lander</a><span style="background-color: transparent;">", </span></span>comparable in size to the Apollo missions lunar lander. <span style="font-family: inherit;">So, a 16.5 + 13 = 29.5 ton mass for the vehicles that need to be put in low lunar orbit. But remember also we need to have some propellant left over in the service module to bring the Orion back home to Earth.</span></span></div><div class="separator" style="background-color: white; clear: both; color: #222222; font-size: 13.2px;"><span style="font-size: medium;"><span style="font-family: inherit;"><br /></span></span></div><div class="separator" style="background-color: white; clear: both; color: #222222; font-size: 13.2px;"><span style="font-size: medium;"><span style="font-family: inherit;"> For the delta-v calculation, after the SLS places the Orion/Service Module/lunar lander stack in trans-lunar injection(TLI) towards the Moon, we need 0.9 km/s to put the stack into low lunar orbit. This requires 13 tons of propellant, leaving 7 tons remaining:</span></span></div><div class="separator" style="background-color: white; clear: both; color: #222222; font-size: 13.2px;"><span style="font-size: medium;"><span style="font-family: inherit;">319*9.81Ln(1 + 13/(29.5 +7)) = 0.950 km/s. The lunar lander will then be launched to land on the Moon while the Orion and service module remain in lunar orbit.</span></span></div><div class="separator" style="background-color: white; clear: both; color: #222222; font-size: 13.2px;"><span style="font-size: medium;"><span style="font-family: inherit;"><br /></span></span></div><div class="separator" style="background-color: white; clear: both; color: #222222; font-size: 13.2px;"><span style="font-size: medium;"><span style="font-family: inherit;"> After the lander mission is completed, the lander returns the astronauts to the Orion in lunar orbit, and the lander is then jettisoned. The Orion's service module is then fired to bring the Orion back to Earth. After lander jettison, the dry mass of the Orion and service module will be 16.5 tons. Then the 7 tons of remaining propellant is sufficient to perform the trans-Earth injection(TEI) burn of 900 m/s to escape lunar orbit and place the spacecraft back onto the free return trajectory back to Earth:</span></span></div><p style="text-align: left;"><span style="font-size: medium;"><span style="background-color: white; color: #222222;"><span style="font-family: inherit;">319*9.81Ln(1 + 7/16.5) = 1,100 m/s</span></span><span face="Arial, Tahoma, Helvetica, FreeSans, sans-serif" style="background-color: white; color: #222222;">.</span> </span></p><p style="text-align: left;"><span style="font-size: medium;"> So the total mass that needs to be sent to trans lunar injection(TLI) on a path to encounter the Moon is 36.5 + 13 = 49.5 tons. Now use the rule-of-thumb that a Centaur-like hydrolox stage can send to TLI at a 3,000 m/s required delta-v a payload mass equal to its propellant load.</span></p><p style="text-align: left;"><span style="font-size: medium;"> So use for a third stage atop the Boeing EUS the Centaur V at an 50 ton propellant load and 5 ton dry mass. This then results in a total mass to LEO of 104.5 tons consisting of the 55 tons of the Centaur V plus the 49.5 tons of the Orion capsule/Service Module/lunar lander, within the lift capacity of the SLS Block 1B to LEO.</span></p><p style="text-align: left;"><span style="font-size: medium;"><br /></span></p><p style="text-align: left;"><span style="font-size: medium;"> Robert Clark</span></p>Robert Clarkhttp://www.blogger.com/profile/16114043697010364282noreply@blogger.com1tag:blogger.com,1999:blog-7598615455712402973.post-33161531408607867202023-08-04T15:47:00.000-04:002023-08-04T15:47:49.407-04:00U.S. will lag behind in utilization of resources on the Moon.<p style="text-align: center;"><i> Copyright 2023 Robert Clark</i></p><p style="text-align: center;"><i><br /></i></p><p> Quite annoying that NASA won’t be including any instruments on the VIPER lander at the lunar South pole to detect heavy metals, only ones for detecting water and light elements. Nor will the Astrobotic Peregrine commercial lander. </p><p> The LCROSS mission provided tantalizing hints of valuable metals from its orbital observations: </p>Moon Blast Reveals Lunar Surface Rich With Compounds. <br />Science Oct 21, 2010 2:05 PM EDT.<br /><i>There is water on the moon … along with a long list of other compounds, including, mercury, gold and silver. That’s according to a more detailed analysis of the chilled lunar soil near the moon’s South Pole, released as six papers by a large team of scientists in the journal, Science Thursday.</i><br /><a href="https://www.pbs.org/newshour/science/its-confirmed-there-is-water">https://www.pbs.org/newshour/science/its-confirmed-there-is-water</a><p> And a Japanese lunar orbiter gave indications of uranium: </p>Uranium could be mined on the Moon. Uranium could one day be mined on the Moon after a Japanese spacecraft discovered the element on its surface.<br />By Julian Ryall in Tokyo 4:58PM BST 01 Jul 2009.<br /><i>The space probe Kaguya detected the radioactive element in samples of the Moon's surface with a gamma-ray spectrometer, along with thorium, potassium, magnesium, silicon, calcium, titanium and iron.<br />The discovery opens up the possibility of mining operations on a commercial basis or even nuclear power plants being constructed on the Moon.</i><br /><a href="https://web.archive.org/web/20110423155534/http://www.telegraph.co.uk/science/space/5711129/Uranium-could-be-mined-on-the-Moon.html">https://web.archive.org/web/20110423155534/http://www.telegraph.co.uk/science/space/5711129/Uranium-could-be-mined-on-the-Moon.html</a><div><br /></div><div> Note that one of the locations the urianium was detected was the mysterious South Pole Aitken impact basin.<br /><p> The later Surveyor landers to the Moon by NASA since the 60’s all contained x-ray spectrometers(XRF) for detecting heavy elements. And all of the Mars landers since the Viking landers in the 70’s either had XRF spectrometers or more accurate alpha-proton x-ray spectrometers(APXS) for detecting heavy elements.</p><p> Moreover, both the just launched Indian lunar south polar lander and Chinese lander to lunar south pole will contain a detector for heavy elements.</p><p>The upcoming lunar lander from Japan will also include an X-ray spectrometer for detecting heavy metals:</p>Japan gearing up to launch small moon lander next month.<br />By Andrew Jones published about 17 hours ago.<br />SLIM is scheduled to lift off on Aug. 25.<br /><i>Also joining the lunar ride will be the X-ray Imaging and Spectroscopy Mission, or XRISM, a JAXA-NASA collaborative mission that also involves participation from the European Space Agency.</i><br /><a href="https://www.space.com/japan-slim-moon-lander-launch-august-2023">https://www.space.com/japan-slim-moon-lander-launch-august-2023</a><br /><p> This lander will not be to the lunar South Pole but this still confirms the point that every other lander to ANY space body, including asteroids and comets, always contains detectors for measuring heavy elements.</p><p>Even the little Sojouner rover on the Mars Pathfinder mission had its own alpha-proton x-ray(APXS) spectrometer for measuring heavy elements:</p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjEjPZ22LfwmpJNcOoOaGpl5-bBu7R0G0jb7KJUOzjIEAvPkTIiWmaO9plJEm-HRMWReFyORESUohS1oSICLSULpdDiYijsa9nvaZ0_lnVJ3JD_iI2UDGgqVvFm0Wf1jZtPmi_4y8ypioB39CCHZXyn9M-wUNSB6DR8XPpnJQTdw-UtnY-UByTkPMGmW2Q/s1922/Sojourner%20rover%20APXS.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1922" data-original-width="1472" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjEjPZ22LfwmpJNcOoOaGpl5-bBu7R0G0jb7KJUOzjIEAvPkTIiWmaO9plJEm-HRMWReFyORESUohS1oSICLSULpdDiYijsa9nvaZ0_lnVJ3JD_iI2UDGgqVvFm0Wf1jZtPmi_4y8ypioB39CCHZXyn9M-wUNSB6DR8XPpnJQTdw-UtnY-UByTkPMGmW2Q/w490-h640/Sojourner%20rover%20APXS.jpg" width="490" /></a></div><p> The APXS is the round instrument in front.</p><p> The Sojourner rover only weighed 25 lbs, 11 kg, and only needed 15 watts to run on, which can be supplied by a few oz of rechargeable lithium batteries. So the weight and power requirements for the APXS instrument itself would have been much smaller than that still.</p><p> It’s really unfathomable that the U.S.’s landers VIPER and Astrobotic Peregrine to the lunar South Pole will be the only ones to ANY space body, probably numbering into the couple of dozen now, that won’t have instruments for detecting heavy elements.</p><p></p><p> There’s no guarantee that India or China will share with the U.S. the discovery by their landers of valuable metals or other minerals on the Moon. They would probably figure if the U.S. didn’t see the importance of including such instruments on their own missions to the lunar South Pole, then that’s their problem.</p><p> These landers to the lunar south pole may return literally world-changing results. There has been speculation that the <a href="https://www.smithsonianmag.com/smart-news/asteroid-16-psyche-may-be-worth-more-than-planet-earth-at-10-quintillion-in-fine-metals-180979303/" target="_blank">metal containing asteroid Psyche may contain many trillions of dollars of valuable metals.</a></p><p> Then in this regard quite notable is this:</p>Weird 'Anomaly' at the Moon's South Pole May Be a Metal Asteroid's Grave<br />By Meghan Bartels published June 10, 2019<br /><a href="https://www.space.com/moon-south-pole-anomaly-metal-asteroid-impact.html">https://www.space.com/moon-south-pole-anomaly-metal-asteroid-impact.html</a><p> I mentioned at least two independent orbital missions that observed valuable minerals specifically at the lunar South Pole, LCROSS and Kaguya. This article concerns another lunar orbital mission mission, GRAIL, measuring gravity variations on the Moon, that found intense gravity at the South Pole Aitken impact basin. The researchers suggested it was from the impact of a large asteroid, actually a Ceres-sized dwarf planet, emplacing heavy metals there. If so, then it conceivably could have been an asteroid of the Psyche-type containing trillions of dollars of valuable metals.</p><p> Conceivably, the trillions of dollars of valuable metals speculated to be on Psyche could already be just next door!</p><p><br /></p><p> Robert Clark</p></div>Robert Clarkhttp://www.blogger.com/profile/16114043697010364282noreply@blogger.com0tag:blogger.com,1999:blog-7598615455712402973.post-21387779530283865392023-07-18T13:31:00.001-04:002023-07-18T14:34:07.836-04:00Potential Game-Changer for Generating Propellant on Mars.<p style="text-align: center;"> <i>Copyright 2023 Robert Clark</i></p><p style="text-align: center;"><br /></p><p> As an educator it’s quite exciting that an important unsolved problem may be one university or high school students, or even amateur scientists can address.</p><p> A possibly limiting technology for a manned Mars mission is the high energy requirements to produce the return propellant on Mars. Robert Zubrin estimated for a Starship-sized vehicle as it requiring possibly 10 football fields worth of solar panels, or possibly even a nuclear reactor placed on Mars:</p>Elon Musk’s Plan to Settle Mars Robert Zubrin.<br /><a href="https://www.yahoo.com/news/elon-musk-plan-settle-mars-093002155.html">https://www.yahoo.com/news/elon-musk-plan-settle-mars-093002155.html</a><p> Marcus House in his video series also discusses the problem:</p><p> SpaceX Starship can return from Mars without surface refilling.</p><p></p><div class="separator" style="clear: both; text-align: center;"><iframe allowfullscreen="" class="BLOG_video_class" height="266" src="https://www.youtube.com/embed/u55zpE4r-_Y" width="320" youtube-src-id="u55zpE4r-_Y"></iframe></div><p></p><p>Slide from the video showing proposed size of Mars solar panels for ISRU propellant production:</p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgRZ2bxv1DxuhGRq98pg6oBzPUwAlzZ3W_pf-3M9W6XbhNjxJ3O3kS5L5pObHko9GjX0jcUTeilRunsgVSU8sgyT7xpy0kb02HjEpysxE6OSDKe2GYmFDz4eFCPYmqyIBaybyoXIBhw30cYnd0FO764HtHeugvdugVjvDQvNSyAA75P_IFunEasiv7F9cM/s2160/2-DB263-CC-E364-40-DF-BD8-D-AF8779-F38-DF3.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1620" data-original-width="2160" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgRZ2bxv1DxuhGRq98pg6oBzPUwAlzZ3W_pf-3M9W6XbhNjxJ3O3kS5L5pObHko9GjX0jcUTeilRunsgVSU8sgyT7xpy0kb02HjEpysxE6OSDKe2GYmFDz4eFCPYmqyIBaybyoXIBhw30cYnd0FO764HtHeugvdugVjvDQvNSyAA75P_IFunEasiv7F9cM/w640-h480/2-DB263-CC-E364-40-DF-BD8-D-AF8779-F38-DF3.png" width="640" /></a></div><p> </p><p> Beginning at about the 12 minute point, House runs the numbers and considers it so daunting, at least for initial missions, that he suggests it might be better instead to transport the propellant from Earth with Starship tanker flights all the way to Mars. This of course discounts the entire advantage of using Mars generated propellant to achieve a smaller mission size.</p><p> The problem is the method envisioned would be by either splitting CO2 into carbon and oxygen and/or H2O into hydrogen and oxygen by electrolysis to be used for the propellant. However, these are energy intensive operations, which explains why in the reverse direction you get so much energy out when you combine them for combustion.</p><p> What the researchers for this new idea are proposing instead is getting the oxygen for Mars atmosphere by filtering out the <i>free</i> O2 already there:</p>Feb 19, 2022<br />Breathing Mars Air: Stationary and Portable O2 Generation.<br />Ivan Ermanoski<br />Arizona State University<br /><i>The basis for TSSD is a two-step thermally-driven cycle operating below ~260 C. thermal swing sorption/desorption (TSSD)--to generate oxygen from the Mars atmosphere with 10x less energy than the state of the art. Our approach is motivated by thermodynamics: the minimum theoretical work to separate oxygen from the Mars atmosphere is ~30-50 times lower than to obtain it by splitting carbon dioxide.<br />Efficiency: TSSD is expected to be ~10x more efficient than MOXIE. For MOXIE, the target power requirement for oxygen propellant production is 30 kW. The TSSD estimate is only 4 kW; i.e., 90% less than MOXIE. Applying TSSD in rovers, the estimated power for oxygen pro-duction is only ~50 W/person.</i><br /><a href="https://www.nasa.gov/directorates/spacetech/niac/2022/Breathing_Mars_Air/">https://www.nasa.gov/directorates/spacetech/niac/2022/Breathing_Mars_Air/</a><br /><p> Here’s the breakdown of the Martian atmosphere:</p>Atmosphere of Mars. General information[2]<br />Average surface pressure 610 Pa (0.088 psi; 4.6 mmHg; 0.0060 atm)<br />Mass 2.5x1016 kg[1]<br />Composition[3][4]<br />Carbon dioxide 95%<br />Nitrogen 2.8%<br />Argon 2%<br /><b>Oxygen 0.174%<br />Carbon monoxide 0.0747%</b><br />Water vapor 0.03% (variable)<br /><a href="https://en.wikipedia.org/wiki/Atmosphere_of_Mars">https://en.wikipedia.org/wiki/Atmosphere_of_Mars</a><br /><p> The authors so far are proposing just getting <span style="background-color: white; color: #212529;">O</span><span style="background-color: white; bottom: -0.25em; box-sizing: border-box; color: #212529; line-height: 0; position: relative; vertical-align: baseline;">2</span> from the Martian air. But note there is also free carbon monoxide(CO) in its atmosphere. Then it may also be possible to filter out CO from Mars air. This is quite important because CO can be made to combust with <span class="mord mathnormal" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; border: 0px; box-sizing: border-box; color: #222222; font-family: "Times New Roman", serif; font-size: 18px; letter-spacing: -0.5px; margin: 0px 0.02778em 0px 0px; outline: 0px; padding: 0px; position: static; white-space: nowrap;">O</span><span class="msupsub" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; border: 0px; box-sizing: border-box; color: #222222; display: inline-block; font-family: "Times New Roman", serif; font-size: 18px; letter-spacing: -0.5px; margin: 0px; outline: 0px; padding: 2px 0px; position: relative; white-space: nowrap;"><span class="vlist-t vlist-t2" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; border-collapse: collapse; border: 0px; box-sizing: border-box; display: inline-table; margin: 0px -2px 0px 0px; outline: 0px; padding: 0px; position: static; table-layout: fixed;"><span class="vlist-r" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; border: 0px; box-sizing: border-box; display: table-row; margin: 0px; outline: 0px; padding: 0px; position: static;"><span class="vlist" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; border: 0px; box-sizing: border-box; display: table-cell; height: 0.301108em; margin: 0px; outline: 0px; padding: 0px; position: relative; vertical-align: bottom;"><span style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; border: 0px; box-sizing: border-box; display: block; height: 0px; margin: 0px 0.05em 0px -0.02778em; outline: 0px; padding: 0px; position: relative; top: -2.55em;"><span class="pstrut" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; border: 0px; box-sizing: border-box; display: inline-block; height: 2.7em; margin: 0px; outline: 0px; overflow: hidden; padding: 0px; position: static; width: 0px;"></span><span class="sizing reset-size6 size3 mtight" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; border: 0px; box-sizing: border-box; display: inline-block; font-size: 0.7em; margin: 0px; outline: 0px; padding: 0px; position: static;"><span class="mord mtight" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; border: 0px; box-sizing: border-box; font-size: 12.6px; margin: 0px; outline: 0px; padding: 0px; position: static;">2</span></span></span></span></span></span></span>:</p><p><span class="base" style="background: rgb(255, 255, 255); border: 0px; box-sizing: border-box; color: #222222; display: inline-block; font-family: "Times New Roman", serif; font-size: 18px; letter-spacing: -0.5px; margin: 0px; outline: 0px; padding: 0px; position: relative; white-space: nowrap; width: min-content;"><span class="mord" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">1.)2</span><span class="mord mathnormal" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px 0.07153em 0px 0px; outline: 0px; padding: 0px; position: static;">C</span><span class="mord mathnormal" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px 0.02778em 0px 0px; outline: 0px; padding: 0px; position: static;">O</span><span class="mspace" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; margin: 0px 0.222222em 0px 0px; outline: 0px; padding: 0px; position: static;"></span><span class="mbin" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">+</span><span class="mspace" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; margin: 0px 0.222222em 0px 0px; outline: 0px; padding: 0px; position: static;"></span></span><span class="base" style="background: rgb(255, 255, 255); border: 0px; box-sizing: border-box; color: #222222; display: inline-block; font-family: "Times New Roman", serif; font-size: 18px; letter-spacing: -0.5px; margin: 0px 0px 3px; outline: 0px; padding: 0px; position: relative; white-space: nowrap; width: min-content;"><span class="strut" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; height: 0.83333em; margin: 0px; outline: 0px; padding: 0px; position: static; vertical-align: -0.15em;"></span><span class="mord" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;"><span class="mord mathnormal" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px 0.02778em 0px 0px; outline: 0px; padding: 0px; position: static;">O</span><span class="msupsub" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; margin: 0px; outline: 0px; padding: 2px 0px; position: relative;"><span class="vlist-t vlist-t2" style="background: transparent; border-collapse: collapse; border: 0px; box-sizing: border-box; display: inline-table; margin: 0px -2px 0px 0px; outline: 0px; padding: 0px; position: static; table-layout: fixed;"><span class="vlist-r" style="background: transparent; border: 0px; box-sizing: border-box; display: table-row; margin: 0px; outline: 0px; padding: 0px; position: static;"><span class="vlist" style="background: transparent; border: 0px; box-sizing: border-box; display: table-cell; height: 0.301108em; margin: 0px; outline: 0px; padding: 0px; position: relative; vertical-align: bottom;"><span style="background: transparent; border: 0px; box-sizing: border-box; display: block; height: 0px; margin: 0px 0.05em 0px -0.02778em; outline: 0px; padding: 0px; position: relative; top: -2.55em;"><span class="pstrut" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; height: 2.7em; margin: 0px; outline: 0px; overflow: hidden; padding: 0px; position: static; width: 0px;"></span><span class="sizing reset-size6 size3 mtight" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; font-size: 0.7em; margin: 0px; outline: 0px; padding: 0px; position: static;"><span class="mord mtight" style="background: transparent; border: 0px; box-sizing: border-box; font-size: 12.6px; margin: 0px; outline: 0px; padding: 0px; position: static;"><span class="mord mtight" style="background: transparent; border: 0px; box-sizing: border-box; font-size: 12.6px; margin: 0px; outline: 0px; padding: 0px; position: static;">2</span></span></span></span></span><span class="vlist-s" style="background: transparent; border: 0px; box-sizing: border-box; display: table-cell; font-size: 1px; margin: 0px; min-width: 2px; outline: 0px; padding: 0px; position: static; vertical-align: bottom; width: 2px;"></span></span><span class="vlist-r" style="background: transparent; border: 0px; box-sizing: border-box; display: table-row; margin: 0px; outline: 0px; padding: 0px; position: static;"><span class="vlist" style="background: transparent; border: 0px; box-sizing: border-box; display: table-cell; height: 0.15em; margin: 0px; outline: 0px; padding: 0px; position: relative; vertical-align: bottom;"><span style="background: transparent; border: 0px; box-sizing: border-box; display: block; height: 0px; margin: 0px; outline: 0px; padding: 0px; position: relative;"></span></span></span></span></span></span><span class="mspace" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; margin: 0px 0.277778em 0px 0px; outline: 0px; padding: 0px; position: static;"></span><span class="mrel" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">→</span><span class="mspace" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; margin: 0px 0.277778em 0px 0px; outline: 0px; padding: 0px; position: static;"></span></span><span class="base" style="background: rgb(255, 255, 255); border: 0px; box-sizing: border-box; color: #222222; display: inline-block; font-family: "Times New Roman", serif; font-size: 18px; letter-spacing: -0.5px; margin: 0px 0px 3px; outline: 0px; padding: 0px; position: relative; white-space: nowrap; width: min-content;"><span class="strut" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; height: 0.87777em; margin: 0px; outline: 0px; padding: 0px; position: static; vertical-align: -0.19444em;"></span><span class="mord" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">2</span><span class="mord mathnormal" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px 0.07153em 0px 0px; outline: 0px; padding: 0px; position: static;">C</span><span class="mord" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;"><span class="mord mathnormal" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px 0.02778em 0px 0px; outline: 0px; padding: 0px; position: static;">O</span><span class="msupsub" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; margin: 0px; outline: 0px; padding: 2px 0px; position: relative;"><span class="vlist-t vlist-t2" style="background: transparent; border-collapse: collapse; border: 0px; box-sizing: border-box; display: inline-table; margin: 0px -2px 0px 0px; outline: 0px; padding: 0px; position: static; table-layout: fixed;"><span class="vlist-r" style="background: transparent; border: 0px; box-sizing: border-box; display: table-row; margin: 0px; outline: 0px; padding: 0px; position: static;"><span class="vlist" style="background: transparent; border: 0px; box-sizing: border-box; display: table-cell; height: 0.301108em; margin: 0px; outline: 0px; padding: 0px; position: relative; vertical-align: bottom;"><span style="background: transparent; border: 0px; box-sizing: border-box; display: block; height: 0px; margin: 0px 0.05em 0px -0.02778em; outline: 0px; padding: 0px; position: relative; top: -2.55em;"><span class="pstrut" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; height: 2.7em; margin: 0px; outline: 0px; overflow: hidden; padding: 0px; position: static; width: 0px;"></span><span class="sizing reset-size6 size3 mtight" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; font-size: 0.7em; margin: 0px; outline: 0px; padding: 0px; position: static;"><span class="mord mtight" style="background: transparent; border: 0px; box-sizing: border-box; font-size: 12.6px; margin: 0px; outline: 0px; padding: 0px; position: static;"><span class="mord mtight" style="background: transparent; border: 0px; box-sizing: border-box; font-size: 12.6px; margin: 0px; outline: 0px; padding: 0px; position: static;">2</span></span></span></span></span><span class="vlist-s" style="background: transparent; border: 0px; box-sizing: border-box; display: table-cell; font-size: 1px; margin: 0px; min-width: 2px; outline: 0px; padding: 0px; position: static; vertical-align: bottom; width: 2px;"></span></span><span class="vlist-r" style="background: transparent; border: 0px; box-sizing: border-box; display: table-row; margin: 0px; outline: 0px; padding: 0px; position: static;"><span class="vlist" style="background: transparent; border: 0px; box-sizing: border-box; display: table-cell; height: 0.15em; margin: 0px; outline: 0px; padding: 0px; position: relative; vertical-align: bottom;"><span style="background: transparent; border: 0px; box-sizing: border-box; display: block; height: 0px; margin: 0px; outline: 0px; padding: 0px; position: relative;"></span></span></span></span></span></span><span class="mpunct" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">;</span><span class="mspace" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; margin: 0px 0.166667em 0px 0px; outline: 0px; padding: 0px; position: static;"></span><span class="mord" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">Δ</span><span class="mord mathnormal" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px 0.08125em 0px 0px; outline: 0px; padding: 0px; position: static;">H</span><span class="mspace" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; margin: 0px 0.277778em 0px 0px; outline: 0px; padding: 0px; position: static;"></span><span class="mrel" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">=</span><span class="mspace" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; margin: 0px 0.277778em 0px 0px; outline: 0px; padding: 0px; position: static;"></span></span><span class="base" style="background: rgb(255, 255, 255); border: 0px; box-sizing: border-box; color: #222222; display: inline-block; font-family: "Times New Roman", serif; font-size: 18px; letter-spacing: -0.5px; margin: 0px 0px 3px; outline: 0px; padding: 0px; position: relative; white-space: nowrap; width: min-content;"><span class="strut" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; height: 1em; margin: 0px; outline: 0px; padding: 0px; position: static; vertical-align: -0.25em;"></span><span class="mord" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">−</span><span class="mord" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">5</span><span class="mord" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">6</span><span class="mord" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">9</span><span class="mord mathnormal" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px 0.03148em 0px 0px; outline: 0px; padding: 0px; position: static;">k</span><span class="mord mathnormal" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px 0.09618em 0px 0px; outline: 0px; padding: 0px; position: static;">J</span><span class="mord" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">/</span><span class="mord mathnormal" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">m</span><span class="mord mathnormal" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">o</span><span class="mord mathnormal" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px 0.01968em 0px 0px; outline: 0px; padding: 0px; position: static;">l</span></span></p><p><span style="color: #222222;"> However, when CO can be obtained from low energy filtration from the Martian atmosphere then free hydrogen for propulsion can be obtained by the reaction:</span></p><span style="background-color: white; color: #212529; font-family: verdana;">2.)CO + H</span><span style="background-color: white; bottom: -0.25em; box-sizing: border-box; color: #212529; font-family: verdana; line-height: 0; position: relative; vertical-align: baseline;">2</span><span style="background-color: white; color: #212529; font-family: verdana;">O → CO</span><span style="background-color: white; bottom: -0.25em; box-sizing: border-box; color: #212529; font-family: verdana; line-height: 0; position: relative; vertical-align: baseline;">2</span><span style="background-color: white; color: #212529; font-family: verdana;">+ H</span><span style="background-color: white; bottom: -0.25em; box-sizing: border-box; color: #212529; font-family: verdana; line-height: 0; position: relative; vertical-align: baseline;">2, </span><span style="background-color: #fbfaf5; color: #666666; font-family: verdana; white-space: pre;">Δ</span><span style="background-color: white; color: #212529; font-family: verdana; white-space: pre;">H = -41 kJ/mol</span><span style="background-color: white; color: #212529; font-family: verdana;"> </span><div><p> This uses water that both orbiters and landers have shown to be wide spread on Mars even in low latitude locations in ice form. </p><p><span style="color: #222222;">You can then get methane, if that is the preferred fuel over hydrogen, by reacting the free hydrogen with CO2 by the famous Sabatier reaction:</span></p><p><span class="mwe-math-element" style="background-color: white; color: #202122; font-family: verdana; font-size: 14px;">3.)<img alt="{\displaystyle {\ce {CO2{}+4H2->[{} \atop 400\ ^{\circ }{\ce {C}}][{\ce {pressure+catalyst}}]CH4{}+2H2O}}}" aria-hidden="true" class="mwe-math-fallback-image-inline" src="https://wikimedia.org/api/rest_v1/media/math/render/svg/9954c5b345addcf6421c02b5becd4db9e4dde1c8" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; border: 0px; box-shadow: rgba(0, 0, 0, 0.1) 1px 1px 5px; display: inline-block; height: 6.509ex; margin-bottom: -0.646ex; margin-top: -0.398ex; padding: 5px; vertical-align: -2.359ex; width: 40.514ex;" /></span><span style="background-color: white; color: #202122; font-family: verdana; font-size: 14px; padding-left: 1em;"> </span><span style="background-color: white; color: #202122; font-family: verdana; font-size: 14px;">∆</span><i style="background-color: white; color: #202122; font-family: sans-serif; font-size: 14px;">H</i><span style="background-color: white; color: #202122; font-family: verdana; font-size: 14px;"> = −165.0 kJ/mol</span></p><p> </p><p> The nice thing about this proposal is that any decent high school or university lab or even well-appointed amateur lab can test it out themselves. Key question: what is the method requiring least energy to concentrate and filter out the <span style="background-color: white; color: #212529;">O</span><span style="background-color: white; bottom: -0.25em; box-sizing: border-box; color: #212529; line-height: 0; position: relative; vertical-align: baseline;">2</span> and CO when in the concentrations known in the Martian atmosphere?</p><p> About how to filter out the <span style="background-color: white; color: #212529;">O</span><span style="background-color: white; bottom: -0.25em; box-sizing: border-box; color: #212529; line-height: 0; position: relative; vertical-align: baseline;">2</span> and CO, three possibilities come to mind:</p><p>1.)Gas centrifuge separation.</p><p>2.)Fractional distillation.</p><p>3.)Membrane separation.</p><p> As discussed here: <a href="https://en.m.wikipedia.org/wiki/Air_separation">https://en.m.wikipedia.org/wiki/Air_separation</a></p><p><b> Of game-changing importance is that rather than football fields of solar cells or even a nuclear power plant being needed to generate the propellant, it may be the process of producing the propellant actually generates power.</b></p><p> But if this is so easy, why has this not been done before? Mars atmosphere is almost all CO2, so the obvious thing to investigate is getting <span style="background-color: white; color: #212529;">O</span><span style="background-color: white; bottom: -0.25em; box-sizing: border-box; color: #212529; line-height: 0; position: relative; vertical-align: baseline;">2</span> by splitting CO2 into carbon and O2 by electrolysis.</p><p> On the other hand, <span style="background-color: white; color: #212529;">O</span><span style="background-color: white; bottom: -0.25em; box-sizing: border-box; color: #212529; line-height: 0; position: relative; vertical-align: baseline;">2</span> is only a little more than 1/1000th of Mars atmosphere, which itself is only 1/100ths Earth’s air density. So the oxygen there would be in the range of only 1/100,000th the density we normally see on Earth. So this would require an extreme level of densification to be usable.</p><p> However, in this regard, it may be sufficient to just cool the oxygen to liquid form which is needed for the propellant application anyway. This might not require too high energy input since at night the temperatures drop to well below freezing on Mars. </p><p> The most optimal generation and separation/filtration methods have to take into account the conditions on Mars. For instance in eq. (2.) the energy released of -41 kJ/mol is when the water is in gaseous form. It's much less if it is liquid or frozen water form. But in this regard it is notable temperatures on Mars surface do reach above the melting point of water on large swaths of Mars during the the mid afternoon hours on Mars.</p><div> It had been frequently said that liquid water can not exist on Mars because Mars landers had shown the <i>air</i> temperatures were always below freezing. But what was missed was the actual <i>surface</i> temperatures were often well above the air temperatures. This is a rather obvious point that's easily understood when you compare for example on Earth the temperature of the air on a hot Summer day with what the temperature on the ground might be, especially if the ground is a dark surface absorbing sunlight rather than reflecting it. See the graphs from the Spirit and Opportunity MER rovers:</div></div><div><br /></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgPLhT4sxSBsR4PkaGFlX9RAs_ltpYMKhdNOorFKF6BiAS8O6r80e1DdUx8_kO1PPNrGa-d0CnTjrJKq7E2a3o9dciRICLnoqJWGtG5zyCaWPfIhvdyi5JKx4syrpkQoAn1P53CmfVlAmmavPKD_RfMIkX1HX65KSlCvQ_gFHbyiavA9FOLBYsr0OIDZvI/s680/FvG8HWUWcAEG-nK.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="680" data-original-width="510" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgPLhT4sxSBsR4PkaGFlX9RAs_ltpYMKhdNOorFKF6BiAS8O6r80e1DdUx8_kO1PPNrGa-d0CnTjrJKq7E2a3o9dciRICLnoqJWGtG5zyCaWPfIhvdyi5JKx4syrpkQoAn1P53CmfVlAmmavPKD_RfMIkX1HX65KSlCvQ_gFHbyiavA9FOLBYsr0OIDZvI/w480-h640/FvG8HWUWcAEG-nK.jpg" width="480" /></a></div> But because of the low atmospheric pressure the time at which the water will remain liquid is relatively short, even if the ground temperature will be above the melting point for hours. This is good for our propellant generation purposes though since we will get the water in gaseous form without additionally adding energy.<br /><div> </div><h3 style="text-align: left;"> Hydrogen fuel from Mars to Earth?</h3><div> The propellant generation from taking atmospheric oxygen and carbon monoxide might actually <i>generate</i> energy. But this means we could actually produce hydrogen and methane at low cost, unlike the electrolysis methods that require high energy input. This shows the importance of this in general not just for Mars. It could be a means of producing clean energy in the form of hydrogen being transported from Mars to Earth. Again, it is remarkable that this is something high school and university teams can contribute to establishing its feasibility.</div><div><br /></div><div> But for it to be feasible, the energy requirements for producing the O2 and CO will have to be improved. The NASA release on the new TSSD method touts its reduced energy requirements over the usual electrolysis method, MOXIE, giving its power requirements as 4 kW. But the news release doesn't say how much oxygen is produced by the process for that power. This article allows us to estimate it:</div><div><br /></div><div><div>MARCH 3, 2022 BY ANDY TOMASWICK</div><div>Mars Explorers are Going to Need air, and Lots of it. Here’s a Technology That Might Help Them Breath Easy.</div><div>...</div><div><i>All that power consumption makes for an expensive system. <b>A MOXIE machine that can create 2 kg O2 per hour (enough to support two explorers) would require around 25 kW of power</b>, or slightly less than the average American house uses per day. While that may not seem like a lot, utilizing solar energy is a much more difficult prospect on Mars. Any early solar farm built to run the MOXIE system would dwarf the habitat it could supply with oxygen for just two astronauts.</i></div><div><i><br /></i></div><div><i>Enter the TSSD, which nicely eliminates all three major problems with MOXIE. The system itself relies on a thermochemical pumping system, which relies on heat differentials to move the atmosphere to the appropriate place, eliminating the need for a mechanical pump. It also doesn’t suffer from carbon fouling as it doesn’t break apart CO2. <b>Lastly, it doesn’t require too much energy, with Dr. Ivan Ermanoski, the PI on the NIAC funded project and a research professor at Arizona State University, expecting that it will be 90% more efficient than MOXIE</b>.</i></div></div><div><a href="https://www.universetoday.com/154809/mars-explorers-are-going-to-need-air-and-lots-of-it-heres-a-technology-that-might-help-them-breath-easy/">https://www.universetoday.com/154809/mars-explorers-are-going-to-need-air-and-lots-of-it-heres-a-technology-that-might-help-them-breath-easy/</a></div><div><br /></div><div> TSSD needing 1/10th the power of MOXIE would suggest 2 kg per hour of O2 for 2,500 watts, or 1 kg per hour for 1,250 watts. The process operating at an hour would require 1,250w*3,600s = 4,500,000 joules, 4.5 MJ, of energy per kg of O2 generated.</div><div><br /></div><div> Then we also need to separate out the CO. The CO content in the Mars atmosphere is about half that of the O2 so as a first order estimate we can estimate it as taking 9,000,000 joules per kg generated, though to get the actual value would take closer examination of the whole process used to generate the O2 and how it would have to be adapted to generate the CO.</div><div><br /></div><div> To get an idea of how much total energy this is in practical terms for both O2 and CO production, equation 1.) gives the energy generated by combusting CO in O2 as 569,000 joules per mol of O2. Since O2 is 32 grams per mol, this is 569,000J/32gm = 17,800 joules/gm or 17.8 MJ per kg of O2. But the CO needed for the reaction is 2 moles for each mole of O2, and since they are close to the same molecular weight you need about 2 kg of CO for each kg of oxygen.</div><div><br /> So you need 4.5 MJ of energy to generate a kg of O2 and then 2*9 MJ = 18 MJ to generate the needed 2 kg of CO. This is a total of 22.5 MJ required to put in to get out the 17.8 MJ you would get by combusting the CO with the O2.</div><div><br /></div><div> For only producing the H2 by equation 2.), you really need only the CO but the molecular weight of the CO is 15 times that of the H2 so you would need 15 times as much CO and its high energy cost by the TSSD process for each kg of H2 produced.</div><div><i><br /></i></div><div><i> Then the major impediment for making this feasible is finding low energy methods of separating out O2 and CO at approx. 1 part per thousand concentrations from a CO2 atmosphere only 1/100th as dense as Earths.</i></div><div><br /></div><div> TSSD is about 1/10th as power intensive as the usual electrolysis method. To put this in perspective, instead of 10 footballs fields of solar cells to run the propellant generating plant for the Starship on Mars, it would only take 1 football field worth of solar cells. The energy requirements probably need to be reduced again by at least another factor of 10.</div><div><br /></div><div> Some recent advances in gas separation by absorption of surfaces might improve on the energy requirements of TSSD:</div><div><br /></div><div><div>Weird Crystal Can Absorb All The Oxygen In A Room — And Then Release It Later</div><div>This could potentially make fuel cells, space travel, and scuba diving a lot more efficient.</div><div>BY SARAH FECHT | PUBLISHED OCT 2, 2014 1:15 AM EDT</div><div>...</div><div><i>Researchers from the University of Southern Denmark say they’ve invented a crystal that pulls oxygen out of the air and even water. Apparently, just a spoonful of the stuff can suck up all the oxygen in a room.</i></div><div><i>The crystal is a salt made from cobalt*, and it appears to be capable of holding oxygen at a concentration that is 160 times higher than the air we breathe. The paper notes that “an excess” of the substance would bind up to 99 percent of the oxygen in a room.</i></div><div><i><br /></i></div><div><i>But what’s more remarkable is that the crystal can later release the oxygen when exposed to heat or low-oxygen conditions. In a press release, study author Christine McKenzie likens it to the hemoglobin in our blood, which uses iron to bind and release oxygen in the human body.</i></div><div><a href="https://www.popsci.com/article/science/weird-crystal-can-absorb-all-oxygen-room-and-then-release-it-later/">https://www.popsci.com/article/science/weird-crystal-can-absorb-all-oxygen-room-and-then-release-it-later/</a></div></div><div><br /></div><div> And:</div><div><br /></div><div><div>Nanowindows Poke Holes in Graphene</div><div>By Shinshu University | June 4, 2018</div><div><i>Unlike the windows of your house, nanoscale holes in graphene (named as “nanowindows”) can selectively choose which type of air molecules can pass through.</i></div><div><i><br /></i></div><div><i>Scientists from Shinshu University and PSL University, France, theoretically proved concerted motion of the nanowindow-rim to selectively allow molecules to pass, in an energy-efficiently and fast way (Nature Communications, “Air separation with graphene mediated by nanowindow-rim concerted motion”). This brings up new possibilities to create an advanced molecular separation membrane technology.</i></div><div><i><br /></i></div><div><i>The mechanism of separation by nanowindows is that the atomic vibration of the nanowindow-rim changes the effective nanowidow size. When the rim of one side is deviated and the other is deviated to the opposite direction, the effective nanowindow size becomes larger than when the rim does not move. This effect is very predominant for molecules of oxygen, nitrogen, and argon, inducing an efficient separation of oxygen from air.</i></div><div><a href="https://www.rdworldonline.com/nanowindows-poke-holes-in-graphene/">https://www.rdworldonline.com/nanowindows-poke-holes-in-graphene/</a></div></div><div><br /></div><h4 style="text-align: left;">Transportation of Cargo from Earth to Mars. </h4><div> As for the prospect of sending the hydrogen thus produced backed to Earth, that's actually the easy part. <a href="https://en.wikipedia.org/wiki/Delta-v_budget#Delta-vs_between_Earth,_Moon_and_Mars" target="_blank">The delta-v to reach Earth from the surface of Mars is 6.4 km/s</a>, if you use aerobraking on arrival at Earth. This can easily be supplied by a reusable single-stage-to-orbit from the surface of Mars. And if the CO and O2 can be obtained in an airbreathing manner for propulsion then it can be done even more simply, as discussed in the blog post, "<a href="https://exoscientist.blogspot.com/2023/07/low-cost-commercial-mars-sample-return.html" target="_blank">Low cost commercial Mars Sample Return</a>". <a href="https://en.wikipedia.org/wiki/Mars_cycler" target="_blank">The propellant could also be transported by a Mars cycler.</a></div><div><br /></div><div> Alternatively, this is low enough that a <a href="https://en.wikipedia.org/wiki/Space_elevator" target="_blank">space elevator</a> can do it using currently available materials. Still another possibility is by using a <a href="https://en.wikipedia.org/wiki/Railgun" target="_blank">railgun</a>, i.e., electromagnetic accelerator.</div><div><br /></div><div> </div><div> Robert Clark</div><div><br /></div><div><br /></div><div><br /></div><div> </div>Robert Clarkhttp://www.blogger.com/profile/16114043697010364282noreply@blogger.com0tag:blogger.com,1999:blog-7598615455712402973.post-14024805323959124082023-07-13T17:36:00.005-04:002023-07-16T14:40:29.144-04:00Low cost commercial Mars Sample Return.<p style="text-align: center;"><i><span style="font-family: verdana;"> Copyright 2023 Robert Clark</span></i></p><p><i><span style="font-family: verdana;"><br /></span></i></p><h3 style="text-align: left;"><b><span style="font-family: verdana;">Introduction.</span></b></h3><p><span style="font-family: verdana;"> Mars Sample Return is again being discussed by NASA, as it was 10 years ago. And as was the case then the chief stumbling block is the $10 billion price tag. However, if done as a fully commercial space mission, i.e., no governmental funding required, it could be done for a fraction of the amount NASA is estimating, probably for a few hundred million dollars, including the launch cost on the Falcon Heavy. </span></p><p><span style="font-family: verdana;">SpaceX has shown that development costs for rockets can be done at 1/10th the cost of usual government financed rockets by following the commercial space approach. The same was proven for spacecraft in the form of capsules when SpaceX developed the Dragon at 1/10th the usual cost.</span></p><p><span style="font-family: verdana;"> And Planet Labs was able to produce small, highly functional imaging satellites at a <a href="https://www.bloomberg.com/news/features/2017-06-29/the-tiny-satellites-ushering-in-the-new-space-revolution" target="_blank">fraction of the cost of usual imaging satellites.</a></span></p><p><span style="font-family: verdana;"> This plus using already existing in-space stages rather than developing entire new ones can greatly reduce the development cost of such a mission. </span></p><p><span style="font-family: verdana;"> Here, I will propose a solution using a fully aerocapture approach to landing, meaning braking fully aerodynamically, at Mars to minimize the propulsive burns and therefore propellant that is needed on arrival at Mars. Below we'll discuss some possibilities for this hypersonic slowing. First, the delta-v requirements for such a mission.</span></p><h3 style="text-align: left;"><b><span style="font-family: verdana;">Delta-V to and From Mars.</span></b></h3><p><span style="font-family: verdana;">Here is a map of delta-v's for some locations in Earth-Moon-Mars space:</span></p><h4 style="background-color: white; line-height: 1.6; margin: 0.3em 0px 0px; overflow: hidden; padding-bottom: 0px; padding-top: 0.5em; text-align: left;"><span class="mw-headline" id="Delta-vs_between_Earth,_Moon_and_Mars" style="font-weight: normal;"><span style="font-family: verdana;">Delta-v's between Earth, Moon and Mars.</span></span></h4><p></p><div class="separator" style="clear: both; text-align: center;"><a href="http://upload.wikimedia.org/wikipedia/commons/thumb/c/c9/Deltavs.svg/500px-Deltavs.svg.png" style="margin-left: 1em; margin-right: 1em;"><span style="font-family: verdana;"><img border="0" data-original-height="707" data-original-width="500" height="707" src="http://upload.wikimedia.org/wikipedia/commons/thumb/c/c9/Deltavs.svg/500px-Deltavs.svg.png" width="500" /></span></a></div><div style="text-align: center;"><a href="http://en.wikipedia.org/wiki/Delta-v_budget#Delta-vs_between_Earth.2C_Moon_and_Mars"><span style="font-family: verdana;">http://en.wikipedia.org/wiki/Delta-v_budget#Delta-vs_between_Earth.2C_Moon_and_Mars</span></a></div><div style="text-align: center;"><span style="font-family: verdana;"><br /></span></div><div style="text-align: left;"><span style="font-family: verdana;"><br /></span></div><span style="background-color: #fbfaf5;"><div style="color: #333333;"><span style="font-family: verdana;">LEO to GTO: 2.5 km/s</span></div><div style="color: #333333;"><span style="font-family: verdana;">GTO to Earth C3: .7 km/s</span></div><div style="color: #333333;"><span style="font-family: verdana;">Earth C3 to Mars transfer: .6 km/s</span></div><div style="color: #333333;"><span style="font-family: verdana;"><br /></span></div><div style="color: #333333;"><span style="font-family: verdana;">Now notice for the delta-v's after this leading into Mars they all have red arrows indicating this part of the trip can be done by aerocapture/aerobraking. So this portion of the flight leaving Earth orbit headed towards Mars, and landing on the surface is only 3.8 km/s, assuming all the slowing on reaching Mars is done aerodynamically.</span></div><div style="color: #333333;"><span style="font-family: verdana;"><br /></span></div><div style="color: #333333;"><span style="font-family: verdana;"> After that, for the return trip:</span></div><div style="color: #333333;"><span style="font-family: verdana;"><br /></span></div><div style="color: #333333;"><span style="font-family: verdana;">Mars(surface) to low Mars orbit: 4.1 km/s</span></div><div style="color: #333333;"><span style="font-family: verdana;">Low Mars orbit to Phobos transfer: .9 km/s</span></div><div style="color: #333333;"><span style="font-family: verdana;">Phobos transfer to Deimos transfer: .3 km/s</span></div><div style="color: #333333;"><span style="font-family: verdana;">Deimos transfer to Mars C3: .2 km/s</span></div><div style="color: #333333;"><span style="font-family: verdana;">Mars C3 to Mars transfer: .9 km/s</span></div><div style="color: #333333;"><span style="font-family: verdana;"><br /></span></div><div style="color: #333333;"><span style="font-family: verdana;">Now the delta-v's after this leading from the graph into Earth all have red arrows indicating this part of the trip can be done by aerobraking. So the return part of the trip can amount to only 6.4 km/s, for a total of 10.2 km/s for the round trip, if the final part of the trip of returning to the Earth's surface is done fully by aerodynamic braking, i.e., not using propulsive burns.</span></div><div style="color: #333333;"><span style="font-family: verdana;"><br /></span></div><div style="color: #333333;"><span style="font-family: verdana;"> As for the heat shield for these Mars return velocities notice that the SpaceX Dragon's PICA-X heat shield was designed to withstand such velocities. It reportedly weighs only half of Apollo era heat shields which would put it at about 8% of the landed mass.</span></div><div style="color: #333333;"><span style="font-family: verdana;"><br /></span></div><div><div style="color: #333333;"><span style="font-family: verdana;">However, for the sample being returned to Earth from Mars there is concern that there may be unknown microorganisms. So current plans include the sample being returned only to Earth orbit or to lunar orbit. Thereafter, the sample would be studied in some orbiting facility only or be placed in a special canister with several redundant layers of security for return to Earth designed not to be breached even if it crashes on return to Earth's surface.</span></div><div style="color: #333333;"><span style="font-family: verdana;"><br /></span></div><div style="color: #333333;"><span style="font-family: verdana;"> In such case, we have two additional steps in the delta-v chart:</span></div><div style="color: #333333;"><span style="font-family: verdana;"><br /></span></div><div style="color: #333333;"><span style="font-family: verdana;">Mars transfer to Earth C3: .6 km/s</span></div><div style="color: #333333;"><span style="font-family: verdana;">Earth C3 to GTO: .7 km/s</span></div><div style="color: #333333;"><span style="font-family: verdana;"><br /></span></div><div style="color: #333333;"><span style="font-family: verdana;"> For a total of 6.4 km/s +.6 km/s + .7 km/s = 7.7 km/s.</span></div><div style="color: #333333;"><span style="font-family: verdana;"><br /></span></div><div style="color: #333333;"><span style="font-family: verdana;"> This would be for when the sample is returned to geosynchronous transfer orbit(GTO). This is an intermediate orbit for getting to actual geosynchronous orbit. It is a highly elliptical orbit with closest point in low Earth orbit and farthest point at geosynchronous altitude of 35,700 km.</span></div><div style="color: #333333;"><span style="font-family: verdana;"><br /></span></div><div style="color: #333333;"><span style="font-family: verdana;"> The other possibility would be to send instead to lunar orbit. Then the additional delta-v steps would be:</span></div><div style="color: #333333;"><span style="font-family: verdana;"><br /></span></div><div style="color: #333333;"><span style="font-family: verdana;">Mars transfer to Earth C3: .6 km/s</span></div><div style="color: #333333;"><span style="font-family: verdana;">Earth C3 to lunar orbit: .7 km/s</span></div><div style="color: #333333;"><span style="font-family: verdana;"><br /></span></div><div style="color: #333333;"><span style="font-family: verdana;"> The total delta-v for the return this time to lunar orbit would also be 7.7 km/s. </span></div><div style="color: #333333;"><span style="font-family: verdana;"><br /></span></div><div style="color: #333333;"><span style="font-family: verdana;">Now for the rocket stages for getting to Mars and returning a sample back. First, we'll use the Falcon Heavy for lofting the in-space stages first into space. Falcon Heavy has a payload capacity of 63.8 tons to LEO, <a href="https://en.wikipedia.org/wiki/Falcon_Heavy#Capabilities" target="_blank">but only 16.8 tons to Mars transfer orbit(MTO)</a>. This is a trajectory that sends a spacecraft to encounter Mars in its orbit about the Sun, but makes no attempt to actually enter orbit around Mars. This is the scenario we are considering where, once reaching Mars, the entire braking and landing on the surface is done aerodynamically.</span></div><div style="color: #333333;"><span style="font-family: verdana;"><br /></span></div><div style="color: #333333;"><span style="font-family: verdana;">So we have 16.8 tons to work with for in-space stages with capacity to lift off from Mars, fire a burn to direct the return craft back to Earth, and finally make the burn to put the craft in GTO orbit or lunar orbit.</span></div><div style="color: #333333;"><span style="font-family: verdana;"><br /></span></div><div style="color: #333333;"><span style="font-family: verdana;"> We'll select existing stages using storable propellant for the in-space stages for this mission that may take up to 3 years round trip duration.</span></div><div style="color: #333333;"><span style="font-family: verdana;"><br /></span></div><div style="color: #333333;"><span style="font-family: verdana;">For the first in-space stage we'll use the <a href="https://www.esa.int/Enabling_Support/Space_Transportation/Launch_vehicles/Storable_Propellant_Stage_EPS" target="_blank">Ariane 5's EPS storable propellant stage</a>. </span></div><div style="color: #333333; font-size: 13px;"><span style="font-family: verdana;"><br /></span></div><div class="separator" style="clear: both; color: #333333; font-size: 13px; text-align: center;"><a href="https://galileognss.eu/wp-content/uploads/2017/11/Flight-VA240-Installation-of-Ariane-5%E2%80%99s-EPS-storable-propellant-upper-stage.jpg" style="margin-left: 1em; margin-right: 1em;"><span style="font-family: verdana;"><img border="0" data-original-height="565" data-original-width="800" height="452" src="https://galileognss.eu/wp-content/uploads/2017/11/Flight-VA240-Installation-of-Ariane-5%E2%80%99s-EPS-storable-propellant-upper-stage.jpg" width="640" /></span></a></div><span style="color: #333333; font-family: verdana;"><br /></span><div style="color: #333333; font-size: 13px;"><span style="font-family: verdana;"><br /></span></div><div style="color: #333333;"><span style="font-family: verdana;"> This has about ~9.8 ton propellant load and ~1.3 ton dry mass. It uses the Aestus storable propellant, pressure-fed engine at about 324 s vacuum Isp at an 84 to 1 expansion ratio. However, <a href="http://www.astronautix.com/r/rs-72.html" target="_blank">an upgraded version turbopump-fed got 340 s vacuum Isp at 300 to 1 expansion ratio</a>. Astronautix.com lists its <a href="http://www.astronautix.com/a/ariane5-2.html" target="_blank">price as $6 million.</a></span></div><div style="color: #333333;"><span style="font-family: verdana;"> </span></div><div style="color: #333333;"><span style="font-family: verdana;"> After that, we'll use two copies of the <a href="https://en.wikipedia.org/wiki/Integrated_Apogee_Boost_Stage" target="_blank">Integrated Apogee Boost Stage(IABS)</a>, at about 1.3 tons storable propellant load and about .275 ton dry mass.</span></div><div style="color: #333333; font-size: 13px;"><span style="font-family: verdana;"><br /></span></div><div class="separator" style="clear: both; color: #333333; font-size: 13px; text-align: center;"><a href="http://www.spaceflightnow.com/atlas/ac140/images/dscsiabs.jpg" style="margin-left: 1em; margin-right: 1em;"><span style="font-family: verdana;"><img border="0" data-original-height="249" data-original-width="220" height="400" src="http://www.spaceflightnow.com/atlas/ac140/images/dscsiabs.jpg" width="353" /></span></a></div><span style="color: #333333; font-family: verdana;"><br /></span><div style="color: #333333;"><span style="font-family: verdana;"><br /></span></div><div style="color: #333333;"><span style="font-family: verdana;"> This stage had an vacuum Isp of 312 s. However, for an in-space only stage vacuum Isp is primarily a function of expansion ratio so we'll assume we can also give it a vacuum isp of 340 s with sufficiently large nozzle of ca. 300 to 1 area expansion ratio. Astronautix.com lists its <a href="http://www.astronautix.com/i/iabs.html" target="_blank">price as $15 million</a>.</span></div><div style="color: #333333;"><span style="font-family: verdana;"><br /></span></div><div style="color: #333333;"><span style="font-family: verdana;"> Then with these three stages we can get about <b>.75</b> tons, 750 kg, payload to reach the 7.7 km/s delta-v needed for the round trip to Mars and back:</span></div><div style="color: #333333;"><span style="font-family: verdana;"><br /></span></div><div style="color: #333333;"><span style="font-family: verdana;">3400(Ln(1 + 1.3/(.275 +<b> .75</b>)) + Ln(1 + 1.3/(.275 + 1.575 + <b>.75</b>)) + Ln(1 + 9.8/(1.3 + 1.575 + 1.575 + <b>.75</b>))) = 7,760 m/s, 7.76 km/s.</span></div><div style="color: #333333;"><span style="font-family: verdana;"><br /></span></div><div style="color: #333333;"><span style="font-family: verdana;"> The total mass of all the stages and the payload is 15 tons, within the 16.8 ton limit of the Falcon Heavy to put into Mars Transfer Orbit(MTO).</span></div><div style="color: #333333;"><span style="font-family: verdana;"> </span></div><h3 style="color: #333333; text-align: left;"><b><span style="font-family: verdana; font-size: small;">Full Aerocapture/Aerobraking for Landing at Mars.</span></b></h3><div style="color: #333333;"><span style="font-family: verdana;"> The question of using aerocapture at Mars is a major question at NASA now for large payloads in the 15 tons to 25 tons range for landing of human habitats for manned missions to Mars. The earlier methods for landing using to a large extent propulsive landing would require a prohibitive amount of propellant (for the usual propulsion methods. However see below.) </span></div><div style="color: #333333;"><span style="font-family: verdana;"><br /></span></div><div style="color: #333333;"><span style="font-family: verdana;"> On the other land using just parachutes or spherical section reentry capsules because of the thin atmosphere would also be insufficient for such large payloads. See discussion here:</span></div><div style="color: #333333;"><span style="font-family: verdana;"><br /></span></div><div style="color: #333333;"><div><span style="font-family: verdana;">The Mars Landing Approach: Getting Large Payloads to the Surface of the Red Planet.</span></div><div><span style="font-family: verdana;">JULY 17, 2007 BY NANCY ATKINSON</span></div><div><i><span style="font-family: verdana;">Some proponents of human missions to Mars say we have the technology today to send people to the Red Planet. But do we? Rob Manning of the Jet Propulsion Laboratory discusses the intricacies of entry, descent and landing and what needs to be done to make humans on Mars a reality.</span></i></div><div><i><span style="font-family: verdana;"><br /></span></i></div><div><i><span style="font-family: verdana;">There’s no comfort in the statistics for missions to Mars. To date over 60% of the missions have failed. The scientists and engineers of these undertakings use phrases like “Six Minutes of Terror,” and “The Great Galactic Ghoul” to illustrate their experiences, evidence of the anxiety that’s evoked by sending a robotic spacecraft to Mars — even among those who have devoted their careers to the task. But mention sending a human mission to land on the Red Planet, with payloads several factors larger than an unmanned spacecraft and the trepidation among that same group grows even larger. Why?</span></i></div><div><i><span style="font-family: verdana;"><br /></span></i></div><div><i><span style="font-family: verdana;">Nobody knows how to do it.</span></i></div><div><a href="https://www.universetoday.com/7024/the-mars-landing-approach-getting-large-payloads-to-the-surface-of-the-red-planet/"><span style="font-family: verdana;">https://www.universetoday.com/7024/the-mars-landing-approach-getting-large-payloads-to-the-surface-of-the-red-planet/</span></a></div></div><div style="color: #333333;"><span style="font-family: verdana;"><br /></span></div><div style="color: #333333;"><span style="font-family: verdana;"><br /></span></div><div style="color: #333333;"><span style="font-family: verdana;"> One possibility for how to do it is hypersonic waveriders:</span></div><div style="color: #333333;"><span style="font-family: verdana;"><br /></span></div><div><div style="color: #333333;"><span style="font-family: verdana;">Hypersonic waveriders for planetary atmospheres.</span></div><div style="color: #333333;"><span style="font-family: verdana;">December 1989 Journal of Spacecraft and Rockets -1(4)</span></div><div style="color: #333333;"><span style="font-family: verdana;">DOI: 10.2514/3.26259</span></div><div style="color: #333333;"><span style="font-family: verdana;">Anderson, John D., Jr MARK J. LEWIS, Ajay Kothari, Stephen Corda</span></div><div style="color: #333333;"><span style="font-family: verdana;">International Hypersonic Waverider Symposium, 1st, University of Maryland, College Park, MD, Oct. 17-19, 1990, Proceedings</span></div><div style="color: #333333;"><span style="font-family: verdana;">Article</span></div><div style="color: #333333;"><span style="font-family: verdana;">January 1990</span></div><div style="color: #333333;"><i><span style="font-family: verdana;">The concept of a hypersonic waverider for application in foreign planetary atmospheres is explored, particularly in regard to aero-assist for space vehicle trajectory modification. The overall concept of hypersonic waveriders is discussed in tutorial fashion. A review of past work is given, and the role of a new family of waveriders - the viscous optimized waveriders generated at the University of Maryland - is highlighted. The mechanics of trajectory modification by aerodynamic vehicles with high lift-to-drag ratios in planetary atmospheres is explored. Actual hypersonic waverider designs for Mars and Venus atmospheres are presented. These are the first waveriders ever presented for foreign planetary atmospheres. Moreover, they exhibit very high lift-to-drag ratios, as high as 15 in the Venus atmosphere. These results graphically demonstrate that a hypersonic waverider is a viable candidate for aero-assist maneuvers in foreign planetary atmospheres.</span></i></div><div style="color: #333333;"><a href="https://www.researchgate.net/publication/234442827_Hypersonic_waveriders_for_planetary_atmospheres" style="font-size: 13px;"><span style="font-family: verdana;">https://www.researchgate.net/publication/234442827_Hypersonic_waveriders_for_planetary_atmospheres</span></a></div><div style="color: #333333;"><span style="font-size: 13px;"><i><span style="font-family: verdana;"><br /></span></i></span></div><div style="color: #333333;"><span style="font-size: 13px;"><span style="font-family: verdana;"><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhhjzDDNCyNTTiPaNwkP0Q6vCoo9V-584Ccp68kE_IDFIamCsF7J_ZS8LC9axTHAbsqryWbMFIqT9Vfeh2DULEfFyJHgPxa6qanv_pJZbsDZRnAKg0SLdEDYUhlnvaMeZ_KkpBIhHijUwllj_RVv2-v7GGIJZ3RZSWzIMDwxnqRTcVOYuBiGpdu2ns_Kh0/s810/Hyperson%20L-D%20ratio.JPG" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="479" data-original-width="810" height="378" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhhjzDDNCyNTTiPaNwkP0Q6vCoo9V-584Ccp68kE_IDFIamCsF7J_ZS8LC9axTHAbsqryWbMFIqT9Vfeh2DULEfFyJHgPxa6qanv_pJZbsDZRnAKg0SLdEDYUhlnvaMeZ_KkpBIhHijUwllj_RVv2-v7GGIJZ3RZSWzIMDwxnqRTcVOYuBiGpdu2ns_Kh0/w640-h378/Hyperson%20L-D%20ratio.JPG" width="640" /></a></div><br /><i><br /></i></span></span></div><div style="color: #333333;"><span style="font-family: verdana;"> As shown if Figure 4 from the article, the hypersonic L/D ratio with waveriders can approach 10. </span></div><div style="color: #333333;"><span style="font-family: inherit;"><br /></span></div><div style="color: #333333;"><span style="font-family: verdana;">Further examination of hypersonic waveriders for reentry given here:</span></div><div style="color: #333333;"><span style="font-family: inherit;"><br /></span></div><p style="background-color: white; clear: both; color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px; text-align: left;"><span style="font-family: inherit; font-size: medium;"><a href="https://www.researchgate.net/publication/319285796_An_overview_of_research_on_waverider_design_methodology" style="color: #2288bb; text-decoration-line: none;" target="_blank">An overview of research on waverider design methodology</a></span><br /><span style="font-family: inherit; font-size: medium;"></span></p><li class="nova-legacy-e-list__item" style="background-color: white; color: var(--nova-color-grey-600); display: inline; font-family: var(--nova-font-family-sans-serif); font-size: 13.2px; line-height: 1.3; margin: 0px 0px 0.5em; padding: 0px; text-transform: inherit;"><span style="font-family: inherit; font-size: medium;">August 2017</span></li><li class="nova-legacy-e-list__item" style="background-color: white; color: var(--nova-color-grey-600); display: inline; font-family: var(--nova-font-family-sans-serif); font-size: 13.2px; line-height: 1.3; margin: 0px 0px 0.25em; padding: 0px; text-transform: inherit;"><span style="font-family: inherit; font-size: medium;"><a class="nova-legacy-e-link nova-legacy-e-link--color-inherit nova-legacy-e-link--theme-decorated" href="https://www.researchgate.net/publication/319285796_An_overview_of_research_on_waverider_design_methodology/journal/Acta-Astronautica-0094-5765" style="background-image: none; border: 0px; color: #2288bb; cursor: pointer; display: inline; margin: 0px; outline: none; padding: 0px; text-align: inherit; text-decoration-line: none;">Acta Astronautica</a> 140</span></li><ul class="nova-legacy-e-list nova-legacy-e-list--size-m nova-legacy-e-list--type-inline nova-legacy-e-list--spacing-none research-detail-meta__item-list" style="background-color: white; color: #222222; font-family: var(--nova-font-family-sans-serif); font-size: 13.2px; line-height: 1; list-style: none; margin: 0px; padding: 0px;"><span style="font-family: inherit; font-size: medium;"><li class="nova-legacy-e-list__item" style="display: inline; line-height: 1.3; margin: 0px 0px 0.5em; padding: 0px;">DOI: </li><li class="nova-legacy-e-list__item" style="display: inline; line-height: 1.3; margin: 0px 0px 0.25em; padding: 0px;"><a class="nova-legacy-e-link nova-legacy-e-link--color-inherit nova-legacy-e-link--theme-decorated" href="http://dx.doi.org/10.1016/j.actaastro.2017.08.027" rel="noopener" style="background-image: none; border: 0px; color: #2288bb; cursor: pointer; display: inline; margin: 0px; outline: none; padding: 0px; text-align: inherit; text-decoration-line: none;" target="_blank">10.1016/j.actaastro.2017.08.027</a></li></span></ul><ul class="nova-legacy-e-list nova-legacy-e-list--size-m nova-legacy-e-list--type-inline nova-legacy-e-list--spacing-none research-detail-meta__item-list" style="background-color: white; color: #222222; font-family: var(--nova-font-family-sans-serif); font-size: 13.2px; line-height: 1; list-style: none; margin: 0px; padding: 0px;"><span style="font-family: inherit; font-size: medium;"><li class="nova-legacy-e-list__item" style="display: inline; line-height: 1.3; margin: 0px 0px 0.5em; padding: 0px;">Project: </li><li class="nova-legacy-e-list__item" style="display: inline; line-height: 1.3; margin: 0px 0px 0.25em; padding: 0px;"><a class="nova-legacy-e-link nova-legacy-e-link--color-inherit nova-legacy-e-link--theme-decorated" href="https://www.researchgate.net/publication/319285796_An_overview_of_research_on_waverider_design_methodology/project/Aerodynamic-design-theory-and-methodology-of-hypersonic-waverider-vehicle" style="background-image: none; border: 0px; color: #2288bb; cursor: pointer; display: inline; margin: 0px; outline: none; padding: 0px; text-align: inherit; text-decoration-line: none;">Aerodynamic design theory and methodology of hypersonic waverider vehicle</a></li></span></ul><ul class="nova-legacy-e-list nova-legacy-e-list--size-m nova-legacy-e-list--type-inline nova-legacy-e-list--spacing-xl" style="background-color: white; caret-color: rgb(17, 17, 17); color: #111111; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px; line-height: 1; list-style: none; margin: 0px 0px 30px; padding: 0px; text-size-adjust: 100%;"><span style="font-family: inherit; font-size: medium;"><li class="nova-legacy-e-list__item" style="display: inline; line-height: 1.3; margin: 0px 0px 0.5em; padding: 0px;"><span role="status"><a class="nova-legacy-e-link nova-legacy-e-link--color-inherit nova-legacy-e-link--theme-bare research-detail-author" href="https://www.researchgate.net/publication/319285796_An_overview_of_research_on_waverider_design_methodology/profile/Feng-Ding-2?_sg%5B0%5D=jZA2Kv89tYvEVQ0IW2OK5ABQM7GHK9OOJEPoAnaVzSCFtPq9wEgOtY5xf7WsMCfZy1eVfpU.IkAwHEtm7vv4fTGBIgiCiWYjUZS06MpLCZL1d3ZIFtd-Lii_KJbpjCEV-QDD07PnTtAqcG-nnea5fO150ErO4Q&_sg%5B1%5D=wGPGerISb_qXOeFPL3EvFSPxNwhvvGRTVV0H2gaVgvx88JbrLIjjv3SOHsw1qAmx9vnUwf8.gCM0h9KoyVe_ERr-6587EBMG5taQFPGqhfOZPhG0_HDsx2qzjc6JWUiVbUk0X0yqpZ0d1MOsKj5vqs1edZARrA" style="background-image: none; border: 0px; color: #2288bb; cursor: pointer; display: inline; margin: 0px; outline: none; padding: 0px; text-align: inherit; text-decoration-line: none; white-space: nowrap;" tabindex="0"><img alt="Feng Ding" class="research-detail-author__image" src="https://i1.rgstatic.net/ii/profile.image/622332292894720-1525386989107_Q64/Feng-Ding-2.jpg" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; border-radius: 624.938rem; border: 0px; box-shadow: rgba(0, 0, 0, 0.1) 1px 1px 5px; height: 16px; margin-right: 5px; padding: 5px; position: relative; vertical-align: top;" />Feng Ding</a> </span></li><li class="nova-legacy-e-list__item" style="display: inline; line-height: 1.3; margin: 0px 0px 0.5em; padding: 0px;"><span role="status"><a class="nova-legacy-e-link nova-legacy-e-link--color-inherit nova-legacy-e-link--theme-bare research-detail-author" href="https://www.researchgate.net/publication/319285796_An_overview_of_research_on_waverider_design_methodology/scientific-contributions/Jun-Liu-2094350419?_sg%5B0%5D=jZA2Kv89tYvEVQ0IW2OK5ABQM7GHK9OOJEPoAnaVzSCFtPq9wEgOtY5xf7WsMCfZy1eVfpU.IkAwHEtm7vv4fTGBIgiCiWYjUZS06MpLCZL1d3ZIFtd-Lii_KJbpjCEV-QDD07PnTtAqcG-nnea5fO150ErO4Q&_sg%5B1%5D=wGPGerISb_qXOeFPL3EvFSPxNwhvvGRTVV0H2gaVgvx88JbrLIjjv3SOHsw1qAmx9vnUwf8.gCM0h9KoyVe_ERr-6587EBMG5taQFPGqhfOZPhG0_HDsx2qzjc6JWUiVbUk0X0yqpZ0d1MOsKj5vqs1edZARrA" style="background-image: none; border: 0px; color: #2288bb; cursor: pointer; display: inline; margin: 0px; outline: none; padding: 0px; text-align: inherit; text-decoration-line: none; white-space: nowrap;" tabindex="0">Jun Liu</a> </span></li><li class="nova-legacy-e-list__item" style="display: inline; line-height: 1.3; margin: 0px 0px 0.5em; padding: 0px;"><span role="status"><a class="nova-legacy-e-link nova-legacy-e-link--color-inherit nova-legacy-e-link--theme-bare research-detail-author" href="https://www.researchgate.net/publication/319285796_An_overview_of_research_on_waverider_design_methodology/scientific-contributions/Chi-bing-Shen-2060915847?_sg%5B0%5D=jZA2Kv89tYvEVQ0IW2OK5ABQM7GHK9OOJEPoAnaVzSCFtPq9wEgOtY5xf7WsMCfZy1eVfpU.IkAwHEtm7vv4fTGBIgiCiWYjUZS06MpLCZL1d3ZIFtd-Lii_KJbpjCEV-QDD07PnTtAqcG-nnea5fO150ErO4Q&_sg%5B1%5D=wGPGerISb_qXOeFPL3EvFSPxNwhvvGRTVV0H2gaVgvx88JbrLIjjv3SOHsw1qAmx9vnUwf8.gCM0h9KoyVe_ERr-6587EBMG5taQFPGqhfOZPhG0_HDsx2qzjc6JWUiVbUk0X0yqpZ0d1MOsKj5vqs1edZARrA" style="background-image: none; border: 0px; color: #2288bb; cursor: pointer; display: inline; margin: 0px; outline: none; padding: 0px; text-align: inherit; text-decoration-line: none; white-space: nowrap;" tabindex="0">Chi-bing Shen</a> et al. </span></li></span></ul><div style="color: #333333;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjXHz0PdAst0U-jLelkq3Pi8XyPWPh2Nvi9D7ToxZ3Oqxs3HSpYRG0o3oez5XHrndMKDEZEs9qhnBVAkIJYNsDYtXLuo5eCt91F83hOvIPFXcvHwkTFuceT0K3G66D5w5Ry3sBpd9mUYSLtQAGXiowIi85_SJUJw9iKiSOM1KB9buwQNCUJ04IXGNlV/s872/8CCBB404-1846-44E8-AB93-3219926E6016.jpeg" style="background-color: white; color: #2288bb; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px; margin-left: 1em; margin-right: 1em; text-decoration-line: none;"><img border="0" data-original-height="872" data-original-width="640" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjXHz0PdAst0U-jLelkq3Pi8XyPWPh2Nvi9D7ToxZ3Oqxs3HSpYRG0o3oez5XHrndMKDEZEs9qhnBVAkIJYNsDYtXLuo5eCt91F83hOvIPFXcvHwkTFuceT0K3G66D5w5Ry3sBpd9mUYSLtQAGXiowIi85_SJUJw9iKiSOM1KB9buwQNCUJ04IXGNlV/w470-h640/8CCBB404-1846-44E8-AB93-3219926E6016.jpeg" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; border: 1px solid rgb(238, 238, 238); box-shadow: rgba(0, 0, 0, 0.1) 1px 1px 5px; padding: 5px; position: relative;" width="470" /></a><span style="font-family: inherit;"> </span></div><div style="color: #333333;"><span style="font-family: inherit;"><br /></span></div><div style="color: #333333;"><span style="font-family: inherit;"> </span></div><div style="color: #333333;"><span style="font-family: inherit;"> </span><span style="font-family: verdana;">A variation on that idea is clam-shell wings during reentry: </span></div><div style="color: #333333;"><span style="font-family: verdana;"><br /></span></div><div><div style="color: #333333;"><span style="font-family: verdana;">Clamshell wings for hypersonic reentry of rocket stages. UPDATED, May 4, 2023.</span></div><div style="color: #333333;"><a href="http://exoscientist.blogspot.com/2023/02/clamshell-wings-for-hypersonic-reentry.html"><span style="font-family: verdana;">http://exoscientist.blogspot.com/2023/02/clamshell-wings-for-hypersonic-reentry.html</span></a></div><div style="color: #333333;"><span style="font-family: verdana;"><br /></span></div><div style="color: #333333;"><span style="font-family: verdana;"> An advantage of this over usual caret-shaped hypersonic waveriders is that split in two parts and being curved they can they can more than double the underside surface area.</span></div><div style="color: #333333;"><span style="font-family: inherit;"><br /></span></div><div style="color: #333333;"><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiINa4cQaqbaDJogEIdDf63ZLn6LDVK2MwuaQ718C7tgc1C2RErzH-Dp8Z3LgYeknLjwbfsW7wmO3tliY7mINeGtkoiOHn163PQGCMhoBd9hWQKIIbqUBzebdM0lD7IQoYD0u6xk2ESjVaD8juxGZPzUlIfSMoBFQhvW_BwV2hz0bUIgYh00IH6x0LS/s400/_Clark-Fairing_Falcon9_02.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="225" data-original-width="400" height="360" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiINa4cQaqbaDJogEIdDf63ZLn6LDVK2MwuaQ718C7tgc1C2RErzH-Dp8Z3LgYeknLjwbfsW7wmO3tliY7mINeGtkoiOHn163PQGCMhoBd9hWQKIIbqUBzebdM0lD7IQoYD0u6xk2ESjVaD8juxGZPzUlIfSMoBFQhvW_BwV2hz0bUIgYh00IH6x0LS/w640-h360/_Clark-Fairing_Falcon9_02.png" width="640" /></a></div><br /><span style="font-family: inherit;"><br /></span></div><div><div class="separator" style="clear: both; color: #333333; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEimVThfWghJ9TNr30i5lxudzpapuhXw4GGxGAMcSKHFt677a8vZWqmZuA01h4ubnlZ1sFB68c78qEm5RqEfxPJoIr8Zs_QWCWAgwq4v0wXvCZzOMH1UPLsSrpPPxZo3NoGI2StLeHbiITpnk_-yfpbrfNtytzDkEifOn7VD1OAzriznDN-6Jng6R3DR/s400/_Clark-Fairing_Falcon9_03.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="225" data-original-width="400" height="360" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEimVThfWghJ9TNr30i5lxudzpapuhXw4GGxGAMcSKHFt677a8vZWqmZuA01h4ubnlZ1sFB68c78qEm5RqEfxPJoIr8Zs_QWCWAgwq4v0wXvCZzOMH1UPLsSrpPPxZo3NoGI2StLeHbiITpnk_-yfpbrfNtytzDkEifOn7VD1OAzriznDN-6Jng6R3DR/w640-h360/_Clark-Fairing_Falcon9_03.png" width="640" /></a></div><br /><ul class="nova-legacy-e-list nova-legacy-e-list--size-m nova-legacy-e-list--type-inline nova-legacy-e-list--spacing-xl" style="background-color: white; caret-color: rgb(17, 17, 17); color: #111111; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; line-height: 1; list-style: none; margin: 0px 0px 30px; padding: 0px; text-size-adjust: 100%;"><div class="separator" style="clear: both; text-align: center;"><div class="separator" style="clear: both;"><span style="font-family: inherit; font-size: x-small;"><i>Falcon 9 opened up fairing as clam-shell wings.</i></span></div></div><div class="separator" style="clear: both; text-align: center;"><div class="separator" style="clear: both;"><i><span style="font-size: x-small;">Renders Credit <a href="https://casparstanley.com/" style="color: #2288bb; text-decoration-line: none;" target="_blank">Caspar Stanley</a> </span></i></div></div></ul><div style="text-align: left;"><span style="color: #111111;"><span style="caret-color: rgb(17, 17, 17);"><i style="font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif;"> </i><span style="font-family: inherit;">Research has shown that further lift can be provided by hypersonic bi-foils:</span></span></span></div><div style="text-align: left;"><span style="color: #111111;"><span style="caret-color: rgb(17, 17, 17);"><span style="font-family: inherit;"><br /></span></span></span></div><div style="text-align: left;"><span style="color: #111111;"><span style="caret-color: rgb(17, 17, 17);"><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg3SdZsYTVQKp8rvF9WPuxbVDHZjDA1qeDgqdy3jU8qY237SlRLmL1Tu9jqHwkSjx-JnxesmPfaTZ2VEf9pJxodY_sBIkP4vox54iVS0iyY_h7hYdZU6eT_IXJ4dS9yYdDqgzeYHC6sRH6oHgrUlA3pBiVUq5BXZk_g6F7j4xAbr1TfDA5y5DvE_2iC/s640/AB1337A5-76AE-4A94-B4A5-B8F71A6485B2.webp" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="390" data-original-width="640" height="390" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg3SdZsYTVQKp8rvF9WPuxbVDHZjDA1qeDgqdy3jU8qY237SlRLmL1Tu9jqHwkSjx-JnxesmPfaTZ2VEf9pJxodY_sBIkP4vox54iVS0iyY_h7hYdZU6eT_IXJ4dS9yYdDqgzeYHC6sRH6oHgrUlA3pBiVUq5BXZk_g6F7j4xAbr1TfDA5y5DvE_2iC/w640-h390/AB1337A5-76AE-4A94-B4A5-B8F71A6485B2.webp" width="640" /></a></div><br /></span></span><span face="Arial, Tahoma, Helvetica, FreeSans, sans-serif" style="background-color: white; caret-color: rgb(51, 51, 51); color: #333333;"><a href="https://www.popsci.com/china-hypersonic-double-wing-aircraft-i-plane/" style="color: #33aaff;" target="_blank"><span style="font-size: x-small;"><span style="-webkit-tap-highlight-color: rgba(0, 0, 0, 0); caret-color: rgb(33, 37, 41); color: #212529; text-size-adjust: 100%;"><i>The hypersonic I Plane has a unique biplane configuration to increase its payload and reduce drag. </i></span><span class="SingleImage-credit" style="--tw-ring-color: rgba(147, 197, 253, 0.5); --tw-ring-inset: var(--tw-empty, ); --tw-ring-offset-color: #fff; --tw-ring-offset-shadow: 0 0 #0000; --tw-ring-offset-width: 0px; --tw-ring-shadow: 0 0 #0000; --tw-shadow: 0 0 #0000; -webkit-tap-highlight-color: rgba(0, 0, 0, 0); box-sizing: border-box; caret-color: rgb(33, 37, 41); color: #212529; margin: 0px; padding: 0px; text-size-adjust: 100%;"><i>China Science Press</i></span></span></a></span></div><div style="text-align: left;"><br /></div><div style="text-align: left;"><i> </i></div><div style="text-align: left;"><i> A key advantage of such high hypersonic L/D ratios, is that using lift we can curve the craft around the planet giving it further time to slow down in contrast to traveling in a straight-line and exiting the planets atmosphere with insufficient braking to fall below the planets escape velocity.</i></div></div></div></div><div style="color: #333333; font-size: 13px;"><span style="font-family: inherit;"><br /></span></div><h3 style="color: #333333; text-align: left;"><span style="font-family: verdana; font-size: small;">Possible Light Weight Propulsive Methods for Landing.</span></h3><div><span style="font-family: verdana; font-size: small;"> Because of the high delta-v requirements for such a mission it was thought the propellant requirements for a propulsive landing would be prohibitive. However, at least two different methods might make it possible, both by getting all or part of the propellant from the Martian atmosphere.</span></div><div><span style="font-family: verdana; font-size: small;"><br /></span></div><div><span style="font-family: verdana; font-size: small;">1.)On Earth, oxygen is the common oxidizer for burning. However some metals in such as magnesium and aluminum burn quite well in a carbon dioxide atmosphere, especially as fine powdered particles:</span></div><div><span style="font-family: verdana; font-size: small;"><br /></span></div><div><span style="font-family: verdana; font-size: small;"><div>The General Chemistry Demo Lab</div><div>Reaction Of Magnesium Metal With Carbon Dioxide.</div><div><a href="http://www.ilpi.com/genchem/demo/co2mg/index.html">http://www.ilpi.com/genchem/demo/co2mg/index.html</a></div><div><br /></div><div><div>Original Articles</div><div>Combustion of Aluminum Particles in Carbon Dioxide</div><div>SERGIO ROSSI,EDWARD L DREIZIN &CHUNG K. LAW</div><div>Pages 209-237 | Received 05 May 2000, Accepted 30 Nov 2000, Published online: 27 Apr 2007</div><div><a href="https://www.tandfonline.com/doi/abs/10.1080/00102200108952170">https://www.tandfonline.com/doi/abs/10.1080/00102200108952170</a></div></div><div><br /></div><div>2.)Both oxygen and carbon monoxide from the Martian atmosphere. </div><div>That Mars atmosphere is overwhelmingly carbon dioxide is well known. However, it is notable that it contains small amounts of oxygen and carbon monoxide. </div><div><br /></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhnNnTJFTRzVXLmQRCGrQ0--tMh2UZMwQYd7ZzTLH4DrbMti7rJ3GWXcEkAV5J-h3kir3KUfy7QSvxUP0fIHgAhNBShA3j6QP6O0ZcJU0EsMgIr_J8xnDlF2Cz7VU1OtAoZ8UJmDF4CVBgEFNDxmdvdmSCFLOS07Bw06xf0uj4o0L1i6hHG8llypuewwbs/s535/Mars%20atmosphere.JPG" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="535" data-original-width="265" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhnNnTJFTRzVXLmQRCGrQ0--tMh2UZMwQYd7ZzTLH4DrbMti7rJ3GWXcEkAV5J-h3kir3KUfy7QSvxUP0fIHgAhNBShA3j6QP6O0ZcJU0EsMgIr_J8xnDlF2Cz7VU1OtAoZ8UJmDF4CVBgEFNDxmdvdmSCFLOS07Bw06xf0uj4o0L1i6hHG8llypuewwbs/w317-h640/Mars%20atmosphere.JPG" width="317" /></a><span style="text-align: left;"> </span></div><div><br /></div><div>This is quite important because carbon monoxide can be made to combust in oxygen by the reaction:</div><div><br /></div><div><span class="base" style="background: rgb(255, 255, 255); border: 0px; box-sizing: border-box; display: inline-block; font-family: "Times New Roman", serif; font-size: 18px; letter-spacing: -0.5px; margin: 0px; outline: 0px; padding: 0px; position: relative; white-space: nowrap; width: min-content;"><span class="mord" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">2</span><span class="mord mathnormal" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px 0.07153em 0px 0px; outline: 0px; padding: 0px; position: static;">C</span><span class="mord mathnormal" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px 0.02778em 0px 0px; outline: 0px; padding: 0px; position: static;">O</span><span class="mspace" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; margin: 0px 0.222222em 0px 0px; outline: 0px; padding: 0px; position: static;"></span><span class="mbin" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">+</span><span class="mspace" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; margin: 0px 0.222222em 0px 0px; outline: 0px; padding: 0px; position: static;"></span></span><span class="base" style="background: rgb(255, 255, 255); border: 0px; box-sizing: border-box; display: inline-block; font-family: "Times New Roman", serif; font-size: 18px; letter-spacing: -0.5px; margin: 0px 0px 3px; outline: 0px; padding: 0px; position: relative; white-space: nowrap; width: min-content;"><span class="strut" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; height: 0.83333em; margin: 0px; outline: 0px; padding: 0px; position: static; vertical-align: -0.15em;"></span><span class="mord" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;"><span class="mord mathnormal" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px 0.02778em 0px 0px; outline: 0px; padding: 0px; position: static;">O</span><span class="msupsub" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; margin: 0px; outline: 0px; padding: 2px 0px; position: relative;"><span class="vlist-t vlist-t2" style="background: transparent; border-collapse: collapse; border: 0px; box-sizing: border-box; display: inline-table; margin: 0px -2px 0px 0px; outline: 0px; padding: 0px; position: static; table-layout: fixed;"><span class="vlist-r" style="background: transparent; border: 0px; box-sizing: border-box; display: table-row; margin: 0px; outline: 0px; padding: 0px; position: static;"><span class="vlist" style="background: transparent; border: 0px; box-sizing: border-box; display: table-cell; height: 0.301108em; margin: 0px; outline: 0px; padding: 0px; position: relative; vertical-align: bottom;"><span style="background: transparent; border: 0px; box-sizing: border-box; display: block; height: 0px; margin: 0px 0.05em 0px -0.02778em; outline: 0px; padding: 0px; position: relative; top: -2.55em;"><span class="pstrut" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; height: 2.7em; margin: 0px; outline: 0px; overflow: hidden; padding: 0px; position: static; width: 0px;"></span><span class="sizing reset-size6 size3 mtight" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; font-size: 0.7em; margin: 0px; outline: 0px; padding: 0px; position: static;"><span class="mord mtight" style="background: transparent; border: 0px; box-sizing: border-box; font-size: 12.6px; margin: 0px; outline: 0px; padding: 0px; position: static;"><span class="mord mtight" style="background: transparent; border: 0px; box-sizing: border-box; font-size: 12.6px; margin: 0px; outline: 0px; padding: 0px; position: static;">2</span></span></span></span></span><span class="vlist-s" style="background: transparent; border: 0px; box-sizing: border-box; display: table-cell; font-size: 1px; margin: 0px; min-width: 2px; outline: 0px; padding: 0px; position: static; vertical-align: bottom; width: 2px;"></span></span><span class="vlist-r" style="background: transparent; border: 0px; box-sizing: border-box; display: table-row; margin: 0px; outline: 0px; padding: 0px; position: static;"><span class="vlist" style="background: transparent; border: 0px; box-sizing: border-box; display: table-cell; height: 0.15em; margin: 0px; outline: 0px; padding: 0px; position: relative; vertical-align: bottom;"><span style="background: transparent; border: 0px; box-sizing: border-box; display: block; height: 0px; margin: 0px; outline: 0px; padding: 0px; position: relative;"></span></span></span></span></span></span><span class="mspace" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; margin: 0px 0.277778em 0px 0px; outline: 0px; padding: 0px; position: static;"></span><span class="mrel" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">→</span><span class="mspace" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; margin: 0px 0.277778em 0px 0px; outline: 0px; padding: 0px; position: static;"></span></span><span class="base" style="background: rgb(255, 255, 255); border: 0px; box-sizing: border-box; display: inline-block; font-family: "Times New Roman", serif; font-size: 18px; letter-spacing: -0.5px; margin: 0px 0px 3px; outline: 0px; padding: 0px; position: relative; white-space: nowrap; width: min-content;"><span class="strut" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; height: 0.87777em; margin: 0px; outline: 0px; padding: 0px; position: static; vertical-align: -0.19444em;"></span><span class="mord" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">2</span><span class="mord mathnormal" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px 0.07153em 0px 0px; outline: 0px; padding: 0px; position: static;">C</span><span class="mord" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;"><span class="mord mathnormal" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px 0.02778em 0px 0px; outline: 0px; padding: 0px; position: static;">O</span><span class="msupsub" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; margin: 0px; outline: 0px; padding: 2px 0px; position: relative;"><span class="vlist-t vlist-t2" style="background: transparent; border-collapse: collapse; border: 0px; box-sizing: border-box; display: inline-table; margin: 0px -2px 0px 0px; outline: 0px; padding: 0px; position: static; table-layout: fixed;"><span class="vlist-r" style="background: transparent; border: 0px; box-sizing: border-box; display: table-row; margin: 0px; outline: 0px; padding: 0px; position: static;"><span class="vlist" style="background: transparent; border: 0px; box-sizing: border-box; display: table-cell; height: 0.301108em; margin: 0px; outline: 0px; padding: 0px; position: relative; vertical-align: bottom;"><span style="background: transparent; border: 0px; box-sizing: border-box; display: block; height: 0px; margin: 0px 0.05em 0px -0.02778em; outline: 0px; padding: 0px; position: relative; top: -2.55em;"><span class="pstrut" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; height: 2.7em; margin: 0px; outline: 0px; overflow: hidden; padding: 0px; position: static; width: 0px;"></span><span class="sizing reset-size6 size3 mtight" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; font-size: 0.7em; margin: 0px; outline: 0px; padding: 0px; position: static;"><span class="mord mtight" style="background: transparent; border: 0px; box-sizing: border-box; font-size: 12.6px; margin: 0px; outline: 0px; padding: 0px; position: static;"><span class="mord mtight" style="background: transparent; border: 0px; box-sizing: border-box; font-size: 12.6px; margin: 0px; outline: 0px; padding: 0px; position: static;">2</span></span></span></span></span><span class="vlist-s" style="background: transparent; border: 0px; box-sizing: border-box; display: table-cell; font-size: 1px; margin: 0px; min-width: 2px; outline: 0px; padding: 0px; position: static; vertical-align: bottom; width: 2px;"></span></span><span class="vlist-r" style="background: transparent; border: 0px; box-sizing: border-box; display: table-row; margin: 0px; outline: 0px; padding: 0px; position: static;"><span class="vlist" style="background: transparent; border: 0px; box-sizing: border-box; display: table-cell; height: 0.15em; margin: 0px; outline: 0px; padding: 0px; position: relative; vertical-align: bottom;"><span style="background: transparent; border: 0px; box-sizing: border-box; display: block; height: 0px; margin: 0px; outline: 0px; padding: 0px; position: relative;"></span></span></span></span></span></span><span class="mpunct" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">;</span><span class="mspace" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; margin: 0px 0.166667em 0px 0px; outline: 0px; padding: 0px; position: static;"></span><span class="mord" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">Δ</span><span class="mord mathnormal" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px 0.08125em 0px 0px; outline: 0px; padding: 0px; position: static;">H</span><span class="mspace" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; margin: 0px 0.277778em 0px 0px; outline: 0px; padding: 0px; position: static;"></span><span class="mrel" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">=</span><span class="mspace" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; margin: 0px 0.277778em 0px 0px; outline: 0px; padding: 0px; position: static;"></span></span><span class="base" style="background: rgb(255, 255, 255); border: 0px; box-sizing: border-box; display: inline-block; font-family: "Times New Roman", serif; font-size: 18px; letter-spacing: -0.5px; margin: 0px 0px 3px; outline: 0px; padding: 0px; position: relative; white-space: nowrap; width: min-content;"><span class="strut" style="background: transparent; border: 0px; box-sizing: border-box; display: inline-block; height: 1em; margin: 0px; outline: 0px; padding: 0px; position: static; vertical-align: -0.25em;"></span><span class="mord" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">−</span><span class="mord" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">5</span><span class="mord" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">6</span><span class="mord" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">9</span><span class="mord mathnormal" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px 0.03148em 0px 0px; outline: 0px; padding: 0px; position: static;">k</span><span class="mord mathnormal" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px 0.09618em 0px 0px; outline: 0px; padding: 0px; position: static;">J</span><span class="mord" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">/</span><span class="mord mathnormal" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">m</span><span class="mord mathnormal" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px; outline: 0px; padding: 0px; position: static;">o</span><span class="mord mathnormal" style="background: transparent; border: 0px; box-sizing: border-box; margin: 0px 0.01968em 0px 0px; outline: 0px; padding: 0px; position: static;">l</span></span></div><div><br /></div><div> This is not as high energy reaction as hydrogen or methane with oxygen but may be enough to provide sufficient thrust to slow down the craft to enable a soft landing via parachutes. </div><div><br /></div><div> We have then though a similar problem as with scramjet propulsion on Earth. The craft will be moving so fast there might not be enough time for combustion to take place. The problem is made worse because there is additional time that must be taken to separate out by filtration the carbon monoxide and oxygen from the carbon dioxide.</div><div><br /></div><div> Still, whether or not this problem can be solved, it is extremely important that this reaction be employed for ISRU once down on Mars. A criticism of the approach of SpaceX of landing the large Starship on Mars is the high energy requirements of producing the methane propellant requiring separating oxygen and hydrogen water(ice) in the soil by electrolysis.</div><div><br /></div><div> For a vehicle the size of the Starship Robert Zubrin has suggested it might take <a href="https://www.yahoo.com/news/elon-musk-plan-settle-mars-093002155.html" target="_blank">10 football fields of solar panels or even take a nuclear power plant</a>. However, when CO can be obtained from low energy filtration from the Martian atmosphere then free hydrogen for propulsion can be obtained by the reaction:</div><div><br /></div><div><span style="background-color: white; color: #212529;">CO + H</span><span style="background-color: white; bottom: -0.25em; box-sizing: border-box; color: #212529; line-height: 0; position: relative; vertical-align: baseline;">2</span><span style="background-color: white; color: #212529;">O → CO</span><span style="background-color: white; bottom: -0.25em; box-sizing: border-box; color: #212529; line-height: 0; position: relative; vertical-align: baseline;">2</span><span style="background-color: white; color: #212529;"> + H</span><span style="background-color: white; bottom: -0.25em; box-sizing: border-box; color: #212529; line-height: 0; position: relative; vertical-align: baseline;">2, </span><span style="background-color: white; color: #212529;"> </span><span class="mjx-base" style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; color: #666666; display: inline-block; white-space: nowrap;"><span class="mjx-mi" id="MJXc-Node-78730" style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; display: inline-block;"><span class="mjx-char MJXc-TeX-main-R" style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; display: block; padding-bottom: 0.372em; padding-top: 0.446em; white-space: pre;">Δ</span></span></span><span style="background-color: white; color: #212529;">H = -41 kJ mol</span><span style="background-color: white; box-sizing: border-box; color: #212529; line-height: 0; position: relative; top: -0.5em; vertical-align: baseline;">-1</span></div><div> </div><div> You can then get methane if that is the preferred fuel over hydrogen by reacting the free hydrogen with CO2 by the famous Sabatier reaction:</div><div><br /></div><div><span class="mwe-math-element" face="sans-serif" style="background-color: white; color: #202122; font-size: 14px;"><img alt="{\displaystyle {\ce {CO2{}+4H2->[{} \atop 400\ ^{\circ }{\ce {C}}][{\ce {pressure+catalyst}}]CH4{}+2H2O}}}" aria-hidden="true" class="mwe-math-fallback-image-inline" src="https://wikimedia.org/api/rest_v1/media/math/render/svg/9954c5b345addcf6421c02b5becd4db9e4dde1c8" style="border: 0px; display: inline-block; height: 6.509ex; margin-bottom: -0.646ex; margin-top: -0.398ex; vertical-align: -2.359ex; width: 40.514ex;" /></span><span face="sans-serif" style="background-color: white; color: #202122; font-size: 14px; padding-left: 1em;"> </span><span face="sans-serif" style="background-color: white; color: #202122; font-size: 14px;">∆</span><i style="background-color: white; color: #202122; font-family: sans-serif; font-size: 14px;">H</i><span face="sans-serif" style="background-color: white; color: #202122; font-size: 14px;"> = −165.0 kJ/mol</span></div><div> </div><div> So obtaining free O2 and CO from the Marian atmosphere by low energy filtration makes obtaining propellant for the return flight for manned missions much more feasible.</div><div><br /></div></span></div><h3 style="color: #333333; text-align: left;"><span style="font-family: inherit;">Financing a Commercial Approach to a Mars Sample Return Mission.</span></h3><div><span style="font-family: inherit;"> </span><span style="font-family: verdana;">If this is to be a fully commercial mission how is it to be funded?</span></div><div><span style="font-family: verdana;"><div><br /></div></span></div><div><span style="font-family: verdana;"><span> Recall back in 1997 the great interest </span>over the internet from people world-wide on the Mars Pathfinder mission. T<span style="background-color: white; color: #222222;">he Mars Pathfinder mission actually "broke the internet", with its sites getting up to 60+ million total hits per day, to the extent some mirror sites crashed or had to have access limited:</span></span></div><div><span style="font-family: verdana;"><br style="background-color: white; color: #222222;" /><span style="background-color: white; color: #222222;">Traffic on Mars</span><br style="background-color: white; color: #222222;" /><span style="background-color: white; color: #222222;">by Chuck Toporek</span><br style="background-color: white; color: #222222;" /><span style="background-color: white; color: #222222;">Asst. Managing Editor</span><br style="background-color: white; color: #222222;" /><span style="background-color: white; color: #222222;">Web Review</span><br style="background-color: white; color: #222222;" /><i style="background-color: white; color: #222222;">However, the most interesting and little known fact about the amount of traffic to the mirror sites comes from France, where the government actually pleaded with computer users to stop accessing the two Mars Pathfinder mirrors. You see, the phone systems in France carry all of the Internet traffic in the country, so when people started visiting the mirror sites at VisuaNet and Le Centre National D'Etudes Spatiales (CNES), they tied up the phone lines and basically disabled the country.</i><br style="background-color: white; color: #222222;" /><a href="http://mars.jpl.nasa.gov/MPF/press/webreview/index4.html" style="background-color: white; color: #2288bb; text-decoration-line: none;">http://mars.jpl.nasa.gov/MPF/press/webreview/index4.html</a><br style="background-color: white; color: #222222;" /></span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;"><span style="background-color: white; color: #222222;"> The web traffic to the NASA web site for the Mars Exploration Rovers was even more extraordinary, measuring in the billions of hits:</span><br style="background-color: white; color: #222222;" /><br style="background-color: white; color: #222222;" /><span style="background-color: white; color: #222222;">NASA’s Web Site for 2005</span><br style="background-color: white; color: #222222;" /><span style="background-color: white; color: #222222;">By Digital Trends Staff — January 7, 2005</span><br style="background-color: white; color: #222222;" /><i style="background-color: white; color: #222222;">The U.S. National Aeronautics and Space Administration Web portal continues to drive high traffic numbers — <b>more than 17 billion hits in 2004</b>, report both NASA and Speedera Networks, a leading global provider of on-demand distributed application hosting and content delivery services. Speedera delivers content from the space agency’s portal to visitors seeking access to the site from around the world. Popular events on the NASA Web site, including the ongoing Mars Exploration Rover mission entering its remarkable second year, as well as upcoming major projects such as the launch and comet encounter of NASA’s Deep Impact satellite mission in 2005, are expected to drive continued high levels of traffic, according to NASA officials.</i><br style="background-color: white; color: #222222;" /><a href="http://www.digitaltrends.com/computing/nasas-web-site-for-2005/" style="background-color: white; color: #2288bb; text-decoration-line: none;">http://www.digitaltrends.com/computing/nasas-web-site-for-2005/</a><br style="background-color: white; color: #222222;" /><br style="background-color: white; color: #222222;" /><span style="background-color: white; color: #222222;"> It was estimated there were 142 million visits to the site during this period. So the question is how much advertising could be sold for a site this well visited?</span></span></div><div><span style="font-family: verdana;"><span style="background-color: white; color: #222222;"><br /></span></span></div><div><span style="font-family: verdana;"><span style="background-color: white; color: #222222;"> It could be financed in the fashion of YouTube videos where the content creator is paid according to the number of views of the video:</span></span></div><div><div style="box-sizing: border-box; margin: 1em auto; max-width: var(--single-content-editorial-width); text-align: left;"><span style="font-family: verdana;"><span face="National2, helvetica neue, helvetica, -apple-system, BlinkMacSystemFont, ubuntu, roboto, noto, segoe ui, arial, sans-serif" style="color: #404345;"><span>How much do YouTubers make? 2023 facts and figures.<br /></span></span><span face="National2, helvetica neue, helvetica, -apple-system, BlinkMacSystemFont, ubuntu, roboto, noto, segoe ui, arial, sans-serif" style="color: #404345;"><span>Edited by:<br /></span></span><span face="National2, helvetica neue, helvetica, -apple-system, BlinkMacSystemFont, ubuntu, roboto, noto, segoe ui, arial, sans-serif" style="color: #404345;"><span>Erin Dunn </span></span><span face="National2, helvetica neue, helvetica, -apple-system, BlinkMacSystemFont, ubuntu, roboto, noto, segoe ui, arial, sans-serif" style="color: #404345;"><span>• </span></span></span><span face="National2, "helvetica neue", helvetica, -apple-system, BlinkMacSystemFont, ubuntu, roboto, noto, "segoe ui", arial, sans-serif" style="color: #404345;"><span style="font-family: verdana;">May 23, 2023</span><br /></span><i><span face="National2, "helvetica neue", helvetica, -apple-system, BlinkMacSystemFont, ubuntu, roboto, noto, "segoe ui", arial, sans-serif" style="color: #404345; font-size: 17px;">Curious about how much money YouTubers make per view? YouTubers make an average of $0.018 per ad view, according to Influencer Market Hub. Rates can range from $0.10 to $0.30 per ad view. </span><span face="National2, "helvetica neue", helvetica, -apple-system, BlinkMacSystemFont, ubuntu, roboto, noto, "segoe ui", arial, sans-serif" style="color: #404345; font-size: 17px;">However, the amount of money YouTube pays depends on a variety of factors, such as:</span></i></div><div style="box-sizing: border-box; margin: 1em auto; max-width: var(--single-content-editorial-width); text-align: left;"><span face="National2, "helvetica neue", helvetica, -apple-system, BlinkMacSystemFont, ubuntu, roboto, noto, "segoe ui", arial, sans-serif" style="color: #404345;"><div style="box-sizing: border-box; font-style: italic; margin: 1em auto; max-width: var(--single-content-editorial-width);"><span style="font-size: 17px;">• </span><span style="font-size: 17px;">The number of views your video receives</span><span style="font-size: 17px;">...</span></div><div style="box-sizing: border-box; margin: 1em auto; max-width: var(--single-content-editorial-width);"><span style="font-size: 17px;"><a href="https://www.creditkarma.com/income/i/how-much-do-youtubers-make">https://www.creditkarma.com/income/i/how-much-do-youtubers-make</a></span></div><div style="box-sizing: border-box; margin: 1em auto; max-width: var(--single-content-editorial-width);"><span style="font-family: verdana;"> The most successful YouTube millionaires however make even more money by partnering with advertisers on their channels. Then the financial backers of the mission could sell the rights for products to be associated with financing the mission.</span></div></span></div><div><span face="National2, helvetica neue, helvetica, -apple-system, BlinkMacSystemFont, ubuntu, roboto, noto, segoe ui, arial, sans-serif" style="color: #404345;"><span style="font-family: verdana;"> Robert Clark</span></span></div></div></div></span><p></p>Robert Clarkhttp://www.blogger.com/profile/16114043697010364282noreply@blogger.com1tag:blogger.com,1999:blog-7598615455712402973.post-6795855255158080762023-06-19T16:35:00.006-04:002023-06-23T14:45:35.490-04:00Towards a revolutionary advance in spaceflight: an all-liquid Ariane 6.<p style="text-align: center;"> <i>Copyright 2023 Robert Clark</i></p><p style="text-align: center;"><i><br /></i></p><p style="text-align: center;"></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjOpeqPX25V3JEFOU9ZTMFprlsWzny56B-I2u5e6IYBDxA6zmg8yEagJdanGA2G0ZbyiYGs3c4Frdw9Eoae2pLrEupLFFYtOsn4ulW2Q9JmJGtEBwdpz9D9WCtN0hZ_smXuAQtnlaMaGLJKyytnqhAZ8MNzsthcd7y5ZOip_3ZSCLaZrwBLNrzMQBUBAXs/s1344/Ariane%2062%20sans%20SRBs,%20twin%20Vulcains.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1344" data-original-width="312" height="697" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjOpeqPX25V3JEFOU9ZTMFprlsWzny56B-I2u5e6IYBDxA6zmg8yEagJdanGA2G0ZbyiYGs3c4Frdw9Eoae2pLrEupLFFYtOsn4ulW2Q9JmJGtEBwdpz9D9WCtN0hZ_smXuAQtnlaMaGLJKyytnqhAZ8MNzsthcd7y5ZOip_3ZSCLaZrwBLNrzMQBUBAXs/w162-h697/Ariane%2062%20sans%20SRBs,%20twin%20Vulcains.png" width="162" /></a></div><i><div style="text-align: center;"><i>Imagined Ariane 6 sans SRB's with twin Vulcains.</i></div></i><i><br /></i><p></p><p style="text-align: center;"><i><br /></i></p><p style="text-align: left;"><i> </i><b style="background-color: white; color: #222222; font-family: arial; font-size: large;">Abstract.</b></p><span style="font-family: arial;"> Most orbital rockets have payload fractions in the range of 3% to 4%. The Ariane 6 using 2 and 4 SRB’s, because of the large size of the SRB’s and because solids are so inefficient on both mass ratio and ISP, the two key components of the rocket equation, it will count among the worst rockets in history at a payload fraction of only 2%. <br /><br /> In contrast a two Vulcain Ariane 6 could have a payload fraction of 7% and a three Vulcain Ariane 6 could have a payload fraction of 7.5%. This is well-above what any other rocket has ever achieved in the history of space flight.<br /><br /> So how is an all-liquid Ariane 6 able to accomplish this? First, this version is based on the Ariane 5 core. The mass ratio for the Ariane 5 it turns out is quite extraordinary for a hydrogen+liquid oxygen(called “hydrolox”) stage at 16.3 to 1. This is in the range commonly seen by dense propellants. To use a colorful analogy, it’s like the ArianeSpace engineers in designing the Ariane 5 core found a way to make liquid hydrogen as dense as kerosene!<br /><br /> Obviously, this is not what happened. But they must have found a way to achieve extreme lightweighting of a hydrolox stage. To put this in perspective, the mass ratio of the famous Centaur hydrolox upper stage is at 10 to 1, achieved back in the 1960’s. And the Delta IV hydrolox core is at a quite ordinary 8.7 to 1 mass ratio. So the Ariane 5 core is about twice as good as the Delta IV core on this key mass ratio scale.<br /><br /> Because the Ariane 5 core has the high Isp of a hydrolox stage while achieving (somehow!) the high mass ratio of a dense propellant stage, it calculates out to have the highest delta-v of any rocket stage in the history of spaceflight.<br /><br /> Since delta-v is the single most important parameter for orbital rockets, you can legitimately argue the Ariane 5 core is the greatest rocket stage ever produced in the history of spaceflight.<br /><br /> The high 7.5% payload fraction of the all-liquid Ariane 6 would mean SpaceX would have to be chasing ArianeSpace rather than the other way around.<br /><br /><i> To put this advance in perspective, it would be like SpaceX using the very same Merlin engines and the very same propellant tanks, and the very same size Falcon 9, suddenly being able to change the Falcon 9 payload from 22 tons to 40 tons.</i><br /><br /> It will represent a paradigm shift in terms of the payloads that rockets will be expected to deliver to orbit.<br /><br /> Usually, when we think of a radical shift in rocket capability we imagine some great advance in engines such as nuclear, or some great advance in materials to greatly reduce tank weight. <br /><br /> Quite extraordinary is the the fact this radical increase in rocket capability can come from using currently existing engines and tanks.</span><div><span style="font-family: arial;"><br /></span></div><div><span style="font-family: arial;"><b><span style="font-size: medium;">Introduction.</span></b><br /></span><p><span color="rgba(0, 0, 0, 0.87)" style="font-family: arial;"><span color="rgba(0, 0, 0, 0.87)" style="background-color: white;"> Mitchell Burnside Clapp is an engineer and former Air Force officer who had been prominent in programs back-in-the-day to find low cost space access, such as the DC-X. Here, he was calculating some existent or previous space stages that just on the ideal delta-v parameter would have SSTO capability:</span></span></p><p><span color="rgba(0, 0, 0, 0.87)" style="font-family: arial;"><span color="rgba(0, 0, 0, 0.87)" style="background-color: white;"><br /></span></span></p><p>==================================================</p><div class="ObkkYd" style="-webkit-tap-highlight-color: transparent; align-items: baseline; color: rgba(0, 0, 0, 0.87); display: flex; flex-flow: row; font-family: Roboto, RobotoDraft, Helvetica, Arial, sans-serif; justify-content: space-between;"><div class="hLrx8" style="-webkit-tap-highlight-color: transparent; align-items: baseline; display: flex; flex-flow: row wrap; justify-content: flex-start; min-width: 0px;"><div class="ThqSJd" style="-webkit-tap-highlight-color: transparent; align-items: baseline; display: flex; flex-flow: row nowrap; justify-content: flex-start; padding: 16px 16px 16px 0px;"><h1 class="KPwZRb gKR4Fb" jsname="GNEpNe" style="-webkit-tap-highlight-color: transparent; background-color: white; color: #202124; display: inline-block; font-family: "Google Sans", Roboto, Arial, sans-serif; font-weight: 400; justify-content: space-between; line-height: 28px; margin: 0px; outline: none; padding: 0px; top: 0px; word-break: break-word; z-index: 1;"><html-blob style="-webkit-tap-highlight-color: transparent;"><span style="font-size: small;">Propellant density, scale, and lightweight structure</span></html-blob></h1><h1 class="KPwZRb gKR4Fb" jsname="GNEpNe" style="-webkit-tap-highlight-color: transparent; background-color: white; color: #202124; display: inline-block; font-family: "Google Sans", Roboto, Arial, sans-serif; font-weight: 400; justify-content: space-between; line-height: 28px; margin: 0px; outline: none; padding: 0px; top: 0px; word-break: break-word; z-index: 1;"><html-blob style="-webkit-tap-highlight-color: transparent;"><span style="font-size: small;"><br /></span></html-blob></h1><h1 class="KPwZRb gKR4Fb" jsname="GNEpNe" style="-webkit-tap-highlight-color: transparent; background-color: white; color: #202124; display: inline-block; font-family: "Google Sans", Roboto, Arial, sans-serif; font-weight: 400; justify-content: space-between; line-height: 28px; margin: 0px; outline: none; padding: 0px; top: 0px; word-break: break-word; z-index: 1;"><html-blob style="-webkit-tap-highlight-color: transparent;"><span style="font-size: small;">.</span></html-blob></h1><h1 class="KPwZRb gKR4Fb" jsname="GNEpNe" style="-webkit-tap-highlight-color: transparent; background-color: white; color: #202124; display: inline-block; font-family: "Google Sans", Roboto, Arial, sans-serif; font-weight: 400; justify-content: space-between; line-height: 28px; margin: 0px; outline: none; padding: 0px; top: 0px; word-break: break-word; z-index: 1;"><br /></h1><h1 class="KPwZRb gKR4Fb" jsname="GNEpNe" style="-webkit-tap-highlight-color: transparent; background-color: white; color: #202124; display: inline-block; font-family: "Google Sans", Roboto, Arial, sans-serif; font-weight: 400; justify-content: space-between; line-height: 28px; margin: 0px; outline: none; padding: 0px; top: 0px; word-break: break-word; z-index: 1;"><img alt="Mitchell Burnside Clapp's profile photo" data-atf="false" data-iml="255283.79999923706" role="presentation" src="https://lh3.googleusercontent.com/a/default-user=s40-c" style="-webkit-tap-highlight-color: transparent; background-color: transparent; border: none; color: rgba(0, 0, 0, 0.87); font-family: arial;" /></h1></div></div></div><div aria-label="Propellant desity, scale, and lightweight structure" role="list" style="-webkit-tap-highlight-color: transparent;"><section aria-expanded="true" class="BkrUxb" data-author="Mitchell Burnside Clapp" data-doc-id="IlrJM-q6RQkJ" data-is-first="true" data-subject="Propellant desity, scale, and lightweight structure" jsaction="VqL3Gc:xvWlrc;QvNAx:AHmuwe;JIbuQc:OOqk2e(onkYyb),OOqk2e(IgWJu),FUJCwf(OqWcW),Bmlfs(rKtXic),qHAave(k1xLRe);rcuQ6b:npT2md;DB0tFc:dvCNbf; keydown:hXsouf; click:mHokFf(A9KrYd),gfTIJc(yjbGtf),hXsouf" jscontroller="ywEdOe" role="listitem" style="-webkit-tap-highlight-color: transparent; border-bottom: 1px solid rgb(232, 234, 237); padding-left: 2px; padding-top: 8px;" tabindex="0"><div class="eH2Xlc" style="-webkit-tap-highlight-color: transparent; outline: none;" tabindex="-1"><div class="oXnYGc" style="-webkit-tap-highlight-color: transparent; display: flex;"><div class="X7AGAf" style="-webkit-tap-highlight-color: transparent; flex-grow: 1; min-width: 0px;"><div class="UZ2tvc" jsname="A9KrYd" style="-webkit-tap-highlight-color: transparent; color: rgba(0, 0, 0, 0.87);"><div class="NcB7hc" style="-webkit-tap-highlight-color: transparent; align-items: center; color: #5f6368; display: flex; height: 48px; justify-content: space-between;"><div class="LgTNRd" style="-webkit-tap-highlight-color: transparent; overflow: hidden; text-overflow: ellipsis; white-space: nowrap;"><span style="font-family: arial;"><h3 class="s1f8Zd" id="c1789" style="-webkit-tap-highlight-color: transparent; color: #202124; display: inline; font-weight: 500; letter-spacing: 0.25px; line-height: 20px; margin-bottom: 0px; margin-right: 16px; margin-top: 0px;">Mitchell Burnside Clapp</h3><span style="letter-spacing: 0.3px;">Jul 19, 1995, 3:00:00 AM</span></span></div></div></div><div aria-labelledby="c1789" class="ptW7te" jsname="yjbGtf" role="region" style="-webkit-tap-highlight-color: transparent; margin: 12px 0px; overflow: auto; padding-right: 20px;"><span style="font-family: arial;">There has been some speculation about Atlas being one of the<br style="-webkit-tap-highlight-color: transparent;" />lightest aerospace structures ever built. The thing that keeps<br style="-webkit-tap-highlight-color: transparent;" />it from being a single stage to orbit machine is its relatively<br style="-webkit-tap-highlight-color: transparent;" />heavy and low performance engines.</span><p style="-webkit-tap-highlight-color: transparent; color: rgba(0, 0, 0, 0.87);"><span style="font-family: arial;">I decided to examine the historical record on this issue and<br style="-webkit-tap-highlight-color: transparent;" />developed the table you see below. <b>All the weights are in<br style="-webkit-tap-highlight-color: transparent;" />thousands of pounds; the Ideal DV colum is in kft/sec</b>. Prop wt<br style="-webkit-tap-highlight-color: transparent;" />refers to the weight of propellants. The Isp numbers are<br style="-webkit-tap-highlight-color: transparent;" />referenced as far as possible to vacuum Isp. The engine data are<br style="-webkit-tap-highlight-color: transparent;" />from CPIA Revised Liquid Propellant Engine Manual (1972), and<br style="-webkit-tap-highlight-color: transparent;" />Rocketdyne, SEP, Aerojet, and Pratt and Whitney product<br style="-webkit-tap-highlight-color: transparent;" />information sheets. The vehicle weight data are from Isakowitz’<br style="-webkit-tap-highlight-color: transparent;" />Space Launch Systems, 1st Ed. Ideal DV is calculated from the<br style="-webkit-tap-highlight-color: transparent;" />rocket equation [DV = Isp * g * ln (gross/(gross-prop))]. The<br style="-webkit-tap-highlight-color: transparent;" />column labeled PMSMF refers to the Propulsion-Free Structural<br style="-webkit-tap-highlight-color: transparent;" />Mass Fraction, which refers to the weight of the stage after the<br style="-webkit-tap-highlight-color: transparent;" />engine is removed, divided by the gross weight. This residual<br style="-webkit-tap-highlight-color: transparent;" />weight includes the electronics, tankage, and so forth.</span></p><p style="-webkit-tap-highlight-color: transparent; color: rgba(0, 0, 0, 0.87);"><span style="font-family: arial;">Here are the data:</span></p><p style="-webkit-tap-highlight-color: transparent;"><span style="font-family: arial;"><span color="rgba(0, 0, 0, 0.87)">Stage Prop Wt Gross Wt Engine Wt Isp PFSMF Ideal DV</span><br style="-webkit-tap-highlight-color: transparent;" /><b><i><u><span color="rgba(0, 0, 0, 0.87)">Titan II Stg 1 260.0 269.0 3.258 287 2.13% </span><span style="color: red;">31.372</span></u></i></b><br style="-webkit-tap-highlight-color: transparent;" /><span color="rgba(0, 0, 0, 0.87)">Black Arrow Stg 1 28.7 31.1 1.426 250 2.99% 20.755</span><br style="-webkit-tap-highlight-color: transparent;" /><span color="rgba(0, 0, 0, 0.87)">Saturn V Stg 1 4584.0 4872.0 93.080 265 4.00% 24.114</span><br style="-webkit-tap-highlight-color: transparent;" /><span color="rgba(0, 0, 0, 0.87)">Titan III Stg 1 294.0 310.0 3.343 283 4.08% 26.959</span><br style="-webkit-tap-highlight-color: transparent;" /><span color="rgba(0, 0, 0, 0.87)">Titan IV Stg 1 340.0 359.0 3.343 283 4.36% 26.731</span><br style="-webkit-tap-highlight-color: transparent;" /><span color="rgba(0, 0, 0, 0.87)">Delta 6925 Stg 1 211.3 223.8 2.528 295 4.46% 27.383</span><br style="-webkit-tap-highlight-color: transparent;" /><span color="rgba(0, 0, 0, 0.87)">Atlas E 248.8 266.7 4.371 312 5.07% 27.073</span><br style="-webkit-tap-highlight-color: transparent;" /><b><i><u><span color="rgba(0, 0, 0, 0.87)">Saturn V Stg 2 993.0 1071.0 17.400 425 5.66% </span><span style="color: red;">35.821</span></u></i></b><br style="-webkit-tap-highlight-color: transparent;" /><span color="rgba(0, 0, 0, 0.87)">Zenit Stg 1 703.0 778.0 26.575 337 6.22% 25.364</span><br style="-webkit-tap-highlight-color: transparent;" /><span color="rgba(0, 0, 0, 0.87)">Titan III Stg 2 77.2 83.6 1.144 312 6.29% 25.796</span><br style="-webkit-tap-highlight-color: transparent;" /><b><i><u><span color="rgba(0, 0, 0, 0.87)">Saturn IB Stg 2 233.0 255.0 3.480 425 7.26% </span><span style="color: red;">33.504</span></u></i></b><br style="-webkit-tap-highlight-color: transparent;" /><span color="rgba(0, 0, 0, 0.87)">Titan II Stg 2 59.0 65.0 1.102 308 7.54% 23.611</span><br style="-webkit-tap-highlight-color: transparent;" /><span color="rgba(0, 0, 0, 0.87)">Saturn IB Stg 1 889.0 980.0 16.072 263 7.65% 20.111</span><br style="-webkit-tap-highlight-color: transparent;" /><u><b><i><span color="rgba(0, 0, 0, 0.87)">Ariane 5 Stg 1 342.0 375.0 3.630 430 7.83% </span><span style="color: red;">33.624</span></i></b><br style="-webkit-tap-highlight-color: transparent;" /><b><i><span color="rgba(0, 0, 0, 0.87)">Saturn 5 Stg 3 238.0 263.0 3.480 425 8.18% </span><span style="color: red;">32.179</span></i></b><br style="-webkit-tap-highlight-color: transparent;" /><b><i><span color="rgba(0, 0, 0, 0.87)">Energia Core 1810.0 1995.0 21.000 452 8.22% </span><span style="color: red;">34.583</span></i></b></u><br style="-webkit-tap-highlight-color: transparent;" /><span color="rgba(0, 0, 0, 0.87)">Zenit Stg 2 178.0 198.0 2.480 350 8.85% 25.816</span><br style="-webkit-tap-highlight-color: transparent;" /><span color="rgba(0, 0, 0, 0.87)">Black Arrow Stg 2 6.5 7.8 .531 265 9.52% 15.450</span><br style="-webkit-tap-highlight-color: transparent;" /><span color="rgba(0, 0, 0, 0.87)">Titan IV Stg 2 77.2 87.0 1.144 312 9.95% 21.919</span><br style="-webkit-tap-highlight-color: transparent;" /><span color="rgba(0, 0, 0, 0.87)">Delta 6925 Stg 2 13.4 15.4 .207 267 11.82% 17.416</span></span></p><p style="-webkit-tap-highlight-color: transparent; color: rgba(0, 0, 0, 0.87);"><span style="font-family: arial;">...</span></p><p style="-webkit-tap-highlight-color: transparent; color: rgba(0, 0, 0, 0.87);"><span style="font-family: arial;">7. There are several stages that have SSTO-class delta-V figures<br style="-webkit-tap-highlight-color: transparent;" />(anything over 30000 fps). The Titan II first stage can itself<br style="-webkit-tap-highlight-color: transparent;" />deliver 1400 pounds to low earth orbit as it sits, with no<br style="-webkit-tap-highlight-color: transparent;" />modifications to engine or structure. That’s pretty impressive,<br style="-webkit-tap-highlight-color: transparent;" />even if a load of propellant for it costs $2.5 miilion.</span></p><p style="-webkit-tap-highlight-color: transparent; color: rgba(0, 0, 0, 0.87);"><span style="font-family: arial;">==================================================</span></p><p style="-webkit-tap-highlight-color: transparent;"><span color="rgba(0, 0, 0, 0.87)" style="font-family: arial;"><a href="https://groups.google.com/g/sci.space.policy/c/PZgWB9WWhNw/m/gWAavQL8AAAJ">https://groups.google.com/g/sci.space.policy/c/PZgWB9WWhNw/m/gWAavQL8AAAJ</a></span></p><p style="-webkit-tap-highlight-color: transparent; color: rgba(0, 0, 0, 0.87);"><span style="font-family: arial;"> However, since the SSTO was dismissed as not worth-while an important implication of such high delta-v stages was missed: when the first stage gets such high delta-v, the upper stage can be much smaller to get the same payload to orbit.</span></p><p style="-webkit-tap-highlight-color: transparent; color: rgba(0, 0, 0, 0.87);"><span style="font-family: arial;"> <b>Or said another way, a high delta-v first stage gets high payload to orbit with just a small size upper stage. </b></span></p><p style="-webkit-tap-highlight-color: transparent; color: rgba(0, 0, 0, 0.87);"><span style="font-family: arial;"><b> </b>Of those high delta-v stages Burnside Clapp listed as of 1995, the Ariane 5 is the only one yet existent.<i> And in actuality its even much better than listed in the table.</i></span></p><p style="-webkit-tap-highlight-color: transparent; color: rgba(0, 0, 0, 0.87);"><span style="font-family: arial;"> You see, the Ariane 5 core had a forward skirt called the JAVE<span style="background-color: white; color: #222222;">("Jupe AVant Equipée") that transmitted the thrust of the two side boosters to the core. </span><span style="background-color: white; color: #222222;">Without the side boosters, this</span><span style="background-color: white; color: #222222;"> would be removed in our version. <a href="https://exoscientist.blogspot.com/2013/03/the-coming-sstos-multi-vulcain-ariane.html" target="_blank">The JAVE weighed 1,700 kg</a>. So lets calculate again the ideal delta-v without the JAVE. Note I'm using the lighter Ariane 5 "G" stage here, rather than the later "E" version, at a 158 ton propellant load and 12 ton dry mass. Removing the JAVE brings down the dry mass to 10.3 tons. I'll use the slightly better 434s vacuum Isp for the Vulcain now rather than the 430s Mitchell Burnside Clapp used in his 1995 calculation. Then the ideal delta-v is:</span></span></p><p style="-webkit-tap-highlight-color: transparent; color: rgba(0, 0, 0, 0.87);"><span style="background-color: white; color: #222222;"><span style="font-family: arial;">434*9.81Ln(1 + 158/10.3) = 11,900 m/s, or 39,000 ft/sec. </span></span></p><p style="-webkit-tap-highlight-color: transparent; color: rgba(0, 0, 0, 0.87);"><span style="background-color: white; color: #222222;"><b><span style="font-family: arial;"> This is by far the best ideal delta-v ever produced by any single rocket stage in the entire history of spaceflight, exceeding also the delta-v's for the separate rocket stages on the Falcon 9.</span></b></span></p><p style="-webkit-tap-highlight-color: transparent;"><span style="background-color: white;"><span style="color: #222222; font-family: arial;"> How were the Europeans able to produce such an extraordinary rocket stage? Firstly, they used hydrogen/oxygen(hydrolox) propellant on the core; this is known to produce the highest efficiency on the ISP scale of any chemical propellant. But this is well known and you see several stages among the highest listed used hydrolox. What's really extraordinary is the mass ratio, i.e., propellant fraction of the stage.</span></span></p><p style="-webkit-tap-highlight-color: transparent;"><span style="background-color: white;"><span style="color: #222222; font-family: arial;">The mass ratio is gross mass divided by dry mass and it is important for a rocket stage for it is used in the rocket equation to determine what is the delta-v it could achieve:</span></span></p><p style="-webkit-tap-highlight-color: transparent;"><span style="background-color: white;"><span style="color: #222222; font-family: arial;"></span></span></p><div class="separator" style="clear: both; text-align: center;"><span style="color: #222222; font-family: arial;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEioLHyYm6aUPVJrxGzqZkxMYnDKH4h8y23VPUq9S987g1y73cLsKfpn1ez7tiVc9pwKqTTBkRnCS8fXW-PKv3PRAb7qEkwK_uiZcAlq3BgiTLVWwbzNzrp1pkNcMck01kiT1oc2oh0HjAdCfSvHKj2pMJJo4DebPLB1ZLkhzEV48EnsMpLS-EXp_ouG/s709/rktpow.gif" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="533" data-original-width="709" height="301" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEioLHyYm6aUPVJrxGzqZkxMYnDKH4h8y23VPUq9S987g1y73cLsKfpn1ez7tiVc9pwKqTTBkRnCS8fXW-PKv3PRAb7qEkwK_uiZcAlq3BgiTLVWwbzNzrp1pkNcMck01kiT1oc2oh0HjAdCfSvHKj2pMJJo4DebPLB1ZLkhzEV48EnsMpLS-EXp_ouG/w400-h301/rktpow.gif" width="400" /></a></span></div><div class="separator" style="clear: both; text-align: center;"><span style="color: #222222; font-family: arial;"><br /></span></div><div class="separator" style="clear: both; text-align: left;"><span style="color: #222222; font-family: arial;"> </span></div><span style="color: #222222; font-family: arial;">The total mass of the stage would be 158 + 10.3 = 168.3 tons. Then the mass ratio would 168.3/10.3 = 16.3. As a point of comparison the famous Centaur upper stage was able to get a 10 to 1 mass ratio and this was considered a remarkable engineering achievement for a hydrolox rocket stage. </span><p></p><div style="-webkit-tap-highlight-color: transparent; text-align: left;"><span style="background-color: white;"><span style="color: #222222; font-family: arial;"> Hydrolox stages are able to get high ISP, but because hydrogen is such low density, the mass ratio is usually comparatively low. Dense propellant combinations such kerosene/oxygen(kerolox) are usually higher. For instance the mass ratio for the Atlas 5 kerolox first stage is about 16 to 1, and the Falcon 9 first stage is somewhat higher at about 20 to 1. But kerolox is about 3 times denser than hydrolox. So conceivably a kerolox stage such as the Atlas 5 or Falcon 9 using the same lightweighting methods as the Ariane 5 could get a mass ratio of 50 to 1!</span></span></div><p style="-webkit-tap-highlight-color: transparent;"><span style="background-color: white;"><span style="color: #222222; font-family: arial;"><i><b> </b>The mass ratio of the Ariane 5 core for a hydrogen stage is so remarkable that it should be used as a model for any stage hydrolox or kerolox<b>.</b></i><br /><br /></span></span></p><p style="-webkit-tap-highlight-color: transparent;"><span style="font-family: arial; font-size: medium;"><b>Cost of the side SRB's is the source of the high Ariane 6 pricing.</b></span></p><p style="-webkit-tap-highlight-color: transparent;"><span style="font-family: arial;"> That parameter of ideal delta-v that the Ariane 5 core has superiority on over any other rocket ever built suggests that that should be built upon and not disregarded. Instead what has been used on the Ariane 5 and Ariane 6 are solid stages that are among the worst on this key parameter. Because solids are pressure-fed meaning the entire propellant tank has to operate as the combustion chamber requiring thick tank walls, they usually have poor mass ratio, despite the solids propellants higher density. Worse, the other key parameter in the rocket equation ISP is also among the worst with solids. </span></p><p style="-webkit-tap-highlight-color: transparent;"><span style="font-family: arial;"> If it were only small solid side boosters used with the Ariane 5 and Ariane 6 then this would not have the severe reducing effect on the rocket efficiency that they did have. But instead the side rockets used on the Ariane 5 and 6 were huge in comparison to other side boosters used for example with the Atlas 5 and Delta IV, which were commonly only ~1/10th the size of the booster core stage.</span></p><p style="-webkit-tap-highlight-color: transparent;"><span style="font-family: arial;"> My speculation here, but I think the Space Shuttle design is what influenced ArianeSpace to use such large solid side boosters. Perhaps it was not known at the time when the Ariane 5 was first being designed but the Space Shuttle was a financial disaster. Such large side boosters are also used on the SLS which is also a financial disaster. The huge solid boosters used in both contributed to that.</span></p><p style="-webkit-tap-highlight-color: transparent;"><span style="font-family: arial;"> The newly designed solids on the Ariane 6 make the situation worse. Their size is about the size of the entire core stage of the Ariane 6, and the fact they use carbon-fiber make them more expensive. To understand how expensive is that use of carbon-fiber for the solids note the reason SpaceX decided to move away from carbon-fiber to steel for the StarShip:</span></p><p style="background-color: #fcfdfe; border: 0px; margin: 0px; padding: 7px 0px;"><span style="font-family: arial;"><span style="color: #333333;">Why SpaceX Abandoned Carbon Fiber.</span><br /><span style="color: #333333;">…</span><br /><em style="color: #333333;">The other concern was cost. SpaceX determined that it would spend upwards of $130,000 per ton to use carbon fiber as the primary rocket body material. On the other hand, it would spend just $2,500 per ton for stainless steel. It doesn’t take a mathematician to figure out that spending 50 times as much on carbon fiber would put considerable strain on the Starship project.</em><br /><span style="color: #2365b0;">https://markets.rockwestcomposites.com/we-now-know-why-spacex-abandoned-carbon-fiber</span></span></p><p style="background-color: #fcfdfe; border: 0px; color: #333333; margin: 0px; padding: 7px 0px;"><span style="font-family: arial;"> To provide an estimate of how bad is the cost issue against the Ariane 6 solids in comparison to just using an additional Vulcain, note the €75 million cost of the two SRB version of the Ariane 6 compared to the €115 million of the four SRB version. Then, as a first order estimate, we can take the cost of two SRB’s as €40 million. But the cost of a single Vulcan is only €10 million! So the two SRB’s planned for the base version costs 4 times as much as just adding a second Vulcain!</span></p><p style="background-color: #fcfdfe; border: 0px; color: #333333; margin: 0px; padding: 7px 0px;"><span style="font-family: arial;">Therefore, again as a first order estimate, we can take the cost of a Ariane 6 with no SRB’s by subtracting off the estimated €40 million for the two SRB’s to get a no SRB price of only €35 million.<i>Then the price of the two SRB's is more than the price of the entire rest of the rocket.</i> So adding on a Vulcain at €10 million would give a price of €45 million, about $50 million. Note this compares quite favorably with the current $67 million cost of the Falcon 9 new.</span></p><p style="background-color: #fcfdfe; border: 0px; color: #333333; margin: 0px; padding: 7px 0px;"><span style="font-family: arial;"> Further indication of how expensive are the Ariane 6 SRB's is found by comparing to other carbon-fiber, also called graphite-fiber, SRB's. The GEM 63 are carbon-fiber solid side boosters have about a 50 ton propellant load and cost estimated in the range $5 to $7 million.Then we can estimate the Ariane 6 SRB's to cost three times more to bring them to $15 to $21 million each, in the price range of the estimate you get from comparing the Ariane 6 two SRB and Ariane 6 four SRB pricing.</span></p><p style="background-color: #fcfdfe; border: 0px; color: #333333; margin: 0px; padding: 7px 0px;"><span style="font-family: arial;"><a href="https://exoscientist.blogspot.com/2023/05/who-in-european-space-will-ask.html" target="_blank"> There needs to be a discussion among the European space community about the use of these large expensive boosters when the same can be accomplished much more cheaply by just using additional Vulcain engines on the core.</a></span></p><p style="background-color: #fcfdfe; border: 0px; color: #333333; margin: 0px; padding: 7px 0px;"><span style="font-family: arial; font-size: medium;"><b>Payload Calculation for a Two Vulcain Ariane 6. </b></span></p><p style="border: 0px; color: #333333; margin: 0px; padding: 7px 0px;"><span style="font-family: arial;"><span style="background-color: #fcfdfe;"> </span><span style="background-color: white;">In the blog post, <a href="https://exoscientist.blogspot.com/2018/02/multi-vulcain-ariane-6.html" target="_blank">"Multi-Vulcain Ariane 6"</a>, I estimated about 11 tons to LEO using a two Vulcain, no SRB version for the Ariane 6. </span></span><span style="background-color: white; color: #222222; text-align: justify;"><span style="font-family: arial;">Note though I was originally trying to find a lower cost approach to the Ariane 6, so I actually used the Ariane 5 core. BUT because of my thrust constraints I chose to use the original, somewhat smaller version the Ariane 5 "G" core, rather than the later "E" version, at 12 ton dry mass and 158 propellant mass.</span></span></p><span style="background-color: white;"><span style="font-family: arial;"><span style="color: #222222; text-align: justify;"> For the upper stage, again because of limited take off thrust constraints I did not use the current ESC-A cryogenic upper stage of the Ariane 5 at ~19 ton gross mass, nor the ~30 ton cryogenic upper stage of the Ariane 6. I also did not like that the ESC-A had such a poor mass ratio at only 5 to 1. I used instead the Ariane 4's H10 cryogenic upper stage:</span><br style="color: #222222; text-align: justify;" /><br style="color: #222222; text-align: justify;" /><span style="color: #222222; text-align: justify;">ARIANE 4 STAGE 3</span><br style="color: #222222; text-align: justify;" /><span style="color: #222222; text-align: justify;">Specifications are given in H10/H10+/H10-3 order.</span><br style="color: #222222; text-align: justify;" /><span style="color: #222222; text-align: justify;">Designation: H10/H10+/H10-3</span><br style="color: #222222; text-align: justify;" /><span style="color: #222222; text-align: justify;">Engine: single cryogenic open cycle SEP HM-7B</span><br style="color: #222222; text-align: justify;" /><span style="color: #222222; text-align: justify;">Length: 10.73 m/11.05 m/11.05 m</span><br style="color: #222222; text-align: justify;" /><span style="color: #222222; text-align: justify;">Diameter: 2.60 m</span><b><br style="color: #222222; text-align: justify;" /><span style="color: #222222; text-align: justify;">Dry mass: 1,200 kg/1,240 kg/1,240 kg, excluding interstage 2/3</span></b><br style="color: #222222; text-align: justify;" /><span style="color: #222222; text-align: justify;">Oxidizer: liquid oxygen</span><br style="color: #222222; text-align: justify;" /><span style="color: #222222; text-align: justify;">Fuel: liquid hydrogen</span><br style="color: #222222; text-align: justify;" /><span style="color: #222222; text-align: justify;"><b>Propellant mass: 10,800 kg/11,140 kg/11,860 kg</b></span><br style="color: #222222; text-align: justify;" /><span style="color: #222222; text-align: justify;">Thrust: 63 kN vac/63.2 kN vac/64.8 kN vac</span><br style="color: #222222; text-align: justify;" /><span style="color: #222222; text-align: justify;">http://www.braeunig.us/space/specs/ariane.htm</span><br style="color: #222222; text-align: justify;" /><br style="color: #222222; text-align: justify;" /><span style="color: #222222; text-align: justify;"> Note that in addition to being lighter this has a much better mass ratio at over 10 to 1, rivaling the famous Centaur upper stage.</span></span><span style="color: #222222; text-align: justify;"><span style="font-family: arial;"> I also assumed the Vulcain thrust could be ramped up ca. 9% as was shown possible with the SSME's and the RS-68 engine on the Delta IV rocket. Then I asserted for the Vulcain likely the same would hold, as they are all hydrolox engines. </span></span></span></div><div aria-labelledby="c1789" class="ptW7te" jsname="yjbGtf" role="region" style="-webkit-tap-highlight-color: transparent; margin: 12px 0px; overflow: auto; padding-right: 20px;"><span style="background-color: white;"><span style="color: #222222; text-align: justify;"><span style="font-family: arial;"> But a commenter to my blog cited a report giving estimated Ariane 6 values that estimated a 104 tons sea level thrust, so 208 tons for two, already held for the latest version: </span></span><a data-ved="2ahUKEwjOwviUns3_AhXFrYkEHR0UAeMQFnoECBUQAQ" href="https://ec.europa.eu/research/participants/documents/downloadPublic?documentIds=080166e5b8c8416f&appId=PPGMS" jsaction="rcuQ6b:npT2md" jscontroller="M9mgyc" jsname="qOiK6e" ping="/url?sa=t&source=web&rct=j&url=https://ec.europa.eu/research/participants/documents/downloadPublic%3FdocumentIds%3D080166e5b8c8416f%26appId%3DPPGMS&ved=2ahUKEwjOwviUns3_AhXFrYkEHR0UAeMQFnoECBUQAQ" rel="noopener" style="-webkit-tap-highlight-color: rgba(0, 0, 0, 0.1); color: #1a0dab; font-family: Roboto, arial, sans-serif; font-size: small; outline: 0px; white-space: nowrap;" target="_blank"><h3 class="LC20lb MBeuO DKV0Md" style="display: inline-block; font-size: 20px; font-weight: 400; line-height: 1.3; margin: 18px 0px 3px; padding: 5px 0px 0px;">Launcher analysis and cost benefits</h3></a></span></div><div aria-labelledby="c1789" class="ptW7te" jsname="yjbGtf" role="region" style="-webkit-tap-highlight-color: transparent; margin: 12px 0px; overflow: auto; padding-right: 20px;"><div class="Z26q7c UK95Uc jGGQ5e" data-snf="x5WNvb" data-snhf="0" style="color: #202124; contain: layout paint; flex: 0 0 auto; font-family: Roboto, arial, sans-serif; font-size: 14px; overflow: hidden;"><div class="yuRUbf" style="font-size: small; line-height: 1.58; white-space: nowrap;"><div class="B6fmyf byrV5b Mg1HEd" style="-webkit-box-align: center; -webkit-box-direction: normal; -webkit-box-orient: horizontal; align-items: center; display: flex; flex-direction: row; 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height: 18px; margin-left: 8px; margin-top: 16px; position: relative; visibility: visible;"><div data-bsextraheight="0" data-frm="true" data-isdesktop="true" data-movewtractions="true" data-ved="2ahUKEwjOwviUns3_AhXFrYkEHR0UAeMQ2esEegQIFRAJ" jscontroller="exgaYe" jsdata="l7Bhpb;_;BMzPBk cECq7c;_;BMzPBo"><div aria-label="About this result" class="iTPLzd rNSxBe lUn2nc" jsaction="RvIhPd" jsname="I3kE2c" role="button" style="cursor: pointer; left: 0px; line-height: 16px; outline: 0px; padding-bottom: 20px; padding-right: 12px; position: absolute; top: 0px; width: 28px; z-index: 1;" tabindex="0"><span class="D6lY4c mBswFe" jsname="czHhOd" style="border-radius: 11px; height: 22px; position: absolute; width: 22px;"><span class="xTFaxe z1asCe SaPW2b" jsname="Bil8Ae" style="background-color: white; color: #4d5156; display: inline-block; fill: currentcolor; height: 18px; line-height: 18px; position: relative; top: 2px; width: 18px;"><svg focusable="false" viewbox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M12 8c1.1 0 2-.9 2-2s-.9-2-2-2-2 .9-2 2 .9 2 2 2zm0 2c-1.1 0-2 .9-2 2s.9 2 2 2 2-.9 2-2-.9-2-2-2zm0 6c-1.1 0-2 .9-2 2s.9 2 2 2 2-.9 2-2-.9-2-2-2z"></path></svg></span></span></div><span data-ved="2ahUKEwjOwviUns3_AhXFrYkEHR0UAeMQh-4GegQIFRAK" jsname="zOVa8" style="background-color: white;"></span></div></div></div></div></div><div class="Z26q7c UK95Uc" data-sncf="1" data-snf="nke7rc" style="color: #202124; contain: layout paint; flex: 0 0 auto; font-family: Roboto, arial, sans-serif; font-size: 14px; overflow: hidden;"><div class="VwiC3b yXK7lf MUxGbd yDYNvb lyLwlc lEBKkf" style="-webkit-box-orient: vertical; -webkit-line-clamp: 2; color: #4d5156; display: -webkit-box; margin-bottom: 0px; overflow: hidden; padding-top: 0px;"><span style="background-color: white;">No 638719. <span style="color: #5f6368; font-weight: bold;">Launcher analysis and cost benefits</span>. Max <span style="color: #5f6368; font-weight: bold;">Calabro</span> (TIA). Emmanuella <span style="color: #5f6368; font-weight: bold;">Gizzi</span> (AVIO). Ref. Ares(2018)1042920 - 23/02/2018 </span></div></div></div><div aria-labelledby="c1789" class="ptW7te" jsname="yjbGtf" role="region" style="-webkit-tap-highlight-color: transparent; margin: 12px 0px; overflow: auto; padding-right: 20px;"><span style="background-color: white; color: #222222; text-align: justify;"><span style="font-family: arial;"><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/a/AVvXsEi_sn7jBDidTBiboNJ-EDF_Vzus9D4_mxrJhoodpobiPypHK_TCYg9Tj6A7-qct0RlU5uL-w7eRpxxhy8FtxvhbyHIWktancZH9BNaC1MxKNPrsO67IXw1CxK7HTUKyVbguXKrocH2ys-78dRrcyrO8SzfZB74zcrtuyDG6qqOYjcsN8o-znUwQ8G3F" style="margin-left: 1em; margin-right: 1em;"><img alt="" data-original-height="567" data-original-width="698" height="416" src="https://blogger.googleusercontent.com/img/a/AVvXsEi_sn7jBDidTBiboNJ-EDF_Vzus9D4_mxrJhoodpobiPypHK_TCYg9Tj6A7-qct0RlU5uL-w7eRpxxhy8FtxvhbyHIWktancZH9BNaC1MxKNPrsO67IXw1CxK7HTUKyVbguXKrocH2ys-78dRrcyrO8SzfZB74zcrtuyDG6qqOYjcsN8o-znUwQ8G3F=w511-h416" width="511" /></a></div><br /><br /></span></span></div><div aria-labelledby="c1789" class="ptW7te" jsname="yjbGtf" role="region" style="-webkit-tap-highlight-color: transparent; margin: 12px 0px; overflow: auto; padding-right: 20px;"><div style="text-align: justify;"><span style="color: #222222; font-family: arial;"><span style="background-color: white;"> If that is the case then I don't have to assume the Vulcain 2.1 thrust ramped up.</span></span></div><p style="border: 0px; color: #333333; margin: 0px; padding: 7px 0px;"><span style="background-color: white; font-family: arial;"> But even without a higher thrust level Vulcain, we could take a smaller propellant load of ca. 140 tons for the Ariane 6 core so it could still have sufficient thrust for takeoff. Since this is only about a 10% reduced propellant load for the first stage it would be a relatively small reduction in payload.</span></p><p style="border: 0px; color: #333333; margin: 0px; padding: 7px 0px;"><span style="background-color: white; font-family: arial;"> While I used the smaller, earlier Ariane 4 H10 upper stage because of my reduced thrust, we can now use the higher efficiency and thrust Vinci engine rather than the original HM-7B on this upper stage. The Vinci has a 180 kiloNewton vacuum thrust and 457s vacuum Isp. But using a slightly longer nozzle we can give it the 465.5 vacuum Isp of the RL10-B2. <a href="https://twitter.com/ToughSf/status/1513185037255995392?s=20" target="_blank">Remarkably with a sufficiently long nozzle we can give an upper stage hydrolox engine a vacuum Isp in the 480+s range.</a> </span><span style="background-color: white; color: #0f1419; white-space: pre-wrap;"><span style="font-family: arial;">However, we'll use in our calculations the Isp number proven possible with currently in use engines of a 465.5s vacuum Isp.</span></span></p><p style="border: 0px; color: #333333; margin: 0px; padding: 7px 0px;"><span style="background-color: white; color: #0f1419; white-space: pre-wrap;"><span style="font-family: arial;"> As for the dry mass of the core with a second Vulcain, we removed the JAVE subtracting off 1,700 kg from the dry mass. Adding on a second Vulcain adds on 1,800 kg, bringing the dry mass back to about the original 12 tons. </span></span></p><p style="border: 0px; color: #333333; margin: 0px; padding: 7px 0px;"><span style="background-color: white; color: #0f1419; white-space: pre-wrap;"><span style="font-family: arial;"> However, another consideration is the doubled thrust might require thickened tank walls.<a href="https://exoscientist.blogspot.com/2013/03/the-coming-sstos-multi-vulcain-ariane.html" target="_blank"> I estimated in an earlier blog post that the increased thrust might require an additional 1,000 kg for the thicker tank walls.</a> However, it should be noted the supported weight that needs to be carried above the core with a smaller upper stage and smaller payload mass is half as big as that of the Ariane 5. So advanced structural analysis programs need to be applied to find the needed degree of tank strengthening and added weight to the dry mass. </span></span></p><p style="border: 0px; color: #333333; margin: 0px; padding: 7px 0px;"><span style="background-color: white; color: #0f1419; white-space: pre-wrap;"><span style="font-family: arial;"> Still at most 1,000 kg needs to be added to the dry mass according to my prior estimate and this results in a proportionally small reduction in the payload mass. Then for this first order estimate we'll take simply 12,000 kg as the dry mass.</span></span></p><p style="border: 0px; color: #333333; margin: 0px; padding: 7px 0px;"><span style="background-color: white; color: #0f1419; font-family: arial; white-space: pre-wrap;"> Now use the payload estimator at SilverbirdAstronautics.com giving the results:</span></p><p style="border: 0px; margin: 0px; padding: 7px 0px;"><span style="color: #0f1419; font-family: arial;"></span></p><div class="separator" style="clear: both; text-align: center;"><span style="color: #0f1419; font-family: arial;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg1BMR-2nt8HeEl6HrxwxlXm3XNC6-tmHx9Y7Ohtyfd8qE8mgyEmL4F7ooo1ep8rThXrrJxlgQAsOHuR-MlTye5W-yo6woLeUWl2V9wDHgQVU-ZvP42c5APtECPJr5oO-HAmpXS-fGiZmpbnCIcFP9hR48dn9I0nQtKjp9lz9DB7dKxSEfbB3KA0Mzk/s2532/Ariane%20payload%201.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="2532" data-original-width="1170" height="995" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg1BMR-2nt8HeEl6HrxwxlXm3XNC6-tmHx9Y7Ohtyfd8qE8mgyEmL4F7ooo1ep8rThXrrJxlgQAsOHuR-MlTye5W-yo6woLeUWl2V9wDHgQVU-ZvP42c5APtECPJr5oO-HAmpXS-fGiZmpbnCIcFP9hR48dn9I0nQtKjp9lz9DB7dKxSEfbB3KA0Mzk/w460-h995/Ariane%20payload%201.jpg" width="460" /></a></span></div><div class="separator" style="clear: both; text-align: center;"><span style="color: #0f1419; font-family: arial;"><br /></span></div><div class="separator" style="clear: both; text-align: center;"><span style="color: #0f1419; font-family: arial;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjZJSCXqzz39-yuDjgOeofa_j-_iyIPJwJ9kVTHkApnxhG5k-VKj2mqvsPs4VUd1qbS11qgcEWJOECElXveysb-USqCT3XhIlMFK43mO3-QjWS5bCu8glzJjoYDu9UWQzlhZUULi1Gi-CTi1seH3MvTG3fkeHZtGYSq-6iEkaHrkyi1YZeriIcmqPCv/s2532/Ariane%20payload%202.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="2532" data-original-width="1170" height="1018" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjZJSCXqzz39-yuDjgOeofa_j-_iyIPJwJ9kVTHkApnxhG5k-VKj2mqvsPs4VUd1qbS11qgcEWJOECElXveysb-USqCT3XhIlMFK43mO3-QjWS5bCu8glzJjoYDu9UWQzlhZUULi1Gi-CTi1seH3MvTG3fkeHZtGYSq-6iEkaHrkyi1YZeriIcmqPCv/w471-h1018/Ariane%20payload%202.jpg" width="471" /></a></span></div><span style="color: #0f1419; font-family: arial;"><br /><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: left;"> The payload to LEO calculated is 14,000 kg, exceeding the ~10 ton LEO payload of the Ariane 6 version with two SRB's by 40%.</div><div class="separator" style="clear: both; text-align: left;"><br /></div><div class="separator" style="clear: both; text-align: left;"> For the payload to geosynchronous transfer orbit, change the apogee to 35,700 km. The result is:</div><div class="separator" style="clear: both; text-align: left;"><br /></div><div class="separator" style="clear: both; text-align: left;"><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjHoD52pwUhltMKlYCc5PoSsUwY7OiEnfuAJcUk1mc8emlyCD2BfGA0GkCBmTAGkMO-foo9n7i8oQGshSTCk2u6gC_xCnA4TRHzxO1OGR2EkmwQn1041TQZPBOSy_Cgw0ccoPydQO5e674Y1ZfAIPAl7dN8hfrsGP1m_FhIhPcASORJqfnCHx1jW0tL/s2532/GTO%20payload.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="2532" data-original-width="1170" height="1021" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjHoD52pwUhltMKlYCc5PoSsUwY7OiEnfuAJcUk1mc8emlyCD2BfGA0GkCBmTAGkMO-foo9n7i8oQGshSTCk2u6gC_xCnA4TRHzxO1OGR2EkmwQn1041TQZPBOSy_Cgw0ccoPydQO5e674Y1ZfAIPAl7dN8hfrsGP1m_FhIhPcASORJqfnCHx1jW0tL/w471-h1021/GTO%20payload.png" width="471" /></a></div><br /> </div><div class="separator" style="clear: both; text-align: left;"><br /></div><div class="separator" style="clear: both; text-align: left;"> The calculated payload to GTO of 6,652 kg is nearly 50% higher than the 4,500 kg GTO payload of the Ariane 6 version with two SRB's.</div><div class="separator" style="clear: both; text-align: left;"><br /></div><div class="separator" style="clear: both; text-align: left;"> </div></span><b style="background-color: #fcfdfe; color: #333333; font-family: arial; font-size: large;">Payload Calculation for a Three Vulcain Ariane 6. </b></div><div aria-labelledby="c1789" class="ptW7te" jsname="yjbGtf" role="region" style="-webkit-tap-highlight-color: transparent; margin: 12px 0px; overflow: auto; padding-right: 20px;"><span style="font-family: arial;"><span style="color: #333333;"> A three Vulcain format for an all-liquid Ariane 6 is actually preferred. The reason is you don't have such a thrust limitation as the two Vulcain case.This allows you to choose a larger upper stage resulting in a higher payload. <br /></span></span><p style="border: 0px; margin: 0px; padding: 7px 0px;"><span style="font-family: arial;"> I have presented the two Vulcain case here and in some previous postings because of the low development cost, <a href="https://exoscientist.blogspot.com/2023/05/who-in-european-space-will-ask.html" target="_blank">less than $200 million</a>. Indeed, it most likely could be done for <a href="https://exoscientist.blogspot.com/2023/06/towards-every-european-countrys-own.html" target="_blank">less than $100 million</a>. </span></p><p style="border: 0px; margin: 0px; padding: 7px 0px;"><span style="font-family: arial;"> However, adding two additional Vulcains will require a higher development cost. It still likely will be in the few hundred million dollars range, well less than the multi-billion dollar development cost of the current version of the Ariane 6. </span></p><p style="border: 0px; margin: 0px; padding: 7px 0px;"><span style="font-family: arial;"> Again a key consideration is added tank wall thickness needed for the tripled thrust. <a href="https://exoscientist.blogspot.com/2013/03/the-coming-sstos-multi-vulcain-ariane.html" target="_blank">In a prior blog post</a>, I discussed a rocket that had been proposed by Northrup Grumman, the Liberty rocket that would use a shuttle derived SRB as a first stage, a la the Ares I rocket, and an Ariane 5 core as an upper stage. </span></p><p style="border: 0px; margin: 0px; padding: 7px 0px;"><span style="font-family: arial;"> As described in this video, the SRB to be used would have had a thrust 12 times that of the Vulcain yet the increased thickness of the tanks on the Ariane 5 core would only need to be 50%:</span></p><p style="border: 0px; margin: 0px; padding: 7px 0px;"></p><div class="separator" style="clear: both; text-align: center;"><iframe allowfullscreen="" class="BLOG_video_class" height="317" src="https://www.youtube.com/embed/Hl_A7SF_TsM" width="382" youtube-src-id="Hl_A7SF_TsM"></iframe></div><br /><span style="font-family: arial;"> As the tank mass of the Ariane 5 core is in the range of 4 tons, this would mean the increased tank mass would have needed to be in the range of 2 tons. Since the three Vulcain format would mean far less less thrust than that of the Liberty rocket, the increased tank mass would be less than this. So we'll take the additional core mass as a max of 2,000 beyond that of the additional 3,600 kg for the added two Vulcains. </span><p></p><p style="border: 0px; margin: 0px; padding: 7px 0px;"><span style="font-family: arial;"> Since we have higher thrust we'll use the larger Ariane 5 "E" core at 170 propellant load and 14 dry mass. Subtracting off again the 1,700 kg for the JAVE, while adding on 3,600 for the two added Vulcains and 2,000 kg for the thickened tank walls brings the dry mass to about 18,000 kg. But because we have much more liftoff thrust with three Vulcains we can use much larger upper stages, such as the currently planned 30 ton hydrolox upper stage of the Ariane 6, or even larger 40 ton or 50 ton hydrolox stages.</span></p><p style="border: 0px; margin: 0px; padding: 7px 0px;"><span style="font-family: arial;"> We'll take our upper stage as 50 tons propellant load with a Centaur-like 10 to 1 mass ratio, so a 5 ton dry mass, a la the ULA Centaur V. We'll use three Vinci engines on the upper stage to give a thrust of 540 kN and assume a RL10-like 465.5s Isp. Then the input page on the SilverbirdAstonautics.com payload estimator appears as:</span></p><p style="border: 0px; margin: 0px; padding: 7px 0px;"></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgltM2fWgyzp-1s8fGLqau0VSMAwtE_YkS7mAS4CH41bm36nvlVqU0HGSnc_DHT4zOnlMaT63UmgPuw50yH4z8R4RbSw-j1aV0jvGJF8LpgqPV_eZWpgAXgSTSFCcml7Dq3QDY_n1SWFIsuntX8UrhmkqdY3yDC_rmrbIpLH4UTlOlxLwQ67LXCmbJNCgE/s2532/image_123986672.JPG" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="2532" data-original-width="1170" height="861" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgltM2fWgyzp-1s8fGLqau0VSMAwtE_YkS7mAS4CH41bm36nvlVqU0HGSnc_DHT4zOnlMaT63UmgPuw50yH4z8R4RbSw-j1aV0jvGJF8LpgqPV_eZWpgAXgSTSFCcml7Dq3QDY_n1SWFIsuntX8UrhmkqdY3yDC_rmrbIpLH4UTlOlxLwQ67LXCmbJNCgE/w398-h861/image_123986672.JPG" width="398" /></a></div><div class="separator" style="clear: both; text-align: center;"><br /></div><p style="border: 0px; margin: 0px; padding: 7px 0px;"><br /></p>The payload to LEO is estimated as:<p></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhMW6KHkNDFsf-Mr9RrSb6wCirquAfzDchd5e5jY_I7p6j3coRIAK91DGHw6Hyr-6nKwE1vYqu66oq7qXvXVLNJ5VKtyyfBHCic9-0HZp0_sq2REoHsPApjuf-gYcYo1xTvuJx7nG-6HlzjYpDyFvTfPufM1D6gSh-1ThzSo5P5fJALbWZPBSyeXGQLROc/s2532/image_123986672%20(2).JPG" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="2532" data-original-width="1170" height="833" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhMW6KHkNDFsf-Mr9RrSb6wCirquAfzDchd5e5jY_I7p6j3coRIAK91DGHw6Hyr-6nKwE1vYqu66oq7qXvXVLNJ5VKtyyfBHCic9-0HZp0_sq2REoHsPApjuf-gYcYo1xTvuJx7nG-6HlzjYpDyFvTfPufM1D6gSh-1ThzSo5P5fJALbWZPBSyeXGQLROc/w385-h833/image_123986672%20(2).JPG" width="385" /></a></div><br /><p style="border: 0px; margin: 0px; padding: 7px 0px;"><br /><span style="font-family: arial;">And the GTO payload is:</span></p><p style="border: 0px; margin: 0px; padding: 7px 0px;"></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEismIlFbZ68bGyBHEav6jlGYh5yJfPLgv_H_Tr2cIy1ejv-2wyZ-jiHS7MxOIBGWwVw3_QTtqnRmC6M3JmVmYorjhqfTnL8md6QLXFg_YRlscp4GIx_NVYxESiaboHQ9cQrr_BEnRq-aN0ium5BeuoSraPHnwAu5fxA3rlXAGBcza6unL5FkBKWXy3o--0/s2532/image_123986672%20(1).JPG" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="2532" data-original-width="1170" height="812" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEismIlFbZ68bGyBHEav6jlGYh5yJfPLgv_H_Tr2cIy1ejv-2wyZ-jiHS7MxOIBGWwVw3_QTtqnRmC6M3JmVmYorjhqfTnL8md6QLXFg_YRlscp4GIx_NVYxESiaboHQ9cQrr_BEnRq-aN0ium5BeuoSraPHnwAu5fxA3rlXAGBcza6unL5FkBKWXy3o--0/w375-h812/image_123986672%20(1).JPG" width="375" /></a></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial;"><br /></span></div><div class="separator" style="clear: both; text-align: left;"><span style="font-family: arial;"> This is slightly less than the LEO payload of the Falcon 9, but about the same payload of the Falcon 9 for the lucrative GTO market.</span></div><div class="separator" style="clear: both; text-align: left;"><br /></div><div class="separator" style="clear: both; text-align: left;"><span style="font-family: arial;"> It is likely cheaper also than the Falcon 9 new. The reason is the Ariane 6 core and upper stage<span style="background-color: #fcfdfe; color: #333333;"> </span><span style="background-color: #fcfdfe; color: #333333;">without SRB's </span>is about <span style="background-color: #fcfdfe; color: #333333;">€35 million, and the bulk of this price would be the core since the upper stage is such small relative size. For instance the price of the Falcon 9 is 3/4ths due to the first stage compared to the second stage. </span></span></div><div class="separator" style="clear: both; text-align: left;"><span style="font-family: arial;"><span style="background-color: #fcfdfe; color: #333333;"><br /></span></span></div><div class="separator" style="clear: both; text-align: left;"><span style="font-family: arial;"><span style="background-color: #fcfdfe; color: #333333;"> Then using a </span>50% larger upper stage for the Ariane 6 might add another </span><span style="background-color: #fcfdfe; color: #333333; font-family: arial;">€5 million to the price, bringing it to </span><span style="background-color: #fcfdfe; color: #333333; font-family: arial;">€40 million. Then the two additional Vulcains would bring the price to </span><span style="background-color: #fcfdfe; color: #333333; font-family: arial;">€60 million, a bit less than the $67 million price of the Falcon 9 new.</span></div><div class="separator" style="clear: both; text-align: left;"><span style="background-color: #fcfdfe; color: #333333; font-family: arial;"><br /></span></div><div class="separator" style="clear: both; text-align: left;"><span style="background-color: #fcfdfe; color: #333333; font-family: arial;"><span style="font-size: medium;"><b>The All-Liquid Ariane 6 as a Revolutionary Advance in Spaceflight.</b></span></span></div><div class="separator" style="clear: both; text-align: left;"><span style="background-color: #fcfdfe; color: #333333; font-family: arial;"><br /></span></div><div class="separator" style="clear: both; text-align: left;"><span style="background-color: #fcfdfe; color: #333333; font-family: arial;"> A key parameter for rocket efficiency that rocket engineers always use is </span><em style="background-color: #fcfdfe; color: #333333; font-family: arial;">payload fraction</em><span style="background-color: #fcfdfe; color: #333333; font-family: arial;">. For almost all rockets this is in the range of 3% to 4%. But because of those huge SRB’s the Ariane 6 uses, its payload fraction counts as among the worst in history at only in the range of 2%. But the two Vulcain</span><span style="background-color: #fcfdfe; color: #333333; font-family: arial;"> </span><em style="background-color: #fcfdfe; color: #333333; font-family: arial;">no SRB</em><span style="background-color: #fcfdfe; color: #333333; font-family: arial;"> </span><span style="background-color: #fcfdfe; color: #333333; font-family: arial;">version of the Ariane 6 would be in the range of 7%! And the three Vulcain no SBR version would be in the range of 7.5%.</span></div><p></p><div class="separator" style="clear: both;"><p style="background-color: #fcfdfe; border: 0px; color: #333333; margin: 0px; padding: 7px 0px;"><strong><span style="font-family: arial;">On this key parameter rocket engineers use to rate orbital rockets the all-liquid Arianes would literally be the best rockets in the history of space flight with no other rocket even coming close.</span></strong></p><p style="background-color: #fcfdfe; border: 0px; color: #333333; margin: 0px; padding: 7px 0px;"><span style="font-family: arial;">They would literally be a paradigm shift in rocket efficiency. Other launch companies would have to strive to reach their level of efficiency. And most simply could not.</span></p><p style="background-color: #fcfdfe; border: 0px; color: #333333; margin: 0px; padding: 7px 0px;"><span style="font-family: arial;"><i> To put this advance in perspective, it would be like SpaceX using the very same Merlin engine and the very same propellant tanks, and the very same size Falcon 9, suddenly being able to change the Falcon 9 payload from 22 tons to 40 tons. </i></span></p><p style="background-color: #fcfdfe; border: 0px; color: #333333; margin: 0px; padding: 7px 0px;"><span style="font-family: arial;">Plus, while being nearly twice as good as the Falcon 9 on this key parameter the all-liquid Ariane 6 would also be cheaper!</span></p><p style="background-color: #fcfdfe; border: 0px; color: #333333; margin: 0px; padding: 7px 0px;"><span style="font-family: arial;"><br /></span></p><p style="background-color: #fcfdfe; border: 0px; color: #333333; margin: 0px; padding: 7px 0px;"><span style="font-family: arial;"> Robert Clark</span></p></div><p style="border: 0px; margin: 0px; padding: 7px 0px;"><span style="font-family: arial;"><br /></span></p><p style="border: 0px; margin: 0px; padding: 7px 0px;"><span style="font-family: arial;"><br /></span></p><p style="-webkit-tap-highlight-color: transparent;"><span style="background-color: white; font-family: arial;"> </span></p></div></div></div></div></section></div></div>Robert Clarkhttp://www.blogger.com/profile/16114043697010364282noreply@blogger.com1tag:blogger.com,1999:blog-7598615455712402973.post-82438242569301482552023-06-08T09:24:00.002-04:002023-06-08T09:24:40.327-04:00Towards Every European Country's Own Crewed Spaceflight.<p style="text-align: center;"> <i>Copyright 2023 Robert Clark</i></p><p style="text-align: center;"><i><br /></i></p><p style="background-color: #fcfdfe; border: 0px; color: #333333; font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 13px; margin: 0px; padding: 7px 0px;"> In my blog post, <a href="https://exoscientist.blogspot.com/2023/05/who-in-european-space-will-ask.html" target="_blank">"Who in European space will ask the impertinent question: How much would it cost to add a second Vulcain to the Ariane 5/6?"</a>, I noted the reason why ESA is using the more expensive solid rocket boosters rather than just adding another Vulcain is political. The majority of the development funds and<i> the</i> <i>revenues from launches</i> go to those ESA member states producing the solids, more than the amount going to all the other member states combined. If those solids were no longer used that majority of funds would drop down to nearly nothing.</p><p style="background-color: #fcfdfe; border: 0px; color: #333333; font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 13px; margin: 0px; padding: 7px 0px;"> So that‘s a severe political problem for the other member states who might want to go to an all-liquid propulsion form for the Ariane 6. But there may be a way to get there anyway. If a member state wanted to spend their own money to build a prototype Ariane 6 core using two Vulcains how could other member states prevent it? It’s their own money. They can spend it anyway they want. Remember quite key to why this is approach is preferable is because how low cost the development costs would be. The example of JAXA adding a second hydrolox engine to the H-II core for ca. $200 million(27 billion Yen) demonstrates this:</p><p style="background-color: #fcfdfe; border: 0px; color: #333333; font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 13px; margin: 0px; padding: 7px 0px;"><span class="postimg"><img alt="mzb4ck08l83b1.jpg?width=1536&format=pjpg&auto=webp&v=enabled&s=c8bf665395fce7e3a5e8d2a0caa0ddf1a0de5233" src="https://preview.redd.it/mzb4ck08l83b1.jpg?width=1536&format=pjpg&auto=webp&v=enabled&s=c8bf665395fce7e3a5e8d2a0caa0ddf1a0de5233" style="margin: 7px 0.5em 7px 0px; max-width: 98%; vertical-align: middle;" /></span></p><p style="background-color: #fcfdfe; border: 0px; color: #333333; font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 13px; margin: 0px; padding: 7px 0px;"><br /></p><p style="background-color: #fcfdfe; border: 0px; color: #333333; font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 13px; margin: 0px; padding: 7px 0px;"> In point of fact it’s probably even cheaper than this just to add the second engine. The transition from the H-IIa to the H-IIb actually involved multiple systems:</p><p><img alt="xm39gnp0m83b1.png?width=2160&format=png&auto=webp&v=enabled&s=57ba69032a229d81825c27d8617314d980e2a087" src="https://preview.redd.it/xm39gnp0m83b1.png?width=2160&format=png&auto=webp&v=enabled&s=57ba69032a229d81825c27d8617314d980e2a087" style="background-color: #fcfdfe; color: #333333; font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 13px; margin: 7px 0.5em 7px 0px; max-width: 98%; vertical-align: middle;" /></p><p style="background-color: #fcfdfe; border: 0px; color: #333333; font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 13px; margin: 0px; padding: 7px 0px;"> Then conceivably the development cost just for adding the engine only might be only $100 million or less. But when there is no multi-billion dollar development cost, any of the ESA member states could afford to add an additional engine to an Ariane 5/6 core on their own. It’s so low that even the member states that already spent billions developing the solids could also adapt a Ariane core to have two Vulcains at this low cost.</p><p style="background-color: #fcfdfe; border: 0px; color: #333333; font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 13px; margin: 0px; padding: 7px 0px;"> At such a low development cost and each per rocket cost being even lower than the Falcon 9 each ESA member state could have their own independent all-liquid Ariane launchers. And each ESA member state could have their own independent manned flight capable rockets.</p><p style="background-color: #fcfdfe; border: 0px; color: #333333; font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 13px; margin: 0px; padding: 7px 0px;"> Robert Clark</p>Robert Clarkhttp://www.blogger.com/profile/16114043697010364282noreply@blogger.com0tag:blogger.com,1999:blog-7598615455712402973.post-25593876816695300512023-05-19T15:45:00.001-04:002023-05-19T15:45:39.384-04:00Who in European space will ask the impertinent question: How much would it cost to add a second Vulcain to the Ariane 5/6?<p style="text-align: center;"> <i>Copyright 2023 Robert Clark</i></p><p style="text-align: center;"><span style="text-align: left;"> </span></p><p style="text-align: left;"><b>ArianeSpace Needs to Transition to Reusability to Survive.</b></p><p style="text-align: left;"> European space advocates have been lamenting that there seems to be no near term route to keeping up with SpaceX, getting reusable launchers, and towards achieving manned space flight. However, in point of fact ESA already has the components to form a launcher comparable to the Falcon 9 <i>and at lower price</i>, while keeping pace with SpaceX in reusability, and in manned spaceflight.</p><p style="text-align: left;"> All it would require is someone, anyone in the Europeans space community to ask the impertinent question, "How much would it cost to add a 2nd Vulcain to the Ariane 5/6?"</p><p style="text-align: left;"> For once that question is asked, and ArianeSpace forced to answer honestly, they would have to admit it could be done for only a development cost in the range of only ~$200 million. But then it would become <i>obvious</i> how to proceed.</p><p style="text-align: left;"> First, note that the Ariane 6 that was planned to compete with the SpaceX Falcon 9 has been pushed back to 2024, when its original launch date was in 2020, extending the time where SpaceX is cornering the market. Note also the Ariane 6 will not be reusable. In fact ArianeSpace has admitted<a href="https://europeanspaceflight.com/europe-will-introduce-a-reusable-launch-vehicle-in-the-2030s-says-arianespace-ceo/" target="_blank"> they won't be fielding a reusable launcher until the 2030's. </a></p><p style="text-align: left;"> ULA was driven to the brink of bankruptcy by denying the importance of reusability. There is little doubt the same will happen to ArianeSpace if they wait a decade to field a reusable vehicle. Independent European space observers have also made this point about the choice of the non-reusable Ariane 6:</p>Europe’s lack of rocket ‘audacity’ leaves it scrambling in the space race<br />European policymakers want to stop SpaceX from dominating the launch market.<br />BY JOSHUA POSANER<br />JANUARY 15, 2021 12:28 PM CET 6 MINUTES READ<br /><i>That 2014 decision haunts French Economy Minister Bruno Le Maire, who keeps a warning of that moment on his desk.<br />“The European space adventure is magnificent, but in 2014 there was a fork in the road, and we didn’t take the right path,” Le Maire told a conference last September. “We should have made the choice of the reusable launcher. We should have had this audacity.”</i><br /><a href="https://www.politico.eu/article/europe-arianespace-rocket-space-race/">https://www.politico.eu/article/europe-arianespace-rocket-space-race/</a><div><br /></div><div><b> The <i>Fast</i> Route to Reusability.</b></div><div><b><br /></b></div><div> The problem with reusability for the Ariane 5 and 6 is they use solids for a large portion of their takeoff thrust. These large side boosters also make up a large portion of the cost. In fact, the situation has actually gotten worse with the Ariane 6. But the Space Shuttle program demonstrated you don't save on reuse with solid side boosters. By the time you fish the SRB's out of the ocean, tow them to port, transport them from port back to the manufacturing facility, clean them out from all the burnt on combustion products, and then finally refill them with propellant, the cost is no better than just using new ones to begin with. A little thought makes it easy to see why. Solid side boosters are just a filled in metal pipe. The cost of that metal pipe is small compared to all the <i>processing</i> involved in making the SRB. Keeping the same metal pipe but <i>increasing</i> all the needed steps for processing does not reduce the cost of the SRB.</div><div><br /></div><div> So to get the low cost reusable rocket you have to dispense with the SRB's. Necessarily that means you have to use additional liquid-fueled core engines. Then is adding an additional core engine a multi-billion dollar, or euro, development? </div><div><i><br /></i></div><div><i> No! I was quite startled to find JAXA was able to add an additional hydrolox engine to the H-II first stage for only an approx. $200 million development cost.</i></div><div><i><br /></i></div><div> See the highlighted passage in this article where the cost to add another engine to the H-II was only 27 billion Yen, about $200 million: </div><div> </div><div><div class="separator" style="clear: both; text-align: center;"><a href="https://pbs.twimg.com/media/Fvd7gOTX0AEutgM?format=jpg&name=large" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="800" data-original-width="600" height="800" src="https://pbs.twimg.com/media/Fvd7gOTX0AEutgM?format=jpg&name=large" width="600" /></a></div><br /><br /><div> But that means instead of the multi-billion current development cost of the Ariane 6, the same could have been accomplished for just a few hundred million and would also have been reusable! I made this point here:</div><div><br /></div><div><div>Multi-Vulcain Ariane 6.</div><div><a href="https://exoscientist.blogspot.com/2018/02/multi-vulcain-ariane-6.html">https://exoscientist.blogspot.com/2018/02/multi-vulcain-ariane-6.html</a></div></div><div><br /></div><div> Thus the importance of asking that impertinent question of ArianeSpace, "How much to add an additional Vulcain to the Ariane 5/6?"</div><div><br /></div><div><b>WHY Are the Far More Expensive SRB's Used Rather then the Cheaper Liquid-fueled Engines? </b></div><div><b><br /></b></div><div><div> Knowledgeable ESA observers have been aware for awhile now that the ESA policies for distributing funds and costs to the differing member states do not result in the most cost effective vehicles. It’s a policy called geographical-return that requires member states costs to be apportioned by some set proportion of the billion dollar development costs. So if some member states have been contributing some large proportion of the costs through solid side boosters, that cost continues to be part of the development for new rockets or upgrades.</div><div><br /></div><div> The governments of the member states regard this as a good thing because it helps to keep active, and paid, the space industries and space industry employees in their countries. But another key reason why some member states like the funds for the ESA to go to develop solid rocket side boosters is because those funds help also to develop solid rockets for their defense programs. So rather than those countries having to pay the entire cost of the solid rocket missiles in their defense programs on their own, some portion of that is actually paid for by the ESA in developing solid rocket side boosters for space launchers.</div><div><br /></div><div> You can see why there is a great incentive for those member states, which have great influence on the direction and funding choices for the ESA, to continue to want to use solid rocket boosters in <i>all</i> launchers produced by the ESA.</div><div><br /></div><div> But the stunning fact is how much more expensive the solids are for the Ariane 6 than just adding another Vulcain engine! <a href="https://www.nasaspaceflight.com/2020/07/esa-ariane-6-second-half-2021/" target="_blank">The latest cost figures for the Ariane 6 are the €75M for the two SRB version and €115M for the four SRB version</a>. </div><div><br /></div><div> This suggests, as a first order estimate, that we can take the cost of two SRB’s as €40M. But the cost of a single Vulcan is only €10 million! So the two SRB’s on the Ariane 6 base version costs 4 times more than an additional Vulcain!<b> Therefore, again as a first order estimate, we can take the cost of a two Vulcain Ariane 6 <i>with no SRB’s</i> as only €45 million, ~$50 million. This compares quite favorably to current $67 million cost of the Falcon 9.</b></div><div><br /></div><div> The reason why this isn’t done can not be attributed to some supposed multi-billion development cost to add an additional Vulcain to the Ariane core. Actually, it’s the current plan for the Ariane 6 with the newly developed solids, new upper stage, and new Vinci engine whose development cost is in the $4+ billion range. It’s really quite stunning to realize the same could have been accomplished at only a ~$200 development cost simply by adding another Vulcain to the Ariane 5 core, using the same original cryogenic upper stage. Nearly a factor of 20 times cheaper!</div><div><br /></div><div> But nobody knows this because nobody asks that one simple question, “How much would it cost to add a second Vulcain to the Ariane 5/6?”</div><div><br /></div><div> Now, once you have the all-liquid Ariane 6<i> that costs even cheaper than the Falcon 9</i>, you can also keep up with SpaceX in reducing price by reusability by also reusing the core stage via powered landing a la the F9 booster. Again, the solids in the current Ariane 6 version would not save on reusing them as the Space Shuttle program abundantly showed. So that huge €40 million cost just for the SRB’s on the Ariane 6(more than the cost of the entire rest of the rocket!) out of the total €75 million would be fixed no matter how many times you wanted to reuse the core.</div><div><br /></div><div> It might be argued that even a fully throttled down single Vulcain would have too much thrust for a hovering landing. Actually, this is the case also with the Falcon 9. It uses what SpaceX calls "hover-slam" for landing. The thrust is precisely timed so the booster just reaches 0 velocity as it touches down. Actually, I'm not a fan of "hover-slam". Much better for the Ariane case would be to use two Vinci engines for the landing only. It is designed to be air-startable and restartable. <a href="https://en.wikipedia.org/wiki/Vinci_(rocket_engine)" target="_blank">It weighs without the nozzle extension for vacuum use only 160 kg. </a>So two would weigh only 320kg on the first stage. It's use would allow true <i>hovering</i> landing for the first stage.</div><div><br /></div><div><b>Three Vulcains on the Ariane 5/6 Match the Falcon 9 in Payload at a Lower Price.</b></div><div><br /></div><div> The two Vulcain Ariane 5/6 would have lower payload than the Falcon 9. But it would be quite competitive for the lucrative <a href="https://en.wikipedia.org/wiki/Geostationary_transfer_orbit" target="_blank">geosynchronous transfer orbit(GTO)</a> used by many communications satellites, at ~6,000 kg to GTO <i>at lower price than the F9</i>. The F9 is at about 8,000 kg to GTO. But most satellites don't need this full capacity anyway.</div><div><br /></div><div> However, if we used three Vulcains we could then match the Falcon 9 in payload <i>and still be at lower price. </i>This comes from again using the first order estimate of<i> </i>€40 million for the two SRB's. So the Ariane 6 <i>with no SRB's</i> would be €35 million, as a first order estimate. So adding on two Vulcains would be €55 million, as a first order estimate. But this is still less than the $67 million price for the Falcon 9.</div><div><br /></div><div> In an upcoming blog post I'll discuss further the three Vulcain case showing it can match the Falcon 9 in payload. Intriguingly, by using multiple copies of such 3 Vulcain cores, I estimate 4 to 6, you can also get a 'superheavy' lift vehicle capable of 100-tons to LEO, a 'moon rocket'. Using multiple copies of already existing cores allows you to get the 'superheavy' lift at far less development cost than the $20 billion of the SLS, or the $10 billion of the ill-conceived Superheavy/Starship.</div><div><br /></div><div><b> Manned Launchers.</b></div><div><b><br /></b></div><div> Finally, in regards to manned launchers, just use the all-liquid Ariane 6 since you no longer have the safety issues of using SRB’s on manned launchers.</div></div><div><b><br /></b></div><div> </div><div> Robert Clark<br /><p style="text-align: left;"><br /></p></div></div>Robert Clarkhttp://www.blogger.com/profile/16114043697010364282noreply@blogger.com4tag:blogger.com,1999:blog-7598615455712402973.post-19942060728759796872023-04-08T20:50:00.004-04:002023-04-09T17:41:01.368-04:00SuperHeavy+Starship have the thermal energy of the Hiroshima bomb, Page 2: shattered windows and flying shrapnel.<p style="text-align: center;"><span style="font-family: inherit;"> Copyright 2023 Robert Clark</span></p><p style="text-align: left;"><span style="font-family: inherit;"> In the blog post, <a href="https://exoscientist.blogspot.com/2023/03/superheavystarship-have-thermal-energy.html" target="_blank">"SuperHeavy+Starship have the thermal energy of the Hiroshima bomb"</a>, I noted the SuperHeavy/Starship launch potentially can be damaging to people and property if it explodes. </span></p><p style="text-align: left;"><span style="font-family: inherit;"> I was using an exclusion radius though of only 2 miles, 3.2 km based on this hazard notice: </span></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiY_wdgop8X_zz_8xmWip0WI74UW2z6aS9TYqBlduY86jg6W69AUyehQ7J7QEaTDvr-H8Y355oIuAMI1KQTLnEV4PH71JgoLWh2XnqcSNrFg4XF5UUutnja1a4PYT7vfkGOFHnrFxTwUWs7YTKwAvjk6jEqstBvRhfLm7wQKQkUg5eMe-STsTCPJYQP/s800/Starship%20hazard%20area.jpg" style="margin-left: 1em; margin-right: 1em;"><span style="font-family: inherit;"><img border="0" data-original-height="800" data-original-width="610" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiY_wdgop8X_zz_8xmWip0WI74UW2z6aS9TYqBlduY86jg6W69AUyehQ7J7QEaTDvr-H8Y355oIuAMI1KQTLnEV4PH71JgoLWh2XnqcSNrFg4XF5UUutnja1a4PYT7vfkGOFHnrFxTwUWs7YTKwAvjk6jEqstBvRhfLm7wQKQkUg5eMe-STsTCPJYQP/w488-h640/Starship%20hazard%20area.jpg" width="488" /></span></a></div><span style="font-family: inherit;"><br /></span><p style="text-align: left;"><span style="font-family: inherit;"> However, this FAA report on page 22 puts the exclusion zone around the launch pad at about 5 mile radius:</span></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgyvOF7nRnALRd8LDE1Q5lKDCcPf86PNcJORZtOOuOTIPTKCWQ4zCbI227Gd_9muZ62QOssJO7avPka0BMs0NLiPDF2ZGbFqp_u2xP79WmHqQFlqeSrCvcw4OrDqhwLFHHBl_3TN_L5XcYzrz6b3VThYWyoxhM_yDXuGaCjZmx1dEUV4c8Q8uxnI5F0/s640/Safety-zone-ver2.jpg" style="margin-left: 1em; margin-right: 1em;"><span style="font-family: inherit;"><img border="0" data-original-height="422" data-original-width="640" height="422" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgyvOF7nRnALRd8LDE1Q5lKDCcPf86PNcJORZtOOuOTIPTKCWQ4zCbI227Gd_9muZ62QOssJO7avPka0BMs0NLiPDF2ZGbFqp_u2xP79WmHqQFlqeSrCvcw4OrDqhwLFHHBl_3TN_L5XcYzrz6b3VThYWyoxhM_yDXuGaCjZmx1dEUV4c8Q8uxnI5F0/w640-h422/Safety-zone-ver2.jpg" width="640" /></span></a></div><p style="text-align: left;"><a href="https://www.faa.gov/space/stakeholder_engagement/spacex_starship/media/Draft_PEA_for_SpaceX_Starship_Super_Heavy_at_Boca_Chica.pdf"><span style="font-family: inherit;">https://www.faa.gov/space/stakeholder_engagement/spacex_starship/media/Draft_PEA_for_SpaceX_Starship_Super_Heavy_at_Boca_Chica.pdf</span></a></p><p><span style="font-family: inherit;"> This is about about how far away Starship launch watchers are on South Padre Island when watching the launch from outside. It’s also the distance where space launch reporters such as Tim Dodd the “Everyday Astronaut” and others report on the Starship launches from hotel rooms on South Padre Island:</span></p><span style="font-family: inherit;">SpaceX Starship: Slo-mo SN9 flight video shows explosion in stunning detail SpaceX's Starship tackled its latest "hop test" — and it didn't end well.<br />BY MIKE BROWN<br />FEB. 3, 2021. <i>Ryan Chylinski, co-founder of Cosmic Perspective, tells Inverse he and his team were on a hotel balcony on South Padre Island during the launch — around five miles away. “We could certainly feel the rumble of the Raptors [the craft's engines] at this distance," he says. "And that explosion shockwave, wow!” he adds.</i><br /><a href="https://www.inverse.com/innovation/spacex-starship-sn9-flight">https://www.inverse.com/innovation/spacex-starship-sn9-flight</a><br /><br /> It's also uncomfortably close to the distance to Port Isabel, TX at 6 to 7 miles away, a town of about 5 thousand people. <br /></span><p><span style="font-family: inherit;"> However, even 5 miles is likely to still not be a safe distance based on other large explosions at the kiloton level such as the Texas City disaster:</span></p><span style="font-family: inherit;">April 16, 1947: Ship Explosion Ignites 3-Day Rain of Fire and Death.<br /><i>…It shattered all the windows in Texas City and half of those in Galveston, 10 miles away. Some debris reached an altitude of nearly 3 miles before falling back to earth. Two airplanes circling overhead were blown apart by the heavy shrapnel. A one-ton piece of the ship's propeller shaft landed 2½ miles away. Other pieces sailed 5 miles.</i><br /><a href="https://www.wired.com/2009/04/april-16-1947-ship-explosion-ignites-3-day-rain-of-fire-and-death-2/">https://www.wired.com/2009/04/april-16-1947-ship-explosion-ignites-3-day-rain-of-fire-and-death-2/</a></span><p><span style="font-family: inherit;"> The Texas City explosion was at the approx. 3 kilotons of TNT level. The N-1 Soviet rocket explosion was at about the 1.2 kiloton level. Since SuperHeavy/Starship is about 2.5 times larger than N-1 we can estimate that if it were to explode it might result in an explosion at about the 3 kiloton level, comparable to the Texas City disaster.</span></p><p><span style="font-family: inherit;"> Then outside launch spectators on South Padre Island would be at risk of being hit by flying shrapnel even at the 5 mile distance.</span></p><p><u><b><span style="font-family: inherit;">Shattered Windows.</span></b></u></p><p><span style="font-family: inherit;"> This page gives a summary of the kinds of damage that can result in explosions at the kilotons of TNT level:</span></p><p><a href="https://nuclearsecrecy.com/nukemap/?&kt=9.8&lat=25.9971256&lng=-97.1553612&hob_opt=2&hob_psi=5&hob_ft=98&casualties=1&psi=20,5,1&rem=&therm=_1st-50,_noharm-100,35&cloud=1&zm=13" style="background-color: white; color: #33aaff; font-size: 13.2px;"><span style="font-family: inherit;">https://nuclearsecrecy.com/nukemap/?&kt=9.8&lat=25.9971256&lng=-97.1553612&hob_opt=2&hob_psi=5&hob_ft=98&casualties=1&psi=20,5,1&rem=&therm=_1st-50,_noharm-100,35&cloud=1&zm=13</span></a></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhe5KAe5rNM2MYdFAl10gFvpOEiUb_cLllEx0Y6tbvkFFSf-sAmSpeb3PhSxGM0B5bjlL-q_4bFahJOcASU6K9vWz5_Bfvdib__RFbvi5jH-w-Hjlj_H8E4yaZP2TA3M-7T_nTkwwAs-xvh5OHoSeHSTxBuCfSlnTdtfyjgDABGm2YdcOE4bNKFKi1t/s640/kilotons.png" style="margin-left: 1em; margin-right: 1em;"><span style="font-family: inherit;"><img border="0" data-original-height="480" data-original-width="640" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhe5KAe5rNM2MYdFAl10gFvpOEiUb_cLllEx0Y6tbvkFFSf-sAmSpeb3PhSxGM0B5bjlL-q_4bFahJOcASU6K9vWz5_Bfvdib__RFbvi5jH-w-Hjlj_H8E4yaZP2TA3M-7T_nTkwwAs-xvh5OHoSeHSTxBuCfSlnTdtfyjgDABGm2YdcOE4bNKFKi1t/w640-h480/kilotons.png" width="640" /></span></a></div><span style="font-family: inherit;"><br /></span><p><span style="font-family: inherit;"> It estimates the area of shattered windows by how far away a 1 psi overpressure would reach. However, the page actually underestimates the extent of the shattered windows: while 1 psi is a nice round number to work with, even at some fraction of a psi some proportion of windows would still be shattered.</span></p><p><span style="font-family: inherit;"> Half the windows in the Texas City disaster for instance shattered in Galveston at 10 miles away, a distance farther away than would be predicted by the 1 psi overpressure criterion.</span></p><p><span style="font-family: inherit;"> Note also that large plate glass windows such as those common in store fronts, commercial buildings, and hotel rooms are easier to shatter than the small windows seen in homes. Then launch watchers in hotel rooms on South Padre Island would be at risk of being injured by shattered windows if SH/SS were to explode.</span></p><p><span style="font-family: inherit;"> A greater distance of shattered windows than expected also happened for example in the Soviet N-1 rocket explosion:</span></p><p><span style="font-family: inherit;"> <i>The aftermath</i></span></p><p><i><span style="font-family: inherit;">As the shockwave and the rain of metal debris subsided, Menshikov and his colleagues all emerged out of their shelter stunned but unhurt. Flames were still raging at the launch pad to the northeast under a starry night. The power was shut off around the entire center but five minutes later most facilities started getting their lights back on. (704)</span></i></p><p><i><span style="font-family: inherit;">Top officials were allowed to leave their launch control bunker around 3.5 kilometers from the pad only half an hour after the explosion. When they came up to the surface, a drizzle of unburned kerosene droplets was still coming down to the ground. As was later estimated, as much as 85 percent of the propellant onboard the rocket did not detonate, reducing the force of the blast from a potential 400 tons to just 4.5 - 5 tons. (233) Also fortunately, evacuation measures proved to be effective, as all reports from various sites included "no fatalities." (685) However due to paranoid secrecy, security services apparently intentionally disconnected still operational phone lines between technical facilities and the residential area, leaving numerous family members agonizing for hours over the fate of their loved ones.</span></i></p><p><i><span style="font-family: inherit;">In the meantime, test officers and engineers were streaming back from their shelters to their regular work places. Menshikov and his colleagues found their fueling station in total disarray. Doors and windows were blown off, main gates crooked, equipment thrown all over the floor. Most buildings at Site 113 and surrounding facilities were in similar shape. As dawn came, they were terrified to see numerous dead birds and small animals littering the steppe.</span></i></p><p><i><span style="font-family: inherit;">The heaviest damage was obviously at the epicenter of the explosion. The "Right" pad of the N1 rocket at Site 110 was completely wrecked. One of the 180-meter lightning towers collapsed and was twisted into a spiral. (705) Some pieces from the rocket were found as far as 10 kilometers away and a 400-kilogram gas reservoir landed on the roof of the assembly building at Site 112, four kilometers from the pad.</span></i></p><p><i><span style="font-family: inherit;">Windows were blown off in buildings at Site 2, located six kilometers from the launch pad and as far as 40 kilometers away. A main display window at the Luna cafe in the main residential area at Site 10, some 35 kilometers from the epicenter, was shattered.</span></i></p><p><a href="https://web.archive.org/web/20160410133324/http://russianspaceweb.com/n1_5l.html"><span style="font-family: inherit;">https://web.archive.org/web/20160410133324/http://russianspaceweb.com/n1_5l.html</span></a></p><div style="border: 0px; font-size: 16px; font-stretch: inherit; font-variant-east-asian: inherit; font-variant-numeric: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;"><span style="font-family: inherit;"><span color="inherit" style="border: 0px; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;"> </span><span color="inherit" style="border: 0px; font-size: inherit; font-stretch: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;"> The terrible force of the explosion can be better appreciated by watching a video of it though:</span></span></div><div style="border: 0px; font-size: 16px; font-stretch: inherit; font-variant-east-asian: inherit; font-variant-numeric: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;"><span style="font-family: inherit;"><br aria-hidden="true" /></span></div><div style="border: 0px; font-size: 16px; font-stretch: inherit; font-variant-east-asian: inherit; font-variant-numeric: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;"><span style="font-family: inherit;">The Largest Rocket Explosion Ever - The Soviet N1 Moon Rocket Failure.<br aria-hidden="true" /></span><div class="separator" style="clear: both; text-align: center;"><span style="font-family: inherit;"><iframe allowfullscreen="" class="BLOG_video_class" height="266" src="https://www.youtube.com/embed/gklVhRzkVqA" width="320" youtube-src-id="gklVhRzkVqA"></iframe></span></div><span style="font-family: inherit;"><br /></span></div><div style="border: 0px; font-size: 16px; font-stretch: inherit; font-variant-east-asian: inherit; font-variant-numeric: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;"><span style="font-family: inherit;"><br /></span></div><div style="border: 0px; font-size: 16px; font-stretch: inherit; font-variant-east-asian: inherit; font-variant-numeric: inherit; line-height: inherit; margin: 0px; padding: 0px; vertical-align: baseline;"><span style="font-family: inherit;"><span> Now keep in mind the Superheavy/Starship would have </span><span style="font-size: medium;"><span>2½</span></span><span> times or more the force of this explosion if it did explode.</span><span> </span></span></div><p><span style="font-family: inherit;"> Then when estimating the distance to which shattered windows are to be expected a statistical evaluation must be given for the proportion of shattered windows by distance. This defense department report provides the numbers for a 50% chance of shattering:</span></p><span style="font-family: inherit;">GLASS FRAGMENT HAZARD FROM WINDOWS BROKEN BY AIRBLAST.<br /><a href="https://apps.dtic.mil/sti/pdfs/ADA105824.pdf">https://apps.dtic.mil/sti/pdfs/ADA105824.pdf</a></span><div><span style="font-family: inherit;"><br /></span></div><div><span style="font-family: inherit;"> The numbers in the report given in terms of kilopascals, kPa, where 1 kPa = 0.145 psi., show that depending on the size of the window it can shatter at overpressures down to 0.6 kPa, ~0.1 psi, well less 1 psi:</span></div><div><span style="font-family: inherit;"><br /></span></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgk1JS98RXhyR9sytLqHtGsy644GYhJRNQghIIVG9hat5nqZKDdbKuvR1yvO2CI_uVo-25CS4SctqhR3wJVQANBqkVjdMUI25HAZkh10xU9Dm5jfp-Zn1JEFlsx5Gib4oDryUe9u9WB76vJnitOeqD0iZDtjJSqFgmD89oU4vjmzsqhC7VyHYIcZ7tN/s671/Overpressure%20text.JPG" style="margin-left: 1em; margin-right: 1em;"><span style="font-family: inherit;"><img border="0" data-original-height="671" data-original-width="576" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgk1JS98RXhyR9sytLqHtGsy644GYhJRNQghIIVG9hat5nqZKDdbKuvR1yvO2CI_uVo-25CS4SctqhR3wJVQANBqkVjdMUI25HAZkh10xU9Dm5jfp-Zn1JEFlsx5Gib4oDryUe9u9WB76vJnitOeqD0iZDtjJSqFgmD89oU4vjmzsqhC7VyHYIcZ7tN/s16000/Overpressure%20text.JPG" /></span></a></div><span style="font-family: inherit;"><br /></span><div class="separator" style="clear: both; text-align: center;"><span style="font-family: inherit;"><br /></span></div><div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh-8hCPkgpQ5QdMAjZUJxi-Barip9ClgCcB4XCOGKyDitdhzOWHhla5NTmVb5SkeKk6lXo1XqpRbbgfhdrWtyy__qUuPkJHxADbs7U7rIO3Z5WtXvGyPZAOKvNNOo3_RkMcMsePIJSNX8Vc1vCoiQ5yOi-hiqtfnmVnBqH5poTso0wIirBTxXaGYDKz/s678/Overpressures.JPG" style="margin-left: 1em; margin-right: 1em;"><span style="font-family: inherit;"><img border="0" data-original-height="678" data-original-width="588" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh-8hCPkgpQ5QdMAjZUJxi-Barip9ClgCcB4XCOGKyDitdhzOWHhla5NTmVb5SkeKk6lXo1XqpRbbgfhdrWtyy__qUuPkJHxADbs7U7rIO3Z5WtXvGyPZAOKvNNOo3_RkMcMsePIJSNX8Vc1vCoiQ5yOi-hiqtfnmVnBqH5poTso0wIirBTxXaGYDKz/s16000/Overpressures.JPG" /></span></a></div><span style="font-family: inherit;"><br /></span><p><u><b><span style="font-family: inherit;">Flying Shrapnel.</span></b></u></p><p><span style="font-family: inherit;"> As with shattered windows the distance shrapnel can be propelled has to be given statistically rather than as single set number. This article discusses the range of distance shrapnel can travel depending on energy content of the explosion:</span></p><span style="font-family: inherit;">April 2019<br />COLUMNS<br />Engineering Case Histories: Case 106: Delayed fireball type explosions.<br />When a vessel containing a flammable liquid under pressure (such as those in an LNG road tanker truck) ruptures and ignites, a vapor fireball explosion can occur.</span><p><span style="font-family: inherit;">Sofronas, A., Consulting Engineer</span></p><i><span style="font-family: inherit;">How far away is a safe distance? Flying fragments from pressure effects may not have a reasonable safe distance. Some sources2 mention that 80% of the debris lands within 4 × Rmax and, in rare instances, up to 30 × Rmax (where Rmax is the calculated fireball’s maximum radius). </span></i></div><div><i><span style="font-family: inherit;"><br /></span></i></div><div><i><span style="font-family: inherit;">...</span></i></div><div><i><span style="font-family: inherit;"><br /></span></i></div><div><p style="background-color: white; box-sizing: border-box; color: #333333; margin-bottom: 20px !important; margin-left: 0px; margin-right: 0px; margin-top: 0px; margin: 0px 0px 20px;"><span style="font-family: inherit;"><i>Consider that an LNG tanker truck with a load of <span style="box-sizing: border-box;">M</span> = 19,000 kg (10,000 gal) of propane overturns, a fire erupts and the tanker explodes into a fireball after 10 min of being engulfed in a fire. The heat of combustion (<span style="box-sizing: border-box;">H<span style="bottom: -0.25em; box-sizing: border-box; line-height: 0; position: relative; vertical-align: baseline;">c</span></span>) for propane is 50,000 kJ/kg.</i></span></p><p style="background-color: white; box-sizing: border-box; color: #333333; margin-bottom: 20px !important; margin-left: 0px; margin-right: 0px; margin-top: 0px; margin: 0px 0px 20px;"><span style="font-family: inherit;"><i>From experimental data, the fireball duration, t, can be approximately calculated as shown in Eq. 1:</i></span></p><p style="background-color: white; box-sizing: border-box; color: #333333; margin-bottom: 20px !important; margin-left: 0px; margin-right: 0px; margin-top: 0px; margin: 0px 0px 20px; padding-left: 30px;"><span style="font-family: inherit;"><i><span style="box-sizing: border-box;">t</span> = 0.45 × (<span style="box-sizing: border-box;">M</span>)<span style="box-sizing: border-box; line-height: 0; position: relative; top: -0.5em; vertical-align: baseline;">1/3</span> = 12 sec<span class="Apple-tab-span" style="box-sizing: border-box;"> </span>(1)</i></span></p><p style="background-color: white; box-sizing: border-box; color: #333333; margin-bottom: 20px !important; margin-left: 0px; margin-right: 0px; margin-top: 0px; margin: 0px 0px 20px;"><span style="font-family: inherit;"><i>At the end of the fireball growth period, <span style="box-sizing: border-box;">t,</span> it achieves its maximum radius (Eq. 2):</i></span></p><p style="background-color: white; box-sizing: border-box; color: #333333; margin-bottom: 20px !important; margin-left: 0px; margin-right: 0px; margin-top: 0px; margin: 0px 0px 20px; padding-left: 30px;"><span style="font-family: inherit;"><i><span style="box-sizing: border-box;">R<span style="bottom: -0.25em; box-sizing: border-box; line-height: 0; position: relative; vertical-align: baseline;">max</span></span><span style="bottom: -0.25em; box-sizing: border-box; line-height: 0; position: relative; vertical-align: baseline;"> </span>= 2.9 × (<span style="box-sizing: border-box;">M</span>)<span style="box-sizing: border-box; line-height: 0; position: relative; top: -0.5em; vertical-align: baseline;">1/3</span> = 2.9 × (19,000 kg)<span style="box-sizing: border-box; line-height: 0; position: relative; top: -0.5em; vertical-align: baseline;">1/3</span> = 77.4 m<span class="Apple-tab-span" style="box-sizing: border-box;"> </span>(2)</i></span></p></div><div><div class="separator" style="clear: both; text-align: center;"><a href="https://www.hydrocarbonprocessing.com/media/9330/ech-table-02.jpg" style="margin-left: 1em; margin-right: 1em;"><span style="font-family: inherit;"><img border="0" data-original-height="506" data-original-width="800" height="506" src="https://www.hydrocarbonprocessing.com/media/9330/ech-table-02.jpg" width="800" /></span></a></div><span style="font-family: inherit;"><br /><a href="https://www.hydrocarbonprocessing.com/magazine/2019/april-2019/columns/engineering-case-histories-case-106-delayed-fireball-type-explosions">https://www.hydrocarbonprocessing.com/magazine/2019/april-2019/columns/engineering-case-histories-case-106-delayed-fireball-type-explosions</a></span></div><div><span style="font-family: inherit;"><br /></span></div><div><span style="font-family: inherit;"> Using the equation (2), for a 1,000,000 kg total methane fuel load for SuperHeavy/Starship, that would be a fireball radius of 290 m. Then if some proportion of the fragments can be sent 30 times the fireball radius, for SH/SS that would be 8,700 m, 8.7 km away.</span></div><div><span style="font-family: inherit;"><br /></span></div><div><span style="font-family: inherit;"> That would be for relatively small proportion of the fragments though. A statistical examination has to be done to see the proportion of the fragments that could reach say 5 km. </span></div><div><span style="font-family: inherit;"><br /></span></div><div><span style="font-family: inherit;"> Even if the proportion of fragments that can reach beyond the 5 km exclusion zone is small, it must be kept in mind many residents and visitors in Port Isabel and South Padre Island will be outside to watch the launch, increasing the chance someone could be hit by the fragments.</span></div><div><span style="font-family: inherit;"><br /></span></div><div><span style="font-family: inherit;"> Note also, the Mexican border is inside the 5 km exclusion zone. Then Mexican citizens on the other side of the border also run the risk of being hit by flying shrapnel if there is an explosion. In such a case, SpaceX would run the risk of causing an international incident.</span></div><div><span style="font-family: inherit;"><br /></span></div><div><span style="font-family: inherit;"> <u><b>Alternative Proposals.</b></u></span></div><div><u><b><span style="font-family: inherit;"><br /></span></b></u></div><div><span style="font-family: inherit;"> SpaceX does not have to launch Superheavy/Starship from the Boca Chica launch site. Note that the original proposal by<a href="https://futurism.com/the-byte/elon-musk-starship-spaceports-offshore" target="_blank"> SpaceX for passenger flights was from a platform 20 miles off shore because of noise levels from a launch</a>. This can still be done. The launch tower would have to be made mobile. This is doable of course as the Saturn V, Space Shuttle, and SLS mobile launch towers showed. The Starship launch tower would have to be carried to the coast, lifted onto a barge, then transported to a location sufficiently distant off-shore.</span></div><div><span style="font-family: inherit;"><br /></span></div><div><span style="font-family: inherit;">Another possibility would not to use a Superheavy at all. SpaceX could take a clue from the Falcon Heavy development which actually costs 1/4th to 1/6th that of entire new rocket built from scratch. SpaceX would first build a smaller two-stage with the Starship now as the first stage and a smaller mini-Starship, if you will, as the upper stage. Such a rocket could get ca. 100 tons to LEO. After many successful launches of this vehicle, Space would then proceed to a triple-core version, a la the Falcon Heavy. Such a triple-core vehicle would be able to match the 300 tons to LEO of the SuperHeavy/Starship. Note that, prior to the Falcon Heavy launch, SpaceX had launched over 1,000 Merlin engines on actual orbital flights. Such an approach would similarly result in high reliability of the Raptor engine before extending to a triple-core version. But as it is now SpaceX proposes to build the biggest rocket ever made with engines that have made zero actual flights to space.</span></div><div><span style="font-family: inherit;"><br /></span></div><div><span style="font-family: inherit;"> Note that this smaller two-stage vehicle could do both manned lunar and Mars missions in a single launch, rather than 8 to 16 refueling flights needed for the SuperHeavy/Starship approach. When SpaceX wanted the high cargo triple-core version that then would be launched off-shore. It will almost certainly be the case the single core Starship would launch far more times than the triple-core version, just like is the case with the Falcon 9 compared to the Falcon Heavy.</span></div><div><span style="font-family: inherit;"><br /></span></div><div><span style="font-family: inherit;"> See discussion here:</span></div><div><span style="font-family: inherit;"><br /></span></div><div><span style="font-family: inherit;">The Missed Lesson of the Falcon Heavy.</span></div><div><span><a href="https://exoscientist.blogspot.com/2023/02/the-missed-lesson-of-falcon-heavy.html">https://exoscientist.blogspot.com/2023/02/the-missed-lesson-of-falcon-heavy.html</a></span></div><div><span style="font-family: inherit;"><br /></span></div><div><span style="font-family: inherit;"> Robert Clark</span></div><div><span style="font-family: inherit;"> </span></div><div><br /></div>Robert Clarkhttp://www.blogger.com/profile/16114043697010364282noreply@blogger.com2