Thursday, June 21, 2012

Low Cost HLV, page 3: Lightweighting the S-IC Stage.

Copyright 2012 Robert Clark

                                                    SASSTO - Saturn-derived SSTO Launch Vehicle 
                                                    Credit: © Mark Wade

 I showed in the post Low Cost HLV, page 2: Comparison to the S-IC Stage that the S-IC first stage of the Saturn V could give a nearly 20-to-1 mass ratio using a lighter thrust structure and using four RD-171 engines instead of five F-1 engines. But in fact we can do better than this. The S-IC of the 1960's did not have available the aluminum-lithium alloy used for example on the Falcon 9 and shuttle ET. Here I calculate a lighter structure using this lighter alloy and some mass reducing structural changes.

 The tank mass of the S-IC stage and of some other rocket stages is discussed in this key report:

Single Stage To Orbit Mass Budgets Derived From Propellant Density and Specific Impulse.
John C. Whitehead
32nd AIAA/ASME/SAE/ASEE Joint Propulsion ConferenceLake Buena Vista, FLJuly 1-3, 1996

 On page 8 in Fig. 6 is given a comparison of the tank weights of the Saturn S-IC, Atlas II, and shuttle ET:

 We've already reduced the mass of the stage down to 113,000 kg by using a lighter thrust structure in the prior post. Fins are not really needed for large rockets with computer guidance and control, so remove these to reduce the mass again to 112,000 kg. The  four 4 meter diameter RD-171 engines can fit under the 10 meter diameter S-IC tank, so remove the engine fairings to bring the mass down to 108,000 kg.
 Now use common bulkhead design to reduce the tank mass further. The question of using common bulkhead design for the S-IC arose during the Apollo design period:

SP-4206 Stages to Saturn.
7. The Lower Stages: S-IC and S-II.
The main configuration of the S-IC had already been established by MSFC, including the decision to use RP-1, as opposed to the LH2 fuel used in the upper stages. Although LH2 promised greater power, some quick figuring indicated that it would not work for the first stage booster.Liquid hydrogen was only one half as dense as kerosene. This density ratio indicated that, for the necessary propellant, an LH2 tank design would require a far larger tank volume than required for RP-1. The size would create unacceptable penalties in tank weight and aerodynamic design. So, RP-1 became the fuel. In addition, because both the fuel and oxidant were relatively dense, engineers chose a separate, rather than integral, container configuration with a common bulkhead. The leading issue prior to the contract awards related to the number of engines the first stage would mount.

   This could be interpreted to mean the density of the propellant made it unfeasible, but I think the relatively smaller tankage mass using the dense propellants made the more difficult common bulkhead design unnecessary. For instance as you see in that Fig. 6 from Whitehead's report, in the shuttle ET tank the intertank weighs more than the entire oxygen tank. The relative weight of the intertank is not as bad for the kerosene S-IC. Still, common bulkhead design is used for the large kerosene first stage on the Falcon 9 to help save weight.

 So to minimize stage weight we will remove the interstage and one of the bulkheads. Assuming top and bottom bulkheads weigh the same for each of the LOX and kerosene tanks on the S-IC, then from the information in Fig. 6, the LOX bulkheads weigh 4 mT each and the kerosene, 3.3 mT. Conservatively, let's say we remove one of the kerosene bulkheads instead of a LOX bulkhead since we may need the larger LOX bulkhead for strength. Then also removing the 6 mT intertank, we bring the dry mass down to 99 mT.

 Now estimate the weight saving using the lighter aluminum-lithium alloy. From the Wikipedia page on the shuttle ET, the tank weight reduced from 35,000 kg using aluminum alloy 2219, the same alloy used for the S-IC tanks, to 26,500 kg using aluminum-lithium alloy, a reduction of 24%.

 After the structural changes, the tanks now weigh 25.5 mT. Subtracting off 24% from this is a reduction in mass by 6 mT. This brings the stage mass down to 93 mT.

 Keep in mind though, the plan is to use a shuttle ET size tank to save cost on tooling. The ca. 720 mT hydrolox of the shuttle ET becomes ca. 2,100 mT with the 3 times denser kerolox. This turns out to be about the same kerolox carried by the S-IC. So the purpose here was just to get an idea of a lightweight stage you can get using modern materials.

 Now notice you get significant payload as a SSTO using the RD-171 engines at 338 s vacuum Isp. Taking the required delta-v to orbit as 9,150 m/s for kerolox, you can get 48 mT to orbit:

338*9.81ln(1 + 2,100/(93 + 48)) = 9,170 m/s.

 Note though that if we are to use the shuttle ET as a stage then the pointed end of the LOX tank would need to be removed. We could take the equivalent cylindrical LOX tank of the same volume. It would have the same dry weight, so the stage dry mass stays the same.

 However, if you take the full length of a cylindrical tank now as 46.9 m and the diameter as 8.4 m, per the specifications of the SLWT version of the ET, and the density of kerolox as about 1,030 kg/m^3, then we get about 2,600 mT kerolox. The tank weight would increase somewhat without the pointed end, but not by much compared to the entire stage weight. Then you could loft 82 mT to orbit:

338*9.81ln(1 + 2,600/(93 + 82)) = 9,160 m/s.

 A propellant load of 2,600 mT at dry mass of 93 mT corresponds to a mass ratio close to 29 to 1, rather high. But SpaceX has said with their side boosters on the Falcon Heavy they expect to achieve a mass ratio of 30 to 1, and mass ratio does get better as you scale up a stage,with this shuttle ET size stage being much larger.

 This payload of 82 mT is better than the 70 mT to be carried by the interim SLS. Remember our HLV is to be developed using the SpaceX-style commercial approach. Then based on a $2,000/kg price of the Falcon Heavy, the full two stage version of our HLV as comparably priced might only cost ca. $200 million per launch at a 100 mT payload to orbit.

 So the SSTO version would even cost less than this, perhaps only ca. $100 million per launch for the 82 mT payload to orbit.

 The dry weight could be lightened further by using composites. Estimates put the weight savings in the structural mass in the 40% range for a fully composite structure. In that case the payload could exceed 100 mT for this SSTO.

 An increase of the Isp could be possible by using an aerospike or plug nozzle, up to the range of 360 s. The multi-nozzle format of the RD-171 engines makes this feasible. The four nozzles of each engine would be shortened and arranged around a central aerospike. This was the idea behind the aerospikes planned for the X-33 and VentureStar. It was also used earlier in the planned Beta SSTO of Dietrich Koelle and the SASSTO SSTO of Phillip Bono.

 An argument against this was that the aerospike nozzle would make the propulsion system too heavy. For instance for the aerospike on the X-33 the thrust/weight ratio was only 40 to 1, compared to a 70 to 1 ratio for the SSME's for example. However, the lightweight, high temperature ceramics and composites available now should make the T/W comparable to bell nozzle engines:

Ceramic Materials for Reusable Liquid Fueled Rocket Engine Combustion Devices.

  Bob Clark

Note: The SASSTO SSTO shown at the top and discussed near the end was derived from the Saturn S-IVB stage, not the S-IC, and was hydrogen fueled. The Beta SSTO discussed was also hydrogen fueled. However, a key result of the cited report of John C. Whitehead is that it is actually easier to make a kerosene-fueled SSTO. This is because the large and heavy hydrogen fuel tanks swamps out the advantage of its higher Isp.  - B.C., 6/22/2012.

Sunday, June 17, 2012

Low cost development and applications of the new NRO donated telescopes, Page 4.

Copyright 2012 Robert Clark 

 A key reason why these space telescopes developed under a more commercial approach can be done much more cheaply is the more expensive "space qualified" electronics have been found to be unnecessary. This is described by Dr. John Hunter in regards to G-hardening the electronics:

Propellant Delivery to Orbit in Support of Mars Exploration
 with Hydrogen Gas Guns - Dr. John Hunter.

 About 14 minutes in Hunter discusses standard off the shelf components can be used with inexpensive modifications even in regards to gas gun launch at hundreds of g's. As an example he notes cell phones have to be designed to survive such high g's just from being dropped from normal height.

 Radiation resistance can also be done with off the shelf electronics with inexpensive modifications. This is argued by Dennis Wingo whose area of expertise is developing electronics for space use:

Bootstrapping the Moon.
By Dennis Wingo Posted Wednesday, May 7, 2008
Ideas to Lower the Cost of the Effort
The first thing to attack is the military industrial complex focus on radiation tolerance for integrated circuits. This one thing has driven the cost of space projects higher and higher as designers have to use several generations old microprocessors, and all types of integrated circuits. This is because there are specifications that individual chips have to meet for latch up and single event upsets. Since most off the shelf (COTS) chips are not particularly radiation hardened, this means that for hardware that goes through the radiation belts or is used in environments where radiation might be a problem that you have to modify existing chip designs to harden them.
This is enormously expensive and the market for these chips is very small in comparison to the commercial market so the number of advanced chips flying is actually very small and the tendency is that the current generation of space qualified chips are several generations behind their commercial brethren with the gap growing year by year. This is why the International Space Station is controlled by 80386 25 Mhz microprocessors that were obsolete in the commercial world in 1992. What it also means is that the tools for software development are ether generations behind as well or are very poorly designed as it is much more expensive for these systems with a very limited market and installed base.
This has been the case since the early 1990's as the amateur radio satellites proved when they basically completely abandoned the concept of space qualified and successfully flew advanced chips. They were able to do this via the concept of shielding the chips with tantalum or other chip and box level shielding techniques. It costs a little weight but with the advances in chip technology, software, and software systems, the total systems costs can be dramatically lowered.
An example of one government organization that understood this was the Strategic Defense Initiative Organization's Clementine mission in 1993 that flew commercial state of the art processors and dynamic RAM memory for the imaging system. It worked fine but the military spec RAD 3000 had a software glitch that opened up a thruster and ended the mission before they could go to an asteroid after successfully operating in lunar orbit for several months. More recent software errors have reportedly crippled much more expensive spacecraft. Today with software growing to as much as 1/3 of the total cost of an advanced spacecraft major savings can be accomplished and schedules compressed by using this approach. So that iPhone that you love may be your communicator on the Moon! The European Space Agency was able last year to get NASA to agree to using the advanced technology of Wi-Fi and the Internet protocol for the lunar outpost. This was a celebrated victory.

 So off the shelf electronic components can be used with just a little extra weight for shielding.

 This has majorly important results if you already have the space qualified optical components and support structure. It means the space based scopes can then be completed for little more than for the ground versions. 

 This report shows those ground scope costs are surprisingly low compared to the prices now charged for comparable space telescopes:

The Scaling Relationship Between Telescope Cost and Aperture Size for Very Large Telescopes.
Gerard T. van Belle
Michelson Science Center, California Institute of Technology, Pasadena, CA 91125
Aden Baker Meinel & Marjorie Pettit Meinel
Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109

 You see the ground scopes in the 2 to 3 meter diameter range are in the $10 to $20 million range and even less. 

This supports the claim of PRI that a commercial approach to the telescope construction can cut costs by one to two orders of magnitude.

  Bob Clark

Friday, June 15, 2012

On the lasting importance of the SpaceX accomplishment, Page 2.

Copyright 2012 Robert Clark 

Nice video here with Alan Lindenmoyer, NASA's head of the commercial crew program:

America's New Paths in Space.

 At about the 6:17 point in the video, Lindenmoyer makes the key point that it's part of NASA's charter to stimulate the commercial space industry in America. Then efforts by some in government to limit NASA's support of the commercial crew program are disregarding a key component of why NASA exists in the first place.

 Supporters of commercial space access have long argued that aerospace companies could create a privately developed launcher at costs in the range they spend to produce new jet airliners at a few billion dollars. See this argument for example in Harry G. Stine's Halfway to Anywhere: Achieving America's Destiny In Space.

The problem is there is a much larger market for airline travel than for space travel to pay for those large up front development costs. However, a key result of the success of SpaceX in privately developing a launcher and capsule is that they were able to develop them while cutting 90% off the usual cost estimates for the development of such vehicles. Then following their cost cutting model, instead of the usual estimate of a few billion dollars to develop a launcher it would only cost in the few hundred million dollars range.

 This means there is a market that the usual large aerospace companies and even the smaller new ones such as SpaceX, Orbital Sciences, Sierra Nevada,  Blue Origin, etc. would have in order to pay back this much reduced initial investment. Such a market is the same as that for jet airliners, private, commercial passengers.
 Peter Diamandis makes this point in this effective TED lecture where he refers to this market as "self-loading carbon payloads":

Peter Diamandis: Taking the next giant leap in space.

  A well researched example of such a manned vehicle would be the fully orbital, fully reusable DC-Y follow-on to the DC-X. It was estimated to have a $5 billion development cost which would include 4 flight vehicles. However, the important point is as privately developed, that could be reduced to perhaps $500 million to get a fully reusable, manned launcher.

   Bob Clark

Wednesday, June 13, 2012

Low cost development and applications of the new NRO donated telescopes, Page 3.

Copyright 2012 Robert Clark

Credit: NASA/JPL-Caltech/UCLA. This is a mosaic of the images covering the entire sky as observed by the Wide-field Infrared Survey Explorer (WISE), part of its All-Sky Data Release.  

 The WISE mission has released all the images taken during the duration of the mission:

NASA Releases New WISE Mission Catalog of Entire Infrared Sky.

"Today, WISE delivers the fruit of 14 years of effort to the astronomical community," said Edward Wright, WISE principal investigator at UCLA, who first began working on the mission with other team members in 1998.
WISE launched Dec. 14, 2009, and mapped the entire sky in 2010 with vastly better sensitivity than its predecessors. It collected more than 2.7 million images taken at four infrared wavelengths of light, capturing everything from nearby asteroids to distant galaxies. Since then, the team has been processing more than 15 trillion bytes of returned data. A preliminary release of WISE data, covering the first half of the sky surveyed, was made last April.
The WISE catalog of the entire sky meets the mission's fundamental objective. The individual WISE exposures have been combined into an atlas of more than 18,000 images covering the sky and a catalog listing the infrared properties of more than 560 million individual objects found in the images. Most of the objects are stars and galaxies, with roughly equal numbers of each. Many of them have never been seen before.

WISE Delivers Millions of Galaxies, Stars, Asteroids.
Astronomers across the globe can now sift through hundreds of millions of galaxies, stars and asteroids collected in the first bundle of data from NASA's Wide-field Infrared Survey Explorer (WISE) mission.
"Starting today thousands of new eyes will be looking at WISE data, and I expect many surprises," said Edward (Ned) Wright of UCLA, the mission's principal investigator. 

The Wide-field Infrared Survey Explorer
All-Sky Data Release
March 14, 2012

 The WISE mission has made many important discoveries: 

WISE Finds Few Brown Dwarfs Close to Home.
June 08, 2012
WISE was launched in 2009 and surveyed the entire sky in infrared light in 2010. One of the mission's main science goals was to survey the sky for the elusive brown dwarfs. These small bodies start their lives like stars, but lack the bulk required to burn nuclear fuel. With time, they cool and fade, making them difficult to find. 
Improvements in WISE's infrared vision over past missions have allowed it to pick up the faint glow of many of these hidden objects. In August 2011, the mission announced the discovery of the coolest brown dwarfs spotted yet, a new class of stars called Y dwarfs. One of the Y dwarfs is less than 80 degrees Fahrenheit (25 degrees Celsius), or about room temperature, making it the coldest star-like body known. Since then, the WISE science team has surveyed the entire landscape around our sun and discovered 200 brown dwarfs, including 13 Y dwarfs. 

NASA Survey Counts Potentially Hazardous Asteroids.
May 16, 2012
PASADENA, Calif. -- Observations from NASA's Wide-field Infrared Survey Explorer (WISE) have led to the best assessment yet of our solar system's population of potentially hazardous asteroids. The results reveal new information about their total numbers, origins and the possible dangers they may pose.
Potentially hazardous asteroids, or PHAs, are a subset of the larger group of near-Earth asteroids. The PHAs have the closest orbits to Earth's, coming within five million miles (about eight million kilometers), and they are big enough to survive passing through Earth's atmosphere and cause damage on a regional, or greater, scale.
The new results come from the asteroid-hunting portion of the WISE mission, called NEOWISE. The project sampled 107 PHAs to make predictions about the entire population as a whole. Findings indicate there are roughly 4,700 PHAs, plus or minus 1,500, with diameters larger than 330 feet (about 100 meters). So far, an estimated 20 to 30 percent of these objects have been found.
While previous estimates of PHAs predicted similar numbers, they were rough approximations. NEOWISE has generated a more credible estimate of the objects' total numbers and sizes.
"The NEOWISE analysis shows us we've made a good start at finding those objects that truly represent an impact hazard to Earth," said Lindley Johnson, program executive for the Near-Earth Object Observation Program at NASA Headquarters in Washington. "But we've many more to find, and it will take a concerted effort during the next couple of decades to find all of them that could do serious damage or be a mission destination in the future."

in addition to the searches for nomad planets and hypothesized planets at the edge of the Solar System: 

Can WISE Find the Hypothetical 'Tyche'?
February 18, 2011
Frequently Asked Questions
Q: When could data from WISE confirm or rule out the existence of the hypothesized planet Tyche?
A: It is too early to know whether WISE data confirms or rules out a large object in the Oort cloud. Analysis over the next couple of years will be needed to determine if WISE has actually detected such a world or not. The first 14 weeks of data, being released in April 2011, are unlikely to be sufficient. The full survey, scheduled for release in March 2012, should provide greater insight. Once the WISE data are fully processed, released and analyzed, the Tyche hypothesis that Matese and Whitmire propose will be tested.

  With the release of the image database, to help with the search for brown drawfs, potentially harmful asteroids, nomad planets, and extreme Solar System planets I recommend the use of distributed computing such as that used for the Seti@Home project to allow potentially millions of people to take part in the searches. With the great interest in the public in extraterrestrial life and possible Earth impacting asteroids, and with the possibility of discovering a new Solar System planet, there very likely would be a great deal of interest in such a project.

 And with asteroid mining ventures needing to find high value asteroids nearby, they could offer prizes, i.e., rewards, for those users who happened to find them.

  Bob Clark

Tuesday, June 12, 2012

Low cost development and applications of the new NRO donated telescopes, Page 2.

Copyright 2012 Robert Clark 
Credit: NASA simulated image of extreme Solar System bodies

Hubble-class scopes can be placed at GEO rather than a Lagrangian point.

The Planetary Resources, Inc. version of such an infrared scope would operate in low Earth orbit. Then it quite likely could be launched by a Falcon 9, at a ca. $50 million launch cost. However, the plans for the Wide Field Infrared Survey Telescope (WFIRST) that these NRO scopes could be used for would be to place it at a Sun-Earth Lagrangian point millions of miles away. But according to this article the large size of these new scopes would allow them to be placed much nearer, in geosynchronous orbit:

Ex-Spy Telescope May Get New Identity as a Space Investigator.
Published: June 4, 2012

The telescope’s short length means its camera could have the wide field of view necessary to inspect large areas of the sky for supernovae.
Even bigger advantages come, astronomers say, from the fact that the telescope’s diameter, 94 inches, is twice as big as that contemplated for Wfirst, giving it four times the light-gathering power, from which a whole host of savings cascade.
Instead of requiring an expensive launch to a solar orbit, the telescope can operate in geosynchronous Earth orbit, complete its survey of the sky four times faster, and download data to the Earth faster.
Equipped with a coronagraph, which blocks light from the sun’s disk to look for exoplanets, another of Wfirst’s goals, the former spy telescope could see planets down to the size of Jupiter around other stars.

 Then they could be launched at least by a Falcon Heavy at a $100 million launch cost. The colder temperatures out at GEO compared to LEO would make the PRI asteroid search more sensitive also.

Cost advantage of a single large scope compared to multiple small scopes.

 In regards to PRI financing the development of such a scope, PRI has announced plans to make small telescopes of about 9" diameter to be sold for Earth imaging purposes and to combine hundreds to thousands of these for the asteroid search:

APRIL 26, 2012
Planetary Resources could take megapixel images of exoplanet and makes billions by 2020 before mining anything.

However, linking up optical or infrared telescopes in orbit to form a single coherent image has not been done before and likely will add significantly to the price of the individual scopes. If it does work then the resolution will be as the widest distance between the scopes. However the light collecting area, which is what is needed for the sensitivity of an asteroid search, will only be as the sum of the areas of the scopes.
 The new NRO scopes have 11 times the diameter of the planned PRI telescopes. So it would take 121 of the PRI scopes to make up the sensitivity of a single one of the NRO scopes, assuming they are able to get a single coherent image from the combined scopes. 
 PRI has said they expect to cut the costs of their scopes by 1 to 2 orders of magnitude below that of, for example, a telescope as on the WISE mission. This would make them in the $3 to $30 million dollar range. With the complexity of the wide scale link up of the scopes at hundreds to thousands of kilometer distances,  it seems likely it would be closer to the higher range. Even if the Arkyds amount to $10 million each including launch costs, that would still be over a billion dollars to match the sensitivity of a single one of the NRO  scopes. In that case a single one of the NRO scopes at a few hundred million dollar cost would be advantageous.

The Hubble-class scopes properly instrumented can serve as upgrades both for the WISE and WFIRST scopes. 

 Interesting articles here about the WISE capability to detect large unknown planets at the very fringes of the Solar System:

Up telescope! Search begins for giant new planet.Tyche may be bigger than Jupiter and orbit at the outer edge of thesolar system. BY PAUL RODGERS SUNDAY 13 FEBRUARY 2011

About that Giant Planet Possibly Hiding in the Outer Solar NANCY ATKINSON on FEBRUARY 16, 2011

 The 40 times greater collecting area means the Hubble-class scopes could perform a much more sensitive search than WISE for these extreme Solar System planets.
 Another possible use would be the search for nomad or rogue planets which are planets in the interstellar space between star systems:

Researchers say galaxy may swarm with 'nomad planets'. A good count, especially of the smaller objects, will have towait for the next generation of big survey telescopes, especially thespace-based Wide-Field Infrared Survey Telescope and the ground-based Large Synoptic Survey Telescope, both set to begin operation in theearly 2020s. A confirmation of the estimate could lend credence to another possibility mentioned in the paper - that as nomad planets roam theirstarry pastures, collisions could scatter their microbial flocks to seed life elsewhere. February 23, 2012 BY ANDY FREEBERG

 Again the Hubble-class scopes would have much better sensitivity to detect them than the Wide-Field Infrared Survey Telescope(WFIRST) scope mentioned.
 It has been speculated such nomad planets could have life in subsurface water. Since some of these nomads are believed to be ejected from other star systems, nomads near to us or captured by our Solar System would provide a more near term route to search for life in other star systems.
 Because of the interest in the search for extraterrestrial life, you could have another source for private funding for such scopes. One could have for example the scope named after a foundation or individual who provided a large portion of the funding, like the Keck telescope.

   Bob Clark

Friday, June 8, 2012

Low cost development and applications of the new NRO donated telescopes.

Copyright 2012 Robert Clark

Credit: simulated image of Hubble-class telescope at Mars from NASA images.

NASA gets two military spy telescopes for astronomy. 
By Joel Achenbach, Published: June 4 
The announcement Monday raised the obvious question of why the 
intelligence agency would no longer want, or need, two Hubble-class 
telescopes. A spokeswoman, Loretta DeSio, provided information 
“They no longer possessed intelligence-collection uses,” she said of 
the telescopes. 

The explanation clearly is that Hubble scale telescopes are now 
obsolete for surveillance as I earlier argued, [1].

Asteroid Detection for Planetary Defense and Asteroidal Prospecting.

 A useful application of the new scopes would be detection of asteroids for planetary defense purposes, and for the new asteroid mining ventures. For instance the wide field camera on the WISE mission satellite was able to find this Trojan class asteroid:

NASA's WISE Mission Finds First Trojan Asteroid Sharing Earth's Orbit.
 The mirror on the new scopes is 100 inches compared to 16 inches for the WISE mission satellite, resulting in nearly 40 times greater collecting area and sensitivity.

 In fact, NASA might be able to have the satellite development be partially funded by the asteroid mining ventures. If so, then the development could be done much more cheaply with a commercial approach to their development.

 Indeed Planetary Resources referred to the NASA WISE satellite in stating they could produce comparable telescopes to the WISE at 1 to 2 order of magnitude lower costs:

Billionaire-backed asteroid mining venture starts with space telescopes.
The key factor is the cost: Lewicki noted that an imaging instrument like NASA's Wide-field Infrared Survey Explorer would typically cost hundreds of millions of dollars. "We're looking to go one to two orders of magnitude below that," he said.  [2]

 For a Hubble-class telescope this would be reduced at least to the few hundred million dollar cost range, thus solving the funding problem NASA has for deploying such scopes. That the scopes could indeed be produced at such reduced costs is given credence by the fact that SpaceX was able to cut development costs both for their launchers and their spacecraft by an order of magnitude by following a commercial approach to their development. 

 Note also that Hubble was designed and built in the 1980's, 25 years ago. From Moore's law there have been major reductions in size and cost of electronic components since then, which  further supports the idea the development costs can be done much more cheaply now for the instruments than was the case for Hubble.

 For the launch costs, Hubble was done by the shuttle with a ca. 20 mT payload capacity. So a Hubble-class scope launched just to LEO could be done by any of the current largest launchers with a 20 mT capacity to LEO, at costs in the $200 million range. 

 However, Hubble was just barely above 10 mT in weight, at about 11 mT. Reportedly these new scopes weigh less than Hubble and with the reduction and size and weight in electronics since the time Hubble was developed, these new scopes quite likely could be brought in at 10 mT or less. In that case they could be launched to LEO by a Falcon 9 at a $50 million launch cost.

Mars Imaging Satellites.

 Another useful application of one of the scopes would be for a Mars orbital satellite. Again as developed by Planetary Resources in a commercial approach to the development it could be done for a few hundred million dollars. 

 The mirror on the current highest resolution Mars satellite Mars Reconnaissance Orbiter(MRO) has a 20 inch diameter with a resolution on the Mars surface of 25 centimeters, about 10 inches. Then the 100 inch diameter on the Hubble class scope would give a resolution of 5 centimeters, about 2 inches. 

 MRO came within 100 km of the surface at periapsis during aerobraking on Mars, [3], while its final orbit was at about 300 km. However, MRO did not do imaging at closest approach during aerobraking. If a Hubble class scope did such imaging, then at 100 km altitude it could get sub-inch resolution at periapsis.

 Mars orbiting satellites typically have both wide field and narrow field cameras, with the wide field cameras giving much courser resolution than the narrow field. However, these new scopes reportedly can give resolution nearly as good as Hubble even with a wide field. 

 This is important because for the Mars orbiters when taking their highest resolution images with the narrow field cameras, the coverage of the surface is quite spotty. However, with these new scopes having wide field capability at high resolution you can get entire surface coverage at high resolution. This would require high data throughput of course which should now be possible with state of art computer storage density and processing speeds.

 For the launch cost, Robert Zubrin suggests the Falcon Heavy could send 14 mT to Mars orbit with a conventional hydrogen-fueled upper stage, say of Centaur-type, [4]. A single one of the current largest Centaurs at 20 mT gross mass probably wouldn't do it though. You would need two, either parallel or serially staged. At a Centaur cost of $30 million, assign $60 million for the cost of the upper stage. Then with a $100 million cost of the Falcon Heavy, the launch cost would probably be under $200 million, when you add on the cost of integrating the Centaurs to the rest of the vehicle.

Speculations on the Next Mars Imaging Satellites after the Hubble-class.

 Because of the ever improving resolution of orbital satellites sent to Mars, I once wrote rather tongue-in-cheek that we will soon be able to resolve Martian microbes from orbit, [5]. However, remarkable new research might imply such astonishing resolution near term might actually come to pass. 

 To get such high resolution from orbit would require an impractically large mirror, one might  think. This is because the diffraction limit of classical electromagnetic wave theory puts limits on the degree of resolution you can get for a given size mirror. However, new research in "negative refractive index" materials shows using quantum mechanics you can get resolution actually beyond the diffraction limit. The result is you can get much better resolution for a given size mirror than previously thought possible, [6], [7].

  Bob Clark


1.)Newsgroups: sci.astro, sci.physics,, sci.astro.amateur, 
From: Robert Clark <> 
Date: 23 Apr 2007 02:49:39 -0700 
Subject: Orbital surveillance satellites now exceed 1 inch resolution. 

2.)Billionaire-backed asteroid mining venture starts with space telescopes.
23 Apr, 2012 11:37pm, EDT

3.)Mars cameras debut as NASA craft adjusts orbit.
Posted: April 13, 2006

4.)The Use of SpaceX Hardware to Accomplish Near-Term Human Mars Mission.

5.)Newsgroups: sci.astro, sci.physics, sci.geo.geology, alt.sci.planetary, sci.astro.amateur
From: "Robert Clark" <>
Date: 10 Jan 2007 09:12:09 -0800
Subject: We will soon be able to resolve Mars microbes from orbit. ;-)

6.)Negative index metamaterials.


Friday, June 1, 2012

On the lasting importance of the SpaceX accomplishment.

Copyright 2012 Robert Clark

Credit: NASA

 SpaceX deserves major kudos in successfully launching the Dragon spacecraft, docking with the ISS, and recovering the capsule on Earth. However, it is important to note there is nothing especial innovative of the SpaceX designs. Their engines are no more efficient than the engines on the original Atlas rocket of the 1960's that first lofted John Glenn to orbit. And their stages use the same lightweighting techniques known since the 1970's. SpaceX has said they don't want to patent their designs because it would give their competitors, such as China, an easy route to copying their designs. But I wonder if the real reason is that they are the same techniques known for decades. Their important innovation is that they used good business practices in privately developing their launchers and spacecraft to cut the development costs by 90%(!)

SpaceX Might Be Able To Teach NASA A Lesson.
May 23, 2011
By Frank Morring, Jr.
“I think one would want to understand in some detail . . . why would it be between four and 10 times more expensive for NASA to do this, especially at a time when one of the issues facing NASA is how to develop the heavy-lift launch vehicle within the budget profile that the committee has given it,” Chyba says.
He cites an analysis contained in NASA’s report to Congress on the market for commercial crew and cargo services to LEO that found it would cost NASA between $1.7 billion and $4 billion to do the same Falcon-9 development that cost SpaceX $390 million. In its analysis, which contained no estimates for the future cost of commercial transportation services to the International Space Station (ISS) beyond those already under contract, NASA says it had “verified” those SpaceX cost figures.
For comparison, agency experts used the NASA-Air Force Cost Model—“a parametric cost-estimating tool with a historical database of over 130 NASA and Air Force spaceflight hardware projects”—to generate estimates of what it would cost the civil space agency to match the SpaceX accomplishment. Using the “traditional NASA approach,” the agency analysts found the cost would be $4 billion. That would drop to $1.7 billion with different assumptions representative of “a more commercial development approach,” NASA says.

SpaceX Might Be Able To Teach NASA A Lesson – Aerospace (

 Space travel can become world-wide once the implications of what SpaceX has done are fully realized: development of a manned spaceflight capability can be accomplished, as privately developed, at a cost of a few hundred million dollars, not the several billion dollars long thought.

 That is an overwhelmingly important fact. It means that all the large aerospace companies in the world can afford to privately develop their own manned launchers and/or spacecraft and expect to make a profit on it. It means nearly every country in the world can afford to have their own manned spaceflight capability.

 Example, here's a British manned spacecraft that was studied in the 1980's:

Multi-Role Recovery Capsule.

British manned spacecraft. Study 1987. Britain was the only European Space Agency member opposed to ESA's ambitious man-in-space plan, and the British conservative government refused to approve the November 1987 plan.
However, the British aerospace industry did propose some interesting alternatives, such as the $2-billion 'Multi-Role Recovery Capsule'.
Multi-Role Recovery Capsule (
 The important fact is SpaceX has shown with its Dragon capsule and NASA has confirmed with its CCDEV program that privately developed spacecraft, perhaps with governmental seed money, can be developed for costs in the few hundred million dollars range. So the BAe could develop this spacecraft, not for $2 billion, but for an amount comparable to that spent on the Dragon, ca. $300 million.

 Likewise, the individual nations of the ESA could develop their own indigenous manned spaceflight capability by following this approach. The result? Manned spaceflight becomes routine world-wide.

 That is the lasting importance of what SpaceX has accomplished.

     Bob Clark

Note: the original version of this post said Alan Shepard was lofted to suborbit on the Atlas. That was actually on the Mercury-Redstone. John Glenn was launched to orbit on the Mercury-Atlas. - B.C.

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