U.S. will lag behind in utilization of resources on the Moon.

 Copyright 2023 Robert Clark

 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. 

 The LCROSS mission provided tantalizing hints of valuable metals from its orbital observations: 

Moon Blast Reveals Lunar Surface Rich With Compounds.
Science Oct 21, 2010 2:05 PM EDT.
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.
https://www.pbs.org/newshour/science/its-confirmed-there-is-water

 And a Japanese lunar orbiter gave indications of uranium: 

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.
By Julian Ryall in Tokyo 4:58PM BST 01 Jul 2009.
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.
The discovery opens up the possibility of mining operations on a commercial basis or even nuclear power plants being constructed on the Moon.
https://web.archive.org/web/20110423155534/http://www.telegraph.co.uk/science/space/5711129/Uranium-could-be-mined-on-the-Moon.html

 Note that one of the locations the urianium was detected was the mysterious South Pole Aitken impact basin.

 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.

 Moreover, both the just launched Indian lunar south polar lander and Chinese lander to lunar south pole will contain a detector for heavy elements.

The upcoming lunar lander from Japan will also include an X-ray spectrometer for detecting heavy metals:

Japan gearing up to launch small moon lander next month.
By Andrew Jones published about 17 hours ago.
SLIM is scheduled to lift off on Aug. 25.
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.
https://www.space.com/japan-slim-moon-lander-launch-august-2023

 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.

Even the little Sojouner rover on the Mars Pathfinder mission had its own alpha-proton x-ray(APXS) spectrometer for measuring heavy elements:

 The APXS is the round instrument in front.

 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.

 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.

 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.

 These landers to the lunar south pole may return literally world-changing results. There has been speculation that the metal containing asteroid Psyche may contain many trillions of dollars of valuable metals.

 Then in this regard quite notable is this:

Weird 'Anomaly' at the Moon's South Pole May Be a Metal Asteroid's Grave
By Meghan Bartels published June 10, 2019
https://www.space.com/moon-south-pole-anomaly-metal-asteroid-impact.html

 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.

 Conceivably, the trillions of dollars of valuable metals speculated to be on Psyche could already be just next door!

  Robert Clark

SpaceX Dragon spacecraft for low cost trips to the Moon, page 3: Falcon Heavy for BEO test flights.

Copyright 2012 Robert Clark

The Falcon Heavy is planned to be tested by SpaceX by 2014. By using the Early Lunar Access (ELA) architecture we could have a return to the Moon by 2019, using either the Falcon Heavy or the SLS, as described in the blog post "SLS for Return to the Moon by the 50th Anniversary of Apollo 11". Note this would also be by the 2020 timetable set by the Vision for Space Exploration(VSE).
 This ELA architecture could be implemented either using either the Dragon capsule or the NASA Space Exploration Vehicle (SEV). The SEV is intended to be used for BEO missions perhaps for mission durations up to 28 days long with two crew members. Then the first Falcon Heavy missions would provide means for testing unmanned the SEV for BEO missions to the lunar surface, the Lagrange points or to near Earth asteroids.
 SpaceX needs to perform the test flights for the Falcon Heavy so they would pay for the costs of the launch themselves. For the lunar flights as discussed in the "SpaceX Dragon spacecraft for low cost trips to the Moon" post, the two Centaur-like upper stages might require in the range of $30 million dollars each. There would be an extra cost for the SEV but for these first test missions we might only use the prototype test vehicles now undergoing field tests with NASA's Desert RATS program. These prototype vehicles only cost in the few hundred thousand dollar range. This would put the cost to NASA in the low cost Discovery-class mission range.

2011 Desert RATS Overview

 Since these are to be unmanned test flights, ideal would be to "man" them with two Robonauts. This would dovetail nicely with the Johnson Space Center's Project Morpheus plan to send Robonaut to the lunar surface.  In regards to NEO missions, this is one of the planned uses for the SEV. For the manned asteroid flights NASA was considering, the mission time ranges were above 90 days. That would be unrealistic for flights just using the SEV alone. However looking at the Near-Earth Object Human Space Flight Accessible Targets Study (NHATS) page there are NEO missions with duration times of 34 days or less at stay times of greater than 8 days that could correspond to under 28 day mission times if we limit the stay time to a day or so.


      Bob Clark

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.
03.14.12

"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.
http://www.nasa.gov/mission_pages/WISE/news/wise20120314.html

WISE Delivers Millions of Galaxies, Stars, Asteroids.
04.14.11
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. 

http://www.nasa.gov/mission_pages/WISE/news/wise20110414.html 

The Wide-field Infrared Survey Explorer

All-Sky Data Release

March 14, 2012

http://wise2.ipac.caltech.edu/docs/release/allsky/

 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. 

http://www.jpl.nasa.gov/news/news.cfm?release=2012-164

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."

http://www.jpl.nasa.gov/wise/newsfeatures.cfm?release=2012-138

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.

http://www.jpl.nasa.gov/news/news.cfm?release=2011-060 

  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

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.
By DENNIS OVERBYE
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.
http://www.nytimes.com/2012/06/05/science/space/repurposed-telescope-may-explore-secrets-of-dark-energy.html

 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.
http://nextbigfuture.com/2012/04/planetary-resources-could-use-passively.html


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
http://www.independent.co.uk/news/science/up-telescope-search-begins-for-giant-new-planet-2213119.html

About that Giant Planet Possibly Hiding in the Outer Solar System...by NANCY ATKINSON on FEBRUARY 16, 2011
http://www.universetoday.com/83363/about-that-giant-planet-possibly-hiding-in-the-outer-solar-system/

 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
http://phys.org/news/2012-02-galaxy-swarm-nomad-planets.html

 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

Low Cost HLV, page 2: Comparison to the S-IC Stage.

Copyright 2012 Robert Clark 

The dry mass of the first stage of the vehicle described in the Low Cost HLV post was 1/20th the gross mass of the stage at 110,000 kg. Interestingly the propellant mass of the S-IC first stage of the Saturn V was about the same as in this HLV proposal, about 2,100,000 kg. Then it will be interesting to make a comparison to the dry mass of the S-IC stage. This page gives it as 130,000 kg:

Ground Ignition Weights.
http://history.nasa.gov/SP-4029/Apollo_18-19_Ground_Ignition_Weights.htm

 However, the Saturn V had a quite heavy first stage thrust structure:

SP-4206 Stages to Saturn.
7. The Lower Stages: S-IC and S-II.

Rosen apparently took the lead in pressing for the fifth engine, consistent with his obstinate push for a "big rocket." The MSFC contingent during the meetings included William Mrazek, Hans Maus, and James Bramlet. Rosen argued long and hard with Mrazek, until Mrazek bought the idea, carried the argument to his colleagues, and together they ultimately swayed von Braun. Adding the extra power plant really did not call for extensive design changes; this was Rosen's most convincing argument. Marshall engineers had drawn up the first stage to mount the original four engines at the ends of two heavy crossbeams at the base of the rocket. The innate conservatism of the von Braun design team was fortunate here, because the crossbeams were much heavier than required. Their inherent strength meant no real problems in mounting the fifth powerplant at the junction of the crossbeams, and the Saturn thus gained the added thrust to handle the increasingly heavy payloads of the later Apollo missions. "Conservative design," Rosen declared, "saved Apollo."²

http://history.nasa.gov/SP-4206/ch7.htm

Indeed it was heaviest single component of the S-IC stage, and so of the Saturn V:

S-IC.
2. Components.
http://en.wikipedia.org/wiki/S-IC#Components

 This online lecture of Dr. David Akin of the University of Maryland gives mass estimating relationships for various rocket components, taken from the reports NASA uses in designing rockets:


Mass Estimating Relations.
• Review of iterative design approach
• Mass Estimating Relations (MERs)
• Sample vehicle design analysis
http://spacecraft.ssl.umd.edu/academics/483F09/483F09L13.mass_est/483F09L13.MER.pdf

 On page 17 is given a relation between the thrust of the stage in Newtons and the mass of the thrust structure in kilograms:

M_{Thrust structure}(kg) = 2.55×10⁻⁴T(N)

 For 4 RD-171's at 7,900 kN each, this would be 8,000 kg. So we can subtract off 13,000 kg from that S-IC dry mass to get 117,000 kg. We're also using one less engine, so subtract off 8,350 kg for the one less engine. However, the RD-171 weighs about 1,000 kg more than the F-1, so add on 4,000 kg to get about 113,000 kg for the stage, quite close to the 20 to 1 mass ratio estimate. Note this is even without the weight saving alloys and composites now used.




  Bob Clark

Low Cost HLV.

Copyright 2012 Robert Clark

Credit: Modified from:
NASA's Space Launch System - Winners and Losers
by Ed Kyle, 06/17/2011
http://www.spacelaunchreport.com/sls4.html

 The announcement by two separate teams backed by highly regarded scientists and entrepreneurs for asteroidal or lunar mining means that quite likely there will be a significant market for super heavy lift. Note too that there were separate shuttle privatization plans with business models that involved privately investing perhaps $2 billion to produce a "shuttle 2.0". Quite key here though is a vehicle this size could serve as a super HLV without the ca. 80 mT shuttle orbiter. 

  I think at this point it is abundantly clear NASA can not be expected to make a cost effective launcher. An internal NASA estimate put the total development and launch cost of just four of the interim 70 mT SLS vehicles as $41 billion, which amounts to over $10 billion per launch.

 SpaceX has shown by using good cost-saving business practices to be able to produce a launcher at greatly reduced costs. They estimate their upcoming Falcon Heavy will break the $1,000 per pound barrier, or $2,000 per kg. Keep in mind then that increasing the size of your launcher is supposed to reduce your per kg costs. So likewise using good business practices, a super heavy lift launcher privately developed should be able to at least match this or exceed it. This would be in the range of $200 million per launch for a ca. 100 mT launcher, a radically reduced cost over that of the SLS. 

  I think consideration should also be given to an all liquid system. You would use the DIRECT team's Jupiter HLV hydrogen-fueled upper stage but instead of using the shuttle ET for the first stage to hold hydrolox, use the same sized tank for kerolox. This would give a super heavy lift vehicle without the SRB's.

 The DIRECT team wanted to use the same size tank to save on costs since you can use the same existing tooling in this case. However, a key fact is this will still be the case even if you switch to kerolox propellant. You would have to change the location of the divider between the fuel and oxidizer of course, but this is comparatively low cost compared to producing whole new tooling for a different size tank.

Now kerolox is a denser propellant so you are going to get a higher propellant load in this case. The density is about 3 times that of hydrolox, so lets say the propellant load of the first stage is now 2,100 mT. What about the dry mass? 

 At this point I think we should take note of the lightweight characteristics of the Falcon 9 that SpaceX was able to achieve. SpaceX has said the first stage of the Falcon 9 has a mass ratio better than 20 to 1. SpaceX did this by using well known techniques such as a common bulkhead design for the tanks. So we could follow this also to minimize first stage dry mass.

 Also, note that by scaling our propellant tanks up, we actually improve our mass ratio. So likely we can get an even better mass ratio than this for our large first stage. But using the 20 to 1 figure, or 19 to 1 for propellant to dry mass ratio, we get a dry mass of 110 mT.

 We need heavy thrust kerosene engines. I'll use the RD-171, with a sea level thrust of about 1,700,000 lbs, and vacuum Isp of 337 s. This will require 4 of the engines. This could be replaced later with the F-1 but using the RD-171 would allow you to start now on the vehicle development with better performance.

 For the specifications of the upper stage, the DIRECT team went through several versions of their Jupiter super heavy lift vehicle. I'll use the one they referred to as Jupiter-246 Heavy, LV 41.5004.08001. For whatever reason, the DIRECT team no longer has the specifications for their vehicles up on their web site. This version's specifications are within this post to the SpaceFellowship.com forum:


Re: An SSTO as "God and Robert Heinlein intended".
Posted on: Sat Mar 12, 2011 9:49 pm
http://spacefellowship.com/Forum/viewtopic.php?p=44979&sid=3d11bfaff22840cdcd239a4c452c48d6#p44979

though you'll have to register on that forum to view it.

 This version used a propellant mass of 190,849 kg, a dry mass of 11,825 kg and 6 of the RL-10B2 engines, with an Isp of 459 s. Other versions have used the new J-2X engine, but just 6 RL-10's are likely to be cheaper. 

 This version's interstage and payload fairing were at about 4,000 kg each. We'll round off the upper stage propellant mass to 190 mT and dry mass to 11 mT. Then using a 9,150 m/s delta-V to orbit we can estimate the payload to orbit as 145 mT:

337*9.81ln(1+2100/(110+201+4+4+145)) + 459*9.81ln(1+190/(11+4+145))=9,176 m/s

 Admittedly, this payload estimate seems high so I plugged some numbers into John Schilling's "Launch Vehicle Performance Calculator" and got:

Mission Performance:Launch Vehicle: User-Defined Launch Vehicle
Launch Site: Cape Canaveral / KSC
Destination Orbit: 185 x 185 km, 28 deg
Estimated Payload: 102573 kg
95% Confidence Interval: 86317 - 121993 kg

 So it's still, likely, ca. 100 mT.

 There are several variations on this theme. For example to save on development costs we could use the Ariane 5 core stage as the upper stage. Since the ESA was amenable to using it for an upper stage for a re-booted Ares I, i.e., ATK's "Liberty" rocket, they would likely be amenable to this as well. You could also make this be parallel staging with cross feed fueling to improve performance.

 Another possibility would be to make the upper stage also be kerosene-fueled. Say you used the same light-weight tooling and tank diameter for the hydrogen fueled upper stage but using now kerolox propellant. Again, you could improve performance by making it parallel staged with cross-feed fueling. But this has an additional advantage in that you could take one of the engines off the first stage to use it for the upper stage. This would result in a lower dry weight for the first stage. The upper stage though would then be somewhat overpowered using a RD-171, so it may suffice instead to use a RD-180 just for the upper stage.

 



   Bob Clark