Beyond Augustine

Mr. Wingo makes some sense.

I agree with the ideas of a Shuttle derived launcher, though am unconvinced whether it is that much easier, that much faster, or particularly whether it from a standpoint of long term cost, adaptability or sustainability, whether a side-mount or a Jupiter is the better option. I think a serious study needs to make that trade.

Assuming you go with Shuttle derived and reestablishing the Shuttle supply lines, then I think consideration needs to be given to continuing to fly Shuttle. Its safer now than it has ever been. But I am not sure it is affordable to continue to maintain the Orbiter. And it will take some considerable effort to reestablish supply lines in a timely manner. And while people consitnue to talk about this option, we keep flying the remaining Shuttles at the same rate and laying off the KSC Shuttle workers according to plan. So if its not done in a timely manner, then Shuttle could wind up in a down period durng which workers lose skills and we could have an alternative LEO capability before Shuttle is brought back online.

I am not convinced that moon first is affordable or acheivable. Mr. Wingo leaves out development costs for the return vehicle and for the lander. Can you afford to do those along with everything else that is required to orchestrate the lunar effort ? I think you wind up pretty much back where Constellation was; and Augustine said that situation was not sustainable.

The physical plants required for lunar ISRU will require significant mass to be landed. You need not only the capability of sifting and separating the lunar materials on massive scales, but the distilleries for producing fine aluminum, iron and other metals, or oxygen, hydrogen and other volatile fuels and for storing them. And you will need the machinery for manufacturing the system components. I'd like to see some serious research and trades on what these efforts will require, in what order, and at what cost and budget.

The Flexible Option could make use of ISS derived elements and systems already available at minimal additional, marginal cost. Those elements need to be mated with an advanced propulsion system. The two need to be placed in orbit, along with fuel for the advanced propulsion system. These could all go to the ISS for integration and preparation. All of these components could be launched with the world's existing launch systems, since no element needs to be significantly larger or more massive than existing typical ISS elements. If the vehicle departs from ISS in LEO, and it returns to ISS in LEO, then you do not require new launchers, new earth-LEO-return capsules, or new lunar or planetary landers. Combine this development effort with the development effort for a Shuttle-derived launcher, and you keep most of the existing space workers doing what they already know how to do.

The Flex Path system described, could be flying within a few years without huge new funding expenditures.

I'd like to see numbers on the ease of material recovery and use from asteroids and comets, compared with ISRU on the moon and launch from the moon to other solar system destinations, compared with transfer from planetary orbits to earth orbit or the lunar surface.

I absolutely agree that we need a lunar base program. That's the key to everything, IMO.

Plus a lunar settlement program would finally end the Moon vs. Mars debate since once you have a lunar base, a Mars settlement program almost immediately turns into the next venue for our manned space program.

If we had established a permanent base on the Moon back in the late 1970s or 1980s, we'd probably already be on Mars by now!

Marcel F. Williams

Note that "fitting within the current budget profile" was basically a non-starter. Doing that would require a 2010 retirement of the Shuttle, an early retirement of the Space Station (irritating our international partners), and delaying creation of a new launch vehicle.

I think that IS one of the options, it's just a really bad one.

I'd like to see numbers on the ease of material recovery and use from asteroids and comets, compared with ISRU on the moon and launch from the moon to other solar system destinations, compared with transfer from planetary orbits to earth orbit or the lunar surface.

The numbers are actually easy. The Moon is three days away, with two week windows for launches. ANY asteroid, or ANY comet, or Mars, is a 2 year revisit window. It is a time cost of money thing. You also have telepresence operations by Earthbound crews possible for lunar ops (the oil industry is doing this a lot these days), which is a force multiplier.

The Moon is also much easier to work with operationally as the navigation in Cislunar space is far lest costly (GPS works to about 100,000 km) than interplanetary navigation.

The lunar base gives you the flexible path very quickly, but the flexible path does not give you the Moon, or anything else but some nice pictures and a few samples.

"...But I am not sure it is affordable to continue to maintain the Orbiter..."
The cheapest COTS bidder to win was SpaceX with an award of 1.6 Billion dollars to launch 44,000 lbs over 12 flights. That is a cost of 133,333,333 per flight or 36,363.64 per pound.
The FY09 NASA Space Shuttle Operations budget was 2.9871 Billion. NASA launched 4 Shuttle flights so the rough per flight cost is 745,425,000 dollars. Now let’s examine the STS-128 resupply mission. Subtract out the cost of launching 7 astronauts using the cost of the only alternative, the Soyuz at 50,000,000 per astronaut or 350,000,000 dollars and you are left with 395,425,000 dollars for the cost of cargo. The MPLM delivered 15,200 lbs and the Ammonia Tank Assembly was listed at 1,800 lbs (have to ignore middeck and water and O2 consumables transferred because I can't find the info on these).
So it cost 395,425,000 dollars to fly 17,000 lbs of supplies or 23,260.29 dollars per pound.
Okay that's COTS 36,363.64/lb vs 23,260.29 for Shuttle. Even without a Phd. I can see that it is 13,103/lb cheaper to deliver supplies with the Shuttle. Granted these are estimates that are equivalent to back of the envelop/napkin calculations but if that type of calculations are good enough for Mike Griffin they are good enough for me.
This is not meant to say that we don't need COTS cargo and in fact I believe that the US should proceed with COTS crew as well. As has been shown with the 2 Shuttle failures we need alternative access to space. What would have happened if the Soyuz continued to have re-entry problems?
I just get tired of people maligning the Shuttle and not giving the proper facts. The Shuttle is very good at what it does and is proving that it is cost effective vs the alternatives. It may not be as cheap as we were promised or would like but so far, no one has come up with anything cheaper. And Soyuz has had 2 loss of crew events, same as the Shuttle has while flying less flights and only 1/3 the number of crew members. So until it or an alternative crew transport exceeds the flight count of the Shuttle the jury is out on safety.

Using advanced propulsion systems, like the VASIMR already in development, none of the NEOs, or Mars or Venus, are much more than 1-2 months away. Flex does not require more than the one or two solar system transit ships to be developed-literally one or two vehicles and could be done to large extent with the existing workforce. A lunar base requires the Earth to Moon transit vehicle, and the lander, and ascender, and the base infrastructure, and most of it needs to be built for each individual mission since it is largely throw away.

Sure, a moon base would be great, but its not affordable on the current budget.

On the current budget, assuming Shuttle is shut down, you get that one budget to apply to one new start. I'd suggest thats the heavy lift. Orion won't be built because a commercial LEO vehicle can/will take its place, likely at lower cost and at much less exposure for the US government, and Orion has little value given the long term development schedule, huge volume but limited mass capacity.

This also means that the Flex vehicle has to be an offshoot of existing long duration vehicles and systems like ISS. There is essentially no money for anything additional.

If Orion and Ares 1 were $100 billion, and Ares 5 likely another $100 billion +, and Altair even more, and none of these are ready for 25 years or longer, then Mr. Agustine has already told Mr. Wingo that the money is not there for the moon base. An alternative to the heavy lift and Flex option, might be some small EELV launched lunar technology unmanned landers that could show some limited lunar soil processing techniques. You might be able to develop the next step after that once ISS is shut down in about 20 years.

With this Flex scheme and the existing budget you get out of LEO within 10 years and kick start a commercial launch capability and commercial human orbital transportation, hopefully both at considerable cost savings, in part due to avoiding the government bureaucracy and in part due to competition. Not only do you get out of LEO in a decade, but the commercial entities lap the government capabilities and could be thinking about a lunar base in a couple decades.

With the Constellation lunar base scheme, or most other schemes that hope to do the moon first and soon with government resources, you won't get to the moon for at least two to three decades, but only if the US government had a lot more money to spend.

A lunar chemistry that replaces carbon in say plastics with an ISRU element such as silicon is needed. Removing hydrogen from the processes would also be useful.

We have had X-prize "lunar landers" these could be developed into real landers. A lander that can drop its payload and refuel could make a good level 3 X-prize. Remote controlled landers would also make a first customer for the ISRU LOX. these can be in action whilst the heavy lift LV are developed.

Don't think that's true. Once you have a highly capable lunar base with refineries, maybe, but you won't get such a thing for a LONG time, even with a $3 billion plus up.
A 2-year revisit window isn't that much of a disincentive for NEOs, as we'll probably only be able to afford to go the Moon once or twice a year anyway. One sets up an autonomous ISRU station on a NEO, and let it work for two years. No down- or up-mass propulsion penalty.
Interplanetary navigation is probably less of an issue for a NEO visit than ops around a very nonspherical asteroid.

Why do you think that it will take a LONG time? Why does it have to be a government entity at all doing the fuel processing. Again, if you look at the physical chemistry involved, it is not that big of a deal to get oxygen or metals from regolith. The water is just a bonus.

Talk to any venture capitalist about 2 year timeframes vs 2 week timeframes. It is simply untenable to state that the difference does not make a dramatic difference in economic viability.

As far as autonomy goes, you have to be kidding. An autonomous plant working for two years without human intervention. We have never ever been able to do that here on the Earth, what makes you think that we will in space, within the budget that we have. Hell look at how much money the James Web Telescope costs and it is a trivial system mechanically to an automous fuel plant.

@A.M. Swallow

Exactly the point. At some point people are going to realize that the Moon is a pretty friendly place to operate.

Mars is not the right destination for "human expansion into the solar system" (the ultimate goal set by the Augustine Commission). This goal implies a need for physical and economic sustainability. I don't see how we can achieve either on our metal-poor Moon where water may be difficult to extract. Asteroids have the low gravity wells to get there and back more easily, and resources to sustain human life, provide rocket fuel and building material in space, and perhaps even eventually return a profit to Earth (e.g., platinum, cobalt). Space-based solar power could also help meet key national strategic objectives such as energy independence and reducing greenhouse gas emissions. Why did the Augustine Commission say Mars is the ultimate destination? Because it is there? Because we have lived on the surface of a planet for so long that we just feel more comfortable knowing which way is up? Because countless science fiction books and movies have excited our interest in the red planet? With Mars as our ultimate destination, there is a very real danger that we will succeed, just as we succeeded with President Kennedy’s goal of putting a man on the moon. And in succeeding we will sow the seeds for another 40 years of shrivelled hopes and barren efforts; we will have spent our last dollars and exhausted the soil of public tolerance for human space flight… again.

I think that shows the Shuttle concept of a 1.5 stage to orbit RLV definitely worked out well; it does save money.

However the requirement for crew keeps it from living up to its full potential; it can't just launch a satellite without putting humans at risk.

So they don't, and the flight rate suffers, the base cost becomes more significant and there is all the extra complexity and mass anyway.

A crew free shuttle - not a disposable SDHLV, but like the current ones - could seriously boost flight right by being a viable sat launcher, could be less complex & expensive and could lift more in one go.

Why is this never considered; what am I missing?

Way to go Dennis, bang on as always!

FYI: I've proposed a Lunar Landing PAD challenge to NASA for a new challenge - robotically sintered lunar simulant fused into a landing pad. Tested with NGLLC winner's rockets. Kind of the next step of the regolith challenge and necessary for repeated landings at a single location.

(funny that the spell checker at this site is complaining about 4 of the words in this post - guess which? :D )

Two points:
"Using advanced propulsion systems, like the VASIMR already in development, none of the NEOs, or Mars or Venus, are much more than 1-2 months away."

Vasmir, and all of the advanced electric propulsion systems (ion engines, stationary plasma thrusters, magnetoplasmadynamic thrusters, etc.), require very large electric power sources. If we want to use these for fast space transportation, we need to get nuclear reactors in space-- something which we are not currently allocating any funds to do. So if this is the path you're recommending, step one is going to have to be "restart a space reactor program."
(Extremely large solar arrays would also work-- but these will have to be extremely lightweight, and there isn't a very-large-and-very-light solar array program at NASA, either.)

"A lunar chemistry that replaces carbon in say plastics with an ISRU element such as silicon is needed."

Silicon does not substitute for carbon, despite being a group-IV element, in plastic. If you're thinking of silicones, you need to know that silicone is a group of organic compounds incorporating silicon. They are not carbon-free.

(Fortunately, plastic is not really what we need most in space anyway-- the major structural materials of aluminum, titanium, and steel are all things that can be manufactured on the moon from lunar materials.)

I like the napkin math comparing Falcon9 to Shuttle. It inspires me to run the numbers myself. One objection to Mr. Wingo's setup is dividing the entire COTS contract cost into the #'s to orbit. The equivalent shuttle scenario would be starting with its entire contract cost, including at least some portion of its development, perhaps including upgrades.

Vasmir, and all of the advanced electric propulsion systems (ion engines, stationary plasma thrusters, magnetoplasmadynamic thrusters, etc.), require very large electric power sources. If we want to use these for fast space transportation, we need to get nuclear reactors in space

Here is another myth that needs to be dispelled. While it does take a lot of power to power stationary plasma thrusters and other ion sources (I do agree at least partially on VASIMIR as much as I love the tech), the amount of power necessary for very substantial payloads (30-60 tons) from LEO to lunar orbit is entirely doable today.

We designed a completely workable system under the H&RT contracts in 2005 and 2006 and that system is the graphic for this article! We need to do some more work in that direction.

I think there is a misread from the space Advocate/enthusiast community on what the "Flex Path" is. Recall that the VSE was a pay as you go approach and there have been insufficient funds to support it. The Flex approach is a path to nowhere as it is a further erosion on HSF and will not have appropriate funding. Because it tries to do everything it will wind up doing nothing. IMO at the next level of detail it will struggle to get consensus and advocacy and will wander for a bit all the while NASA will continue to build something ( have to keep those constituents employed) that will probably not match what ever flex eventually comes up with. Building capability at this level without a mission and having staying power, is unprecedented in the space business and bound to fail. Just look at all the recent X projects. All in graveyards everyone when will they ever learn. This is headed down that "path".

NASA's budget is poised to move in one of three directions: Up, down, or sideways, relative to inflationary growth.

Based on past, present, and future pressures observed in the Ares-I program, we can eliminate an expected upward movement of NASA's budget.

@ Geoffery
Silicon does not substitute for carbon, despite being a group-IV element, in plastic. If you're thinking of silicones, you need to know that silicone is a group of organic compounds incorporating silicon. They are not carbon-free.

True just replacing carbon with silicon does not work. However bowels made out of fibre glass (silicon oxide) can replace plastic bowels. The same applies to the comfortable part of chairs.

I do wonder if silicon or ISRU magnesium can be used to remove the oxygen from iron ore.

Do the numbers.
Electric propulsion systems are power hogs. All electric propulsion systems.
This a law of physics: the power required (per Newton) is directly proportional to the specific impulse, so if your system is producing high specic impulse, you'd better have a pretty impressive power system.

As a real world example, the Deep-Space 1 ion propulsion system produced 0.1 Newton at 2.5 kilowatts. Scale this up from the 400 kg that DS-1 weighted to the "30 to 60 tons" you're talking about, and scale up the thrust so that you get somewhere in a few weeks instead of six months, and you're getting into Megawatts.

Or, phrasing it the other way, if you don't have Megawatt class power systems, you'd do just as well to go chemical.

Ad Astra claim 200 kW can take 7 tonne of payload from LEO to low lunar orbit in about 6 months using a VASIMR. 35 metric tons takes 1 MW. There is a big saving in propellant.

Geoffry

I have run the numbers, a lot of them. A 500 kW tug can take a 30 metric ton payload from ISS to Low Lunar orbit in about 4 months and return in less than 45 days.

DS1 is not a good example. Gridded ion thrusters are crap for climbing out of a gravity well. A Hall thruster is much better at this. You run it in low ISP/High thrust to get above the inner van allen belt then move to higher ISP/lower thrust to get the rest of the way there.

Actually, your law of physics is off a bit as well. There is an optimum ISP/thrust point with Hall thrusters that is between 2500 and 3000 in ISP. This is set by the operating voltage. Do a bit of research on the BPT-4000 from Aerojet.

The ultimate measure of how good a Hall thruster is, is the system efficiency. A really good hall thruster can approach a number as high as .65 and this has more influence on the ultimate performance than any other variable.

Hall thruster systems at half a megawatt are perfectly fine for use in Cislunar space or in interplanetary trajectories.

First of all it is always delightful to read articles such as this.

I have some suggestions/questions.

1)How about replacing the SSME with the RS-68 on the Shuttle side mount? Would the low production cost offset the development cost of integrating it? Or guess the question is: How long would it take for the savings to be realized? After all, the SSME was built to be reused and the RS-68 is intended for one time use.

2)Electrically powered propulsion should be used as a "slow-boat" with low wattage and a constant burn. Who cares if it takes 3 weeks for a pallet of supplies to arrive as long as you plan for it?

3)A 2-5K lbs ISRU demo prize should be a first priority.

So lets recap:

1)Shuttle side mount with RS-68 engines.
2)Reusable ion engine powered Earth-Moon cargo hauler.
3)Resuable lunar lander.
4)ISRU.

There's your infrastructure. Any questions?

Geoffry

I just looked up your bio. You need to talk to David Manzella, there at Glenn. Ask him about the performance of the NASA 457M Hall thruster. Tell him you know me. Maybe he can convince you.

"scale up the thrust so that you get somewhere in a few weeks instead of six months"

Or just let it take six months?

Many of you are too inside. You can't see the forest for the Ares. You want to debate the most appropriate technologies, but the question right now is politics, money, ultimate goals and objectives, and the destinations that derive from them. I support the Augustine Commission's "ultimate goal" of "human expansion into the solar system." I also support the Committee's recommendation that human space flight objectives should "align with key national objectives." What would this goal, and these objectives, require? Physical sustainability, which means access to in-situ resources. Economic sustainability, which means solar or metals, or something we haven't thought of yet, to make it profitable (but finding that thing should become a priority for research; no one in 17th Century Jamestown had a clue how to make the first English colony in the new world profitable; it took 11 years for them to discover the solution: tobacco). And finally, "key national objectives." What does that mean? Space-based solar could increase our energy independence and reduce greenhouse gasses. What else? Rare earth metals are in short supply, and China seems to have a lock on supply, but we don't know of anywhere in space where they are enriched. Platinum and cobalt from near Earth asteroids? Long-shot. Maybe. But there are things to try. Getting the goals and objectives right, from which we will derive possible destinations, is the first priority. Stop talking about which launch or LEO-to-somewhere transfer system to use. Start focusing on where we're going first, and and then decide what technologies we need to get there.

Why? Where do we really want to go? Let's figure out these questions first.
--tchad (similar name)

"The lunar base gives you the flexible path very quickly, but the flexible path does not give you the Moon, or anything else but some nice pictures and a few samples." [Dennis Wingo November 4, 2009 4:24 PM]
With respect to someone far more knowledgeable in this field; I must disagree. My 'take' from the HSF Commission concerning the "Flexible Path" is a long duration habitat (possibly a critically developed European "Space Trailer") ...parked at L1 as a way-station and service camp for the US Cryo-Propellant Depot. The Russians may be amenable to putting OPSEK on hold in favour of their LOS and a Critical Path (Hypergol) Lander to the surface. Russian Boots and Footprints! Thus we have two refuges in Lunar proximity and locations where time critical Teleops may be enacted. But NO surface base! Instead it will be Telerobotics, Telerobotics, Telerobotics, delivered and supported by SEP/VASIMR slowbots, that will return to the Moon. IMHO the Flexible Path is actually geared to provide the in-space infrastructure to support the remote exploration of the entire Inner Solar System: Venusian atmosphere to Mars surface. All from within the comfort of your mobile home. (Trailer parks on Phobos!)

Returning to the Moon: whilst in the medium term some form of base camp (radiation shelter) will be required, the construction of any Base (with a capital B) is somewhat down the road. Prospecting, ISRU, whatnot can be carried out from the comfort of our schools and a more leisured approach taken before picking where we should put down Roots rather than Boots!

NEO class missions are a good deal down the road. But are clearly exploring beyond Earth Orbit! Personally I would be challenging NASA to go out to a BIG PGM meteor. And bring it back! Now there's a sample.

The goal of all human space endeavors should be to expand mankind's presence in the solar system in my opinion. There is only a limited amount of resources on our quaint little pale blue dot. So, I think it the moon is a great choice to start. It has everything humans need to live (with a little ingenuity) and most importantly some gravity. I think the L points are just hubs to support that and the exploration/usage NEOs. So the answer to your question for me is.. everywhere. This is just how we begin the process.

Geoffrey wrote: "This is a law of physics: the power required (per Newton) is directly proportional to the specific impulse."
Dennis W. replied "Actually, your law of physics is off a bit as well. There is an optimum ISP/thrust point with Hall thrusters that is between 2500 and 3000 in ISP."

Huh? The fact the power required is proportional to specific impulse doesn't me that there wasn't an optimum Isp. It is quite correct, optimum Isp does exist for each mission type... in fact, I've written papers calculating it. That does not affect the fact that power required is proportional to specific impulse. (It does mean that extremely high specific impulse is not terribly useful.)

That does not affect the fact that power required is proportional to specific impulse. (It does mean that extremely high specific impulse is not terribly useful.)

The efficiency of a Hall thruster determines overall mission performance. As efficiency climbs, the amount of fuel to conduct a mission decreases. In our study in 2005, we found that with about 20k kilos of Xenon you could do the round trip to the Moon with a 500 kW thruster, using the NASA 457M as the reference thruster. With any Hall thruster it is the total performance (thrust/Isp), not simply ISP and that is the curve that I am talking about.

We solved the two key roadblocks that previous designs had, which was the slip rings required and the problem of power distribution in general. If you want a copy of the contractor report I would be more than happy to send it. It was reviewed by all of the major groups (GA Tech, Michigan, AFRL, and NASA Glenn [Jankowski and Manzella]) and no flaws were found.

We kept the solar arrays pointed inertially at the sun and rotated the thrusters. We developed the algorithms for minimal plume impingement and maximum efficiency. It is modular and extendable to N size with N being a number between 1 and probably about 20 segments.

A wise man once taught me that no matter how many times you count the people on the bus, you won’t learn which way to turn at the next crossroads. Engineers want a formula and mathematics to tell them the right answer. And we are quite good at using these tools. But some of the answers we want are beyond equations to address. Once the goal and the constraints have been identified, engineers can determine an optimum solution. But it is up to our nation, its people and leadership, to define the goal and the constraints. We space junkies have our own goals, though no consensus among us. We want to engineer this problem and come up with “the right answer”. But this particular problem is in the realm of politics and national priorities, not engineering. And we need to find some experts in this realm to provide the needed leadership so we engineers can get back to work.

The fear I have with open ended flexible paths and +20 year goals is that a present political administration will always be happy to write checks its successors refuse to cash. It costs Obama nothing to say "lets go to mars in twenty years" when he's only got seven remaining, at best.

"We space junkies have our own goals, though no consensus among us. We want to engineer this problem and come up with “the right answer”"

I think the problem is a little more simple than all that. From a budgetary standpoint We know what the right engineering answer has to be.
The per-mission cost of space travel is just too high to do much of anything. The situation is so untenable that whatever adventure we have next is assured to be as short lived as the last.
It doesn't matter where we go, we arrive back at this problem.

The solution is to make space travel more affordable so we don't have to rely on all the worlds governments to foot the bill for manned exploration.
We need to skip the whole idea of saving money on a shuttle derived system to focus spending on building the vehicles we wanted our space shuttles to be.
The end result would jump start the development of space and exploration much more than a few missions to mars would.

"In our study in 2005, we found that with about 20k kilos of Xenon you could do the round trip to the Moon with a 500 kW thruster,..."

Wow! That's a significant fraction of the Earth's annual production!

"There are definite driving paths from the north polar region Peary Crater permanently lit zones down to Mare Frigoris,..."

The best data right now (Kaguya) indicates there are no permanently lit (i.e. year round, excluding eclipses by the Earth) zones on the Moon: North or South Pole.

http://www.agu.org/pubs/crossref/2008/2008GL035692.shtml

Noda, H., et al.(2008), Illumination conditions at the lunar polar regions by KAGUYA(SELENE) laser altimeter, Geophys. Res. Lett., 35

We might be able to follow the light near the poles though using mobile assets.

The latest LRO-LOLA results will help get a higher resolution,definitive answer.

Wow! That's a significant fraction of the Earth's annual production!

I have a letter from a leading supplier of Xenon gas, that with a 36 month lead time they can increase production to whatever level we need to support SEP systems.

There is an alternative as well with Krypton or even mixed Xenon/Krypton propellants. Krypton is about 5% less efficient than Xenon according to measurements by NASA Glenn (there are papers about this at the JPC).

This is a cost issue more than anything as Xenon is about 20 times more expensive than Krypton. Both are produced as a byproduct of liquid oxygen production.

The best data right now (Kaguya) indicates there are no permanently lit (i.e. year round, excluding eclipses by the Earth) zones on the Moon: North or South Pole.

Yep, but we also know that in the summer that there are places in the North (from the research of Bussey/Spudis). There are also indications that a 100 meter tall tower would be in the sunlight all year. Putting solar arrays (large ones) up on a tower like this (plenty of ISRU metal for the platform), then the problem is solved. This would be far cheaper than a nuke, at least in the near term.

If you look at their plots (google them for the papers), the spots are in four locations along the rim of Peary crater. I have extensively researched the Lunar Orbiter images of this area (and am waiting for LROC images) that indicate that along that ridge there is a location that has a nice ramp from the best lit spot to the floor of Peary A. The floor of this crater, in smaller craters, is where the best northern water sources all. These are much more accessible than the floor of Shackelton, which has a terrible 45 degree incline down to a very small floor. There is also a nice exit path toward the southern end of the crater than goes almost straight down to Mare Frigoris.

"I can see that it is 13,103/lb cheaper to deliver supplies with the Shuttle."

Interesting analysis. Even though this is all back-of-the-napkin, I think there are two factors which could make a huge difference in the cost estimates for Shuttle. One is the hidden fixed costs of the SSP. I don't have a good number for that, but I think that could easily double the payload costs. Unfortunately cost estimates for Shuttle extension were never released by the HSF panel. The second factor is the cost/benefit of launching astronauts. I don't think it's reasonable to just subtract $50 million for each astronaut, based on the Soyuz prices. For one thing, how useful are those astronauts for delivering cargo if COTS can do it unmanned? Also, the Shuttle spends 10 days at the ISS, while Soyuz lasts ~6 months. So, let's say those astronauts are useful while they're up there. Soyuz can put an astronaut on ISS for $300,000 per day. That means you can subtract $3 million at most per astronaut from the Shuttle. Plugging those numbers back in, we arrive at $42,000/lb for Shuttle, not $23,000/lb. That's $6,000 more per pound than COTS, not counting fixed or re-certification costs.

Those 7 seats for two weeks aren't for staffing anyway; they're for construction crews.

If the station is done, those seats don't get filled.

If you're flying the shuttle to lift cargo, those seats aren't only surperfluous, they're a liability; you're risking lives.

You can't just wave your hand and say space will be risky. This risk is superfluous.

And anyway, what are you going to lift?

The Shuttle can and does lift more cargo per dollar when stuffed with crews and payload. But once the station is done, the demand for either will drop dramatically.

How do you numbers look when you have 2 crew on 2 shuttles a year?

A key feature of the Shuttle was the ability to field an airlock, robotic arm, large hardware and a full crew of specialists.

But we have a space station with an airlock, arm and with Dragon, Cygnus, H-IIB and others, it will have a complete up & down supply chain and perpetual staffing.

Let's build things _there_.

You can even reach the lunar poles from ISS's orbit, as Wingo has described.

"One is the hidden fixed costs of the SSP. I don't have a good number for that, but I think that could easily double the payload costs."
Nice conspiracy theory. "Hidden costs". But actually, since we don't see a line by line budget for all activities at all NASA centers you are correct.
One thing that I don't understand is that while workers at KSC are getting laid off why isn't the active astronaut corps being reduced? As I pointed in other posts if you are going from orbiting 28 astronauts per year to just 4 you should be able to reduce the number of active astronauts from 80 to say 16 with the layoff of all of the personnel required to support the surplus 64 astronauts. But this was pointed out by Mr. Augustine during his news conference on the release of the full document when he stated that the NASA administrator really can't do his job and cut costs when programs are cut because all of the centers are politically protected. So I guess my point is that you are going to have these hidden costs even when the shuttle is retired and we are going to be getting absolutely zero back on these expenditures.

"There are also indications that a 100 meter tall tower would be in the sunlight all year."

My paper on the subject using the 1997 Goldstone Solar System Radar elevation models of the lunar North Pole indicated that you need >1500m towers to eliminate shadowing. The north pole is flatter than the South thus you need a shorter tower to do this. But the South Pole requires >3km towers to eliminate terrain shadowing.

Can you provide a reference indicating the 100 meter one is enough to eliminate terrain shadowing year-round?

Can you provide a reference indicating the 100 meter one is enough to eliminate terrain shadowing year-round?

Nope, it was beer talk with some folks at LEAG last year.

1500 meters is not frightening if we are making a lot of ISRU Inconel.

"These are much more accessible than the floor of Shackleton, which has a terrible 45 degree incline down to a very small floor."

The Kaguya data shows from one part of the Shackleton Rim that the average slope from top to bottom is ~30 degrees. It could be less with judicious paths. Might be a little nerve-racking to drive ~10km like that, but is within the LER specs. But I would want to check it out roboticly first because the dirt attributed may be a problem.

The Kaguya data shows from one part of the Shackleton Rim that the average slope from top to bottom is ~30 degrees. It could be less with judicious paths. Might be a little nerve-racking to drive ~10km like that, but is within the LER specs. But I would want to check it out roboticly first because the dirt attributed may be a problem.

I would really like to see your source on that. The images that I saw at LEAG last year made it look really bad.

"I would really like to see your source on that."

The JAXA folk released the Kaguya LALT full dataset on Nov 2. This dataset has each datapoint.

https://www.soac.selene.isas.jaxa.jp/archive/

This was the "preliminary release version" if you are interested...
http://www.kaguya.jaxa.jp/en/science/LALT/The_lunar_topographic_data_e.htm

I can send you some nice surface zooms of Shackleton, they are very interesting. Looking at the South Pole with zero degrees longitude at the top of the image, the more reasonable path ( less than 30 deg slope) is at the 1-2 o'clock position of the crater. Starts at 900m and goes down to -2773m with about 8 km of driving distance.

These are favorably compared with the LRO-LOLA data being generated.