And Just When We “Abandon” It

More water has been found on the moon. At the north pole this time.

Although the total amount of ice depends on its thickness in each crater, it’s estimated there could be at least 1.3 million pounds (600 million metric tons) of water ice.

You could make a lot of margaritas with that.

[Monday evening update]

Here’s a lot more from Paul Spudis (who more than almost anyone should know).

40 thoughts on “And Just When We “Abandon” It”

  1. Looks like Keith has a little trouble with English-metric conversions.

    1.3 million pounds equals 600,000 *kilograms* or 600 metric tons — not 600,000,000!

  2. I thought that seemed a little overimpressive, but was too busy to do the math at the time. Paul Spudis seems to have corrected it in comments (not just the conversion, but the actual number).

  3. Strange, I’m not seeing any comments there.

    The NASA Mini-RF website, which is apparently the original source of the story, states, ” it’s estimated there could be at least 1.3 trillion pounds (600 million metric tons) of water ice.”

  4. Whatever the amount of water there is, it’s all under the control of The Lunar Authority. 🙂

  5. It seems obvious to me that we need decades of study with robotic precursor missions and ISRU demonstrations before lunar ice can be utilized. And you really need to ask what you want to utilize it for.. is it for supplying some lunar base, like drinking water and oxygen? Or is it for launching to L2 to make propellant to reduce the size of launch vehicles required to explore the solar system?

    In either case, the success or failure of those precursor missions completely determines the architecture needed to take humans beyond LEO, so why would you start working on that now (or 4 years ago)?

  6. It is 600 million metric tons according to Spudis.

    This is in the middle of the range of estimates as far back as Arnold’s original paper in 1979.

    This is to be expected considering that the emplacement mechanism is the solar wind (for the majority of it anyway).

  7. If we actually go through with “abandoning” the unaffordable infrastructure of Mr. Griffin, et al, we can now look forward to both lunar hotels…and ones with swimming pools.

    🙂

  8. Alan, you’ve highlighted why the moon vs mars debate is silly: Mars has water AND it is covered with salt. Further out, Io has gaseous salt volcanos which launch salt to watery Europa, and even further out, thanks to the geysers of Enceladus, Saturn’s rings have both salt and ice conveniently off-planet.

  9. With water at both poles, the leverage offered by an EML transfer station and reusable lunar landers only increases.

  10. The suggestion is that much of it is relatively pure, inferring that it might also be relatively easy to extract. I was fearful that it might consist of a very hard composite of ice and rock.

  11. Bob-1 Says:

    March 1st, 2010 at 9:28 pm
    … Mars has water AND it is covered with salt. Further out, Io has gaseous salt volcanos which launch salt to watery Europa, and even further out, thanks to the geysers of Enceladus, Saturn’s rings have both salt and ice conveniently off-planet.

    McGehee Says:

    March 2nd, 2010 at 5:24 am
    Ice and salt is all well and good, but without lime…

    Can you make Tequilla from the moon water ice? Do we need to bring the Blue Agave with us, or do we need to go all the way to Neptune for that?

    Oh hell, I’ll just drive to the liquor store!

  12. I ran across an article last year about some researchers making diamonds from tequila. Perhaps the reverse is possible as well? ☺

  13. You know, with the way the rocket equation goes it would make sense to use the uncracked water as propellant!

    Land with empty propellant tanks (easy to arrange!), fill the tanks with dirty water. Heat the tanks to 300C or so to keep the pressures low. Now just vent the tanks through a nozzle (presumably mostly in liquid phase), making sure that any ice made by evaporative cooling also goes out the back (instead of trying to keep the heat of the chamber from burning the rocket, you have to keep the cold of the chamber from freezing the fuel!).

    The delta-v to leave the moon is roughly 2km/s. You could probably just barely get 100 seconds Isp from the water, so a lunar departure stage would only need a mass ratio of 7.5 or so. Earth return is harder, but only moderately so – the mass ratio goes up to about 20.

    Not having to bring you propellant with you from Earth – priceless!

    Of course, a more reasonable approach is probably a tri-propellant engine. Take a normal engine, and put in plumbing to dump water into the chamber near the throat. You run the main engine with just enough normal propellant to vaporize the water – and your (water) Isp probably doubles!

  14. You know, with the way the rocket equation goes it would make sense to use the uncracked water as propellant!

    I don’t think you’re going to get 100 seconds of Isp with that kind of steam rocket, and the mass ratio would be lousy. Even a nuclear steam rocket doesn’t get much above 200 seconds, what with water tending to destroy common refractory materials at high temperature.

    Now, if there is ammonia or methanol in the ice, those components could make effective propellants for nuclear thermal rockets. As I recall, an Isp of 600 seconds is possible with ammonia.

  15. Paul, I put a little more detail behind it on my blog. Supposedly, 100 seconds Isp is possible with liquid water at around 200 atmospheres.

    Ah, I think I see the issue – this is not a high-temperature steam rocket, this is a low temperature water rocket powered by steam. (As in, most of what exits the nozzle is liquid.)

    A little silly, but dead simple.

  16. David,

    It strikes me one of the advantages of a steam rocket is that most of the propellant will stay in the lunar gravity field, which means it should migrate back to one of the polar heat sinks eventually. In short, it would basically allow a major portion of the water to be recycled as fuel over and over… The only question would be the time scales involved.

    Tom

  17. And you really need to ask what you want to utilize it for.. is it for supplying some lunar base, like drinking water and oxygen? Or is it for launching to L2 to make propellant to reduce the size of launch vehicles required to explore the solar system?

    First come, first served.

  18. Thomas, exactly – if we use the water as propellant in the lunar vicinity, it eventually vaporizes, wanders the moon for a while, and then ends up in a cold trap. Some portion will end up above escape velocity, but at least some will not. (Steam or liquid doesn’t matter – water does not stay liquid in a vacuum.)

  19. ask what you want to utilize it for..

    Karl: First come, first served.

    Without a property rights regime, there will be no incentive to recycle or conserve the water for later, better uses — it will be frittered away quickly.

  20. Bill White said “With water at both poles, the leverage offered by an EML transfer station and reusable lunar landers only increases.”

    Am I right to think it doesn’t matter that the water is at both poles? If the discovery had been that there was more water at the South pole, would that be just as good? In terms of orbital mechanics with an EML transfer station, etc, is there actually an advantage to having water at the North pole as well?

  21. Bob-1,

    If there are multiple interesting places on the Moon (and there are) then global lunar access becomes very valuable, almost necessary.

    EML staging offers 24/7 global lunar access and a place to park reusable lunar landers between missions.

    An EML depot also provides a central node for fuel depots supplied with water from various locations on the lunar surface as we do not yet know which craters will offer easiest “extractability” for actually harvesting lunar ISRU water.

    EML staging could also support multiple sortie missions to “check out” craters at various locations.

  22. I understand the advantages of a depot at EM-L1 (or EM-L2 for interplanetary jump-offs).

    I was just wondering whether there was any advantage to having ice (which will ultimately get stored in one form or another at an EML depot) available at both poles as opposed to just the South pole.

  23. If the ice has been sitting there, being irradiated, for millions of years, it might have a good fraction of hydrogen peroxide in it by now (or even free radicals, if it’s as cold as 25 K). I’d worry a bit about the stuff exploding when processed, particularly if it has peroxide + organic materials.

    On the plus side, hydrogen peroxide would make a dandy monopropellant or oxidizer for lunar launch vehicles.

  24. Bob-1 says: I was just wondering whether there was any advantage to having ice (which will ultimately get stored in one form or another at an EML depot) available at both poles as opposed to just the South pole.

    I didn’t intend to imply more than the idea that multiple valuable lunar destinations strengthens the case for EML architectures. I did not intend to assert any specific advantage of north pole versus south pole.

    However, if there are many craters with ice, that should simply property rights issues and geopolitical issues. If there are additional perfectly good ice craters left untouched then China has less to complain about if US interests begin mining one of them.

    Peaks of eternal sunlight – being very scarce – do provide a flash point for conflict.

  25. Rand,

    The last thing needed now is a call for lunar property rights. Mining firms made that mistake in the 1960’s by trying to claim portions of the sea floor. The resulting Law of the Sea Conferences killed deep ocean mining.

    The legal regime that is in place for lunar resources at the moment, if you pick it up its yours, is well suited to lunar industrial development. More restrictive laws should wait until a future “Lunar Republic” declares independence and creates its own laws for land ownership.

  26. Paul Spudis:
    If the ice has been sitting there, being irradiated, for millions of years,…

    Does it matter if the radiation was GCRs rather than (direct) solar photons or solar wind?

  27. Does it matter if the radiation was GCRs rather than (direct) solar photons or solar wind?

    That was not Paul Spudis who wrote that.

  28. Yes, I was talking about what NASA should do with that ice, if they actually had any real interest in expanding humanity into the solar system. But if you prefer, we can talk about what the next prize after the GLXP should be if it actually gets won. Sample return? ISRU?

  29. Trent:
    what NASA should do with that ice

    NASA should be forbidden from doing anything with it except conducting tests. Since when did we become a socialist country with government owning economic assets?

    what the next prize after the GLXP should be if it actually gets won. Sample return? ISRU?

    ISRU simulations on earth are easier than even GLXP and can and should be done today. For example, give a $1 million prize for somebody to start with a 100 kg block of water ice, process it into a block of propellant, and launch. The propellant can be anything the contestant wants as long as it originated from the ice. (e.g. it could be a thermal water “steam” rocket, a thermal hydrogen rocket discarding the O2, an LH/LOX rocket, etc.). All propellants not derived from the ice are forbidden. The clock starts when they start processing the block of ice. The first team to process the propellant, fuel their rocket, to launch it to, say, 1 km after the clock starts ticking wins the prize. So it’s basically a race to produce rocket propellant and then fuel and launch a decent rocket.

    Alternatively, one could run a rocket race (whatever happened to the Rocket Racing League?) where the rules are that the contestants must make all the propellant they use from water.

    (As we better characterize the contents of actual lunar ice — e.g. does it contain methane? hydrogen peroxide? etc. the contest can be modified and rerun with improved ice simulant instead of pure water).

    We could have an ice harvesting robot contest, where contestants have small robots (100 kg weight limit) traverse muddy stretch of glaciers to extract and purify the ice (by whatever means the contestants like, but all energy production and machinery is part of that 100 kg budget). Whoever produces the most 99% pure water out of the frozen mud in the space of two hours wins.

    With a higher budget of $10 million, spend $5 million to build a lunar polar crater environmental simulator, then offer a $5 million prize to the machine that can extract and clean the most ice inside that simulator. Another idea along these lines — the Unviersity Washington has a Mars atmosphere simulator. The prize could be awarded to whoever makes the most rocket propellant from the simulated Martian atmosphere. Part of the fund goes to renting (and if necessary improving) the simulator for running the contest and part goes towards the prize.

  30. googaw, I’d suggest that you’re an ignorant man but I don’t know that you’re male. There’s so much stupidity in what you just posted that I don’t even know where to begin.. so I’ll just say that the Rocket Racing League will be holding its next show on April 24th at the Tulsa International Airport, and leave the rest up to you to figure out.

  31. Ouch, Trent seems somewhere along the line to have taken offense at my exposing him to some reality. Don’t like the news, chop off the head of the messenger.

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