I see how if the H2 is implanted in the regolith, heating would release it.

As far as dissociation into hydrogen and oxygen, that temperature seems low. I’ve only looked at hydrolysis in the past. A quick Goggle showed me one site discussing dissociation at 2500K while another mentioned splitting some hydroxide ions at varied temperatures and pressures. I’d be curious to know the process. If you have a specific reference, please email it to me or post it here.

IF the hydrogen is in the regolith as H2O or implanted hydrogen, simple heating to 700 degrees C will liberate all of the gas.

If it is bound in hydrocarbons, which is entirely possible, then it opens up other interesting uses on the Moon. Carbon is just as valuable as hydrogen as it can be used in the carbothermal process for oxygen production and when burned with lunar oxygen it does release the hydrogen to water, where it is easily separated, creating CO2 in the process, which is also easily seperable or used to grow food.

In all likelyhood the hydrogen is in all of the above forms as it is derived from cometary impacts as well as hydrogen implantation from the Sun.

it will be interesting to see the list of things we “can’t live without” this time when we go to the moon

If we allow it to, as was allowed in the once quick-and-dirty VSE, this list will expand to some large number multiplied by the number of NASA centers. Fortunately, there are other peoples in the world and an ever larger number of them will eventually become capable of human spaceflight. Already, at least one of the newcomers (China) is ignoring American equipment and adapting relatively unsophisticated but cheap Russian designs.

— Donald

— Donald

Hydrogen may or may not be better than methane. If water is found, it probably is. However, separating hydrogen from regolith, because of its scarcity per unit volume, sounds like much more of a challenge for an early base than separating oxygen. And, it’s light, so it may be easier to carry to the moon (although, as Tom mentions, the storage requirements are high).

One key advantage of methane is that carbon is widely available in the inner Solar System — on Mars, asteroids, Venus’ upper atmosphere. If you are going to use one rocket at multiple destinations, methane may make sense. Also, I’ve never heard Tom’s suggestion of using human waste products as a feed source for methane (no irony intended), and that idea seems worth exploring.

My bottom like is that whatever we use, it needs to be burnt with raw oxygen to make it possible to get an early start on extracting a key — and the heaviest — resource we are likely to need in any quantity.

Anonymous: We’re obviously not going to send astronauts to do landing site remote sensing from Mars orbit. [Apollo did.] We’re obviously not going to send astronauts to Mars to test the chemical toxicity of Martian dust. [Apollo did, when a lot less was known about lunar dust than is known today about Martian dust.] We’re obviously not going to send astronauts to Mars to test a precision landing system, [Apollo did.] especially if the astronauts need that system to reach their habitat, power, supplies, etc. And we’re obviously not going to send astronauts to Mars watch a methane production unit function for months on end, especially if they’re dependent on that methane for the trip back home.

Well, all of those may be obvious. But, if we’re not willing to do some risky things and let astronauts tinker things into working, we will not be going to Mars in our lifetimes, and maybe not ever. It is hard to imagine any political and economic scenario where Mars missions will be done any other way than the cheapest possible, particularly if another, less wasteful nation is the first to attempt it. Remember that all of these test missions, while each one may be relatively inexpensive, are collectively a lot money on top of the minimum required to send astronauts to Mars. True, some of them may reduce long-term costs. But a politically and economically far more likely scenario in my mind is for someone to do this on a shoestring, or less likely as a time-constrained crash project similar to Apollo, and work on sustainability and greater safety after the first attempts succeed — if they succeed.

— Donald

Compared to methane, hydrogen has higher Isp, but it takes a lot more storage space, has a much lower liquefaction temperature, and since it’s likely found bound to oxygen in the lunar regolith, it will take a lot of energy to separate. Assuming the oxygen and hydrogen are both produced at the moon, a craft could land ‘empty’ and be completely loaded with propellants

Methane is denser, liquefies at a higher temperature (than even O2), and can be produced on Mars at a lower energy cost than hydrogen. Being at the bottom of the moon’s gravity well argues for denser propellants, but I’m not sure where the tradeoff works best. Since methane can’t easily be produced on the moon (other than by using CO2 exhaled by the crew of a base), the craft would have to land with methane on board and tank up with LOX.

Either hydrogen or methane could work on the moon, but methane would be easier to do on Mars. Both have higher performance than storables. More specific statements would depend on the trade space.

I’m sure I’ll be corrected if I missed anything.

And it’s superior to hydrogen (which unlike methane, is actually available on the moon) in those regards how?

“Speaking of politics, reader Armin Ellis passes along this item:
John McCain’s vision for space exploration

Today John McCain was at Dartmouth College on a final rally before the primaries in the Granite state There I had the opportunity to ask him this question: ‘Senator, what is your vision for America’s space program?’ Having just answered a tough question from another individual he appeared to be taken aback, as though this was the sort of question for which he had an answer but was looking for the words which would completely represent the extent of his thoughts.

He replied ‘Sure’ then paused, ‘whats my vision?’ he asked as though trying to clarify my question ‘…go to Mars. Yeah…’ Feeling confident of this answer, he moved on to the next question.”

Unfortunately, there’s nothing else after the “Yeah…”.

FWIW…