According to this answer to what the moon is made of, the moon's crust is, among other things, 43% oxygen.

Assuming we were to go back to the moon within the next couple of years with the goal of establishing a long-term presence (read: base/colony), would we be able to process the crust and extract that oxygen to let our astronauts breathe without having to bring all of the atmosphere they'd otherwise need along on the journey?

More to the point, is it worth it to bring the equipment needed to extract oxygen out of the moon's crust, or would it be easier/more cost effective to just fly in a bunch of air in compressed tanks?

Note: Obviously oxygen isn't all we need, as Apollo 1 tragically proved, but if we can get even a part of the air needed to fill a base with as we build it, that could save considerable mass (and, thus, cost) needed to be brought in -- unless the equipment necessary weighs more and/or is more costly to operate, of course.

  • $\begingroup$ Huh. now -this- is a question. I can't even guess, but I'll be fascinated to know what the answer is. $\endgroup$
    – Rowanas
    Oct 24, 2014 at 16:10
  • 1
    $\begingroup$ While this question might be on topic here, it might be better suited to Space Exploration SE. $\endgroup$ Oct 24, 2014 at 16:33

3 Answers 3


At least the Artemis project thinks it is possible.

The process they describe is $$\rm FeTiO_3 + H_2 \to Fe + TiO_2 + H_2O$$ and then split the water to hydrogen and oxygen (note that after splitting the same amount of hydrogen is resumed as is put in at the beginning, so apart from replacing losses, you don't consume hydrogen in the process). Interestingly, at the same time it produces iron. Also, if you are willing to actually consume hydrogen, you also get water (another valuable substance). Note that they also plan to get the hydrogen from the moon

Also NASA plans to generate oxygen/water from the moon crust. So apparently the science behind it is sound.

  • $\begingroup$ Artemis goes on to say it's "...a system we could design to be the size of a briefcase" -- so that answers the portability/cost effectiveness half of it. I'm not surprised it's doable, but I am surprised it's that compact a system to do it with!! $\endgroup$
    – Kromey
    Oct 24, 2014 at 18:09
  • $\begingroup$ Is there a reasonable Hydrogen source on the moon? I understand it is an intermediate but there will be some material loss and any water that is produced would consume hydrogen. Actually, nevermind, as hydrogen in atmosphere might be easier to separate out that other gases despite the tiny pressure. $\endgroup$
    – kaine
    Oct 24, 2014 at 20:07
  • $\begingroup$ @kaine The Moon's atmosphere, which has a surface pressure on the order of $10^{-15}$ times that of Earth's, contains helium-4, which might be usable (break it in half; I don't know what's involved in doing that). en.wikipedia.org/wiki/Moon#Atmosphere There is also water vapor at certain latitudes and helium is mentioned as present in the regolith. So you probably could with some effort kickstart the process, as well as reasonably easily keep it running once you've got it going. $\endgroup$
    – user
    Oct 25, 2014 at 20:49
  • $\begingroup$ @Micheal Kjorling the water vapor isnt very common but wouldnt hurt. That pressure definitely is a limiting factor. What is the helium for? $\endgroup$
    – kaine
    Oct 25, 2014 at 20:55
  • $\begingroup$ @kaine: From the Artemis site: "But to get it started with an initial supply of hydrogen, we need only heat the raw regolith to about 600 degrees C. That will drive off hydrogen (along with a host of other interesting gasses, such as helium) that we use to reduce the first load of lunar soil." $\endgroup$
    – celtschk
    Oct 26, 2014 at 5:44

Lay out enough mirrors, you can produce enough heat to crack any molecule.

Note, however, that for a truly long term answer you don't need oxygen. We breathe oxygen and eat food, we exhale carbon dioxide as a result. Plants breathe carbon dioxide, produce food and exhale oxygen. Assuming the food supply is balanced the oxygen supply must inherently also balance. Thus if you are producing your own food you're producing your own oxygen.

  • $\begingroup$ But you need to bring either the O2 or the CO2 with you under that scenario. If you can mine the O2 (or the CO2, for that matter) after you get there, that's less mass you have to bring in the first place. $\endgroup$
    – Kromey
    Oct 25, 2014 at 2:34
  • $\begingroup$ @Kromey It comes down to whether the cracker or the oxygen is heavier. If the process celtschk refers to works it's obvious the cracker is lighter if you have enough power (his device obviously don't contain it's power source.) $\endgroup$ Oct 25, 2014 at 2:50
  • $\begingroup$ The device described by the Artemis Project uses solar reflectors for heat and photovoltaic panels for electricity, both of which do seem to be included. $\endgroup$
    – Kromey
    Oct 25, 2014 at 7:07
  • $\begingroup$ @Kromey In something the size of a briefcase??? $\endgroup$ Oct 25, 2014 at 22:51
  • $\begingroup$ The Project Artemis people seem to think so. Even if not, though, that's not going to add a huge amount of excess bulk anyway. $\endgroup$
    – Kromey
    Oct 26, 2014 at 6:36

There's a great book on asteroid mining that talks about all of the chemical conversion processes (including making air) that could be employed on the Moon, Mars, or the asteroids. It's called "Mining the Sky" by John S. Lewis. Available on Amazon.

  • 2
    $\begingroup$ This is a link-only answer; answers like these are normally frowned upon. Is there any way you could expand on it, though? Maybe elaborate on the processes? $\endgroup$
    – HDE 226868
    Oct 26, 2014 at 0:24
  • $\begingroup$ Understood. The catch is that the book looks at the whole system (of human settlement) not just a chemical equation. Thus it would take pages to explain and I'd be doing little more than copying and pasting. If you want to take this answer down I understand. $\endgroup$
    – Tom
    Oct 26, 2014 at 0:25
  • $\begingroup$ I wouldn't vote to take it down because I still think there's a chance it could be expanded upon. It's up to you as to what you want to do here. $\endgroup$
    – HDE 226868
    Oct 26, 2014 at 0:29
  • $\begingroup$ It might be better as a comment, unless it's expanded into an answer ( cc @HDE226868 ) $\endgroup$
    – Shokhet
    Oct 28, 2014 at 4:37

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