Moon rocks and a bit of math
Ran across a copy/article on extracting oxygen from moon rocks. The interesting bit:
New Device Extracts Oxygen from Moon Rocks | Universe Today Fray anticipates that three reactors, each a meter high, would be enough to generate a ton of oxygen per year on the Moon. Three tons of rock are needed to produce a ton of oxygen, and in tests the team saw almost 100% recovery of oxygen, he says.
The comments got the math badly wrong. Poking around the web I got some rough numbers:
- ~0.25 liters / minute - oxygen consumed for human at rest.
- ~5 liters / minute - oxygen consumed for athlete / heavy exercise.
- ~1.43 grams / liter - oxygen gas at Earth sea level pressure.
Barring any dumb math errors on my part, that translates to....
- ~636,000 liters / year - the ton of oxygen produced by the above-mentioned generator.
- ~131,500 liters / year - oxygen consumed by a person at rest.
- ~4.8 person-at-rest-years of oxygen generated every year.
Assuming that a "real" space habitat would also have the means to recycle oxygen from exhaled CO^2^, that is a lot of oxygen!
What is the real need for that much oxygen? Outside use as rocket fuel (or other manufacturing process), the main need would be to supply air for expanded living space. Assuming ~3 meter ceilings, we need ~3000 liters air for each square meter of living space. So one generator would allow expanding the living space by ~2000 square meters / year.
Not bad. And that is just one reactor (and essentially a prototype, at that).
Only one part of the equation (for habitat supply needs), of course. For practical purpose, would be nice to also have some nitrogen in the air. Not sure where that would come from. Do any moon rocks contain nitrogen? Water is also needed. Barring any fortunate discovery of water on the moon, we could synthesize water given a source of hydrogen. Do any moon rocks contain hydrogen?