JohnHunt
05-14-2010, 08:18 AM
One of the major arguments for The Case for Mars as opposed to returning to the moon is that Mars contains large quantities of readily available volatiles whereas the moon largely lacks these.
Well, as we are now learning, this is less of an issue than was previously thought. We now know that there are significant quantities of water towards the lunar poles. Unfortunately, the concentration seems to still be pretty low (perhaps 200 ppm?) as opposed to about 50 ppm in the regolith of other parts of the moon. And this seems to hold true for all of the critical volatiles in that the concentration of carbon is about 50ppm and the concentration of nitrogen is about 50 ppm.
IS EXTRACTION OF VOLATILES FROM THE REGOLITH FEASIBLE?
50 ppm = 5/1,000 of 1%. That's pretty small. To extact just 1 kg of a particular volatile you would have to process 20,000 kg of regolith by heating it to 700 C. It's doable but a lot of work.
COULD WE JUST SUPPLY A LUNAR OUTPOST
Instead of going through all of the work extracting volatiles from the regolith, might it be better to just ship it to the lunar surface?
Using an Aquarius launch system volatiles could be delivered to LEO at about $600/kg. I don't know but let's say that we use a space tug and reusable cis-lunar transport and lunar lander it would cost about $2,000/kg to deliver that to the lunar surface. At least in theory.
But how much would be needed by a lunar outpost? I've done some napkin calculations using the acreage of Biosphere II and the average amount of carbon per square acre of forest. By my calculations, one could deliver enough carbon or nitrogen with between one or two Altair lander-sized cargo deliveries.
But Biosphere II was overbuilt for our purposes. For example it had 5 biomes. Rather, we would probably use high tech equipment, intensive farming, and otherwise closed systems and recycle the volatiles.
Also, we wouldn't need to ship water to the moon. We only would need to deliver the relatively low mass hydrogen part of water (perhaps in the form of amonia?). Since oxygen is extremely abundant on the lunar surface one should be able to create water relatively easily.
So all told, we could probably deliver enough volatiles for a basic, self-sustaining lunar outpost with, I'm guessing, a couple of Altair sized cargo landers or 10 or so medium-sized cargo landers.
Using the Aquarius and SpaceX numbers this would cost between $30 and $800 million. Both well within NASA budgets.
Well, as we are now learning, this is less of an issue than was previously thought. We now know that there are significant quantities of water towards the lunar poles. Unfortunately, the concentration seems to still be pretty low (perhaps 200 ppm?) as opposed to about 50 ppm in the regolith of other parts of the moon. And this seems to hold true for all of the critical volatiles in that the concentration of carbon is about 50ppm and the concentration of nitrogen is about 50 ppm.
IS EXTRACTION OF VOLATILES FROM THE REGOLITH FEASIBLE?
50 ppm = 5/1,000 of 1%. That's pretty small. To extact just 1 kg of a particular volatile you would have to process 20,000 kg of regolith by heating it to 700 C. It's doable but a lot of work.
COULD WE JUST SUPPLY A LUNAR OUTPOST
Instead of going through all of the work extracting volatiles from the regolith, might it be better to just ship it to the lunar surface?
Using an Aquarius launch system volatiles could be delivered to LEO at about $600/kg. I don't know but let's say that we use a space tug and reusable cis-lunar transport and lunar lander it would cost about $2,000/kg to deliver that to the lunar surface. At least in theory.
But how much would be needed by a lunar outpost? I've done some napkin calculations using the acreage of Biosphere II and the average amount of carbon per square acre of forest. By my calculations, one could deliver enough carbon or nitrogen with between one or two Altair lander-sized cargo deliveries.
But Biosphere II was overbuilt for our purposes. For example it had 5 biomes. Rather, we would probably use high tech equipment, intensive farming, and otherwise closed systems and recycle the volatiles.
Also, we wouldn't need to ship water to the moon. We only would need to deliver the relatively low mass hydrogen part of water (perhaps in the form of amonia?). Since oxygen is extremely abundant on the lunar surface one should be able to create water relatively easily.
So all told, we could probably deliver enough volatiles for a basic, self-sustaining lunar outpost with, I'm guessing, a couple of Altair sized cargo landers or 10 or so medium-sized cargo landers.
Using the Aquarius and SpaceX numbers this would cost between $30 and $800 million. Both well within NASA budgets.