Let me explain further - if the near term objective is the creation of a self sustain local orbital capability on the moon, ie a vehicle that could land on the surface with empty propellant tanks, be refueled on the surface, and then attain lunar orbit and subsequent descent back to a propellant base, then we could probably attain that objective using payloads sent to the moon with a mass of less than 13 tons per payload, using current technologies, at much lower cost than the Exploration program plans.Ironically, the Ares I-X launcher may be practical under such an architecture.
Quote from: Danderman on 11/17/2009 12:38 amLet me explain further - if the near term objective is the creation of a self sustain local orbital capability on the moon, ie a vehicle that could land on the surface with empty propellant tanks, be refueled on the surface, and then attain lunar orbit and subsequent descent back to a propellant base, then we could probably attain that objective using payloads sent to the moon with a mass of less than 13 tons per payload, using current technologies, at much lower cost than the Exploration program plans.Ironically, the Ares I-X launcher may be practical under such an architecture.Just how much ice would need to be processed to supply the propellant needed for one round trip ?Mick.
Just how much ice would need to be processed to supply the propellant needed for one round trip ?
Assuming the icey regolith water content is 1%, that means processing almost 300 tons of regolith per day. But it may be as high as 4%.
So if you want to move 200 tons per year from L2 to the Moon, and put 200 tons of fuel and/or water in an L2 depot, all using lunar ISRU propellant, you need to extract a little under 3 tons of water per day.
Quote from: kkattula on 11/17/2009 06:53 amAssuming the icey regolith water content is 1%, that means processing almost 300 tons of regolith per day. But it may be as high as 4%.Once again, the above comment ignores the Clementine and Lunar Prospector data. Clementine discovered large area with a reflective equivalent of water ice; Prospector found vast amounts of hydrogen in the same general area. Just because NASA claimed to find on 24 kg of water in the plume does not mean that there aren't sheets of ice in that crater. The mechanism of transporting water in an impact plume is not well known.
Also, the colder temperatures could allow for ammonia ice to be preserved at the lunar South Pole. And finding a big ball of ammonia ice would be very interesting.
I was fortunate enough to spend a day and a half at the ongoing LEAG conference. Unfortunately, I had to leave early.In any event, the Lunar Reconnaissance Orbiter is returning marvelous data from the lunar South Pole (beyond LCROSS) -- data which has only begun to be analyzed....But for now, getting good mobile robots onto the lunar South Pole would seem to be Job #1. At least IMHO.= = =Also, the colder temperatures could allow for ammonia ice to be preserved at the lunar South Pole. And finding a big ball of ammonia ice would be very interesting.
Your magic machine, (which wouldn't be magic, just a matter of engineering), would have considerable mass, as would the equipment to gather the regolith (or even relatively pure ice).Up to a certain number of missions, it would be more mass efficient to pre-land expendable tankers with the propellant to refuel the lander. Above that number it would be more efficient to send the ISRU equipment and make the propellant.You'll actually need more than half of the 12 tons on the surface to be fuel. Without picking up any cargo in lunar orbit, and without any landing reserve, it would need to be almost 7 out of 12 tons.Assuming the supplies picked up in lunar orbit are equal in mass to the empty lander, approximately 2/3 of the launch mass from the surface would have to be fuel. So starting on the Moon with 4 tons of empty lander & 8 tons of fuel, lands 4 tons of cargo.
The japanese pay huge money for imported ice with special properties. It would, indeed, be a luxury for some ultra-expensive product to be made using lunar ice....
Quote from: Downix on 11/18/2009 05:10 pmThe japanese pay huge money for imported ice with special properties. It would, indeed, be a luxury for some ultra-expensive product to be made using lunar ice....Some of those examples include Evian-lunar & Moonbucks...posts I had seen on a CBC blog.