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Sounds basically feasible, though real development work would have to be done before it would be possible to comment on whether the engineering would actually work out. The one thing that I'm not comfortable with is where you're going to get the oxygen from. It's probably not frozen in the craters, and electrolyzing your way to it would be difficult. I suppose you could use a TiO2 catalyst to photodissociate water in open sunlight, but that will only be about 6% efficient and possibly mass-intensive.
Heat up the regolith until it starts breaking up into oxygen gas and a metal slag? The unit to do that might be heavy, but one can theoretically use direct solar heating to get it done, and one of the 'waste' products is iron.
Hey ARD, welcome to Newmars!
Falcon Heavy has a payload of 53 tonnes to LEO. The delta V from LEO to the Moon is about 6.3 km/s, with a bit (~400 m/s) of margin to account for the fact that you're not going to the lunar equator and for a bit extra for attitude control while landing. With an Isp of 450 s, this would be a mass ratio of 4.36 (Are you familiar with the rocket equation?). That is a payload of 12,700 kg to the Moon. However, some of this will be taken up with fuel tanks and the like. Assuming a centaur-like ratio of fuel mass to dry mass, which is about 10:1, 4000 kg of this will be used up with rocket structure. Therefore, the payload to the lunar surface would be 8,700 kg.
Thank you for the welcome.
I am familiar with the rocket equation, but I was unsure about how much delta-v would be necessary for a lunar polar mission as opposed to an equatorial one.
So, 8.7 metric tons. Enough for Sundancer, or for a Dragon to serve as the logistics vehicle for each manned mission. Of course, we'll want a somewhat cheaper and smaller unmanned logistics vehicle to do most of that work, but in the Early Lunar Access-derivative I suggest, we could possibly reduce the total number of lunar landings per expedition to just one per launch, so we have the following architecture:
Falcon Heavy 1: Deploy Sundancer
Falcon Heavy 2: Deploy first equipment lander--rovers, scientific equipment, a bigger set of solar panels, stuff to outfit Sundancer with, the like. Pre-position methane/oxygen propellant for return trip.
Falcon Heavy 3: Deploy first crew (original ELA called for two, but I think we can do three) for 3-week expedition. They set up the Sundancer and do a geological survey. Refuel their lander with CH4/LOX (we'll need a hydrogen/oxygen engine that can reliably burn methane).
Falcon Heavy 4: Start landing basic ISRU equipment--stuff to cut the ice out of the craters. Given what we currently know of the Moon, water ice is far from the only thing we'll find--methane, methanol, and probably ammonia are up there too.
This is just the rudiments of a plan, I fear, but I'd like to know how plausible this is. But if at least the first few landings can be done for an Elon Musk-size fortune, and this thing can get some sort of government contract ($200 million per US Astronaut or Russian Cosmonaut on board), then this could just work out.
And, of course, if SpaceX gets that fully-reusable-Falcon-9 up by the end of the decade, it might even become a viable business!
How about we start out with a Dragon on an Early Lunar Access-type system? That system would have relied on using Titan IV or Ariane 5 with the STS to put 8.5 metric tons of payload on the lunar surface at a time. Three of those 8.5 ton payloads would have been used to two crewmembers on the lunar surface for a three week period. Could we substitute Dragon for the Apollo CM, put a Centaur on top of the Falcon Heavy, and put a landing stage on top of that? How much payload can Falcon Heavy and that hypothetical hydrogen-oxygen landing stage (assume specific impulse of 450 seconds) put at the lunar North Pole?
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