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This implies a fuel mining and refinery process that is off-planet. Otherwise, you have to launch the fuel, and that is an extremely expensive prospect. If a

by bdamm 13y ago

This implies a fuel mining and refinery process that is off-planet. Otherwise, you have to launch the fuel, and that is an extremely expensive prospect. If a mission is going to be engineered to operate for a long period of time, you'd either launch the mission with all the fuel it needs or plan refueling launches specifically for that mission, as is done with the ISS. So, who will be the first to mine off-world and refine into usable rocket fuel? This seems pretty far off considering the exotic materials needed for rocket fuel, like hydrazine. I think it's too far out to make a reasonable bet on who will provide the first in-orbit refueling station.

ChuckMcM 13y ago
Actually not at all. It implies you can send cost reduced rockets up with tanks filled with cryogenic fuels (LH/LOX), if you lose them their cost is amortized over all the expensive rockets you didn't have to send up with a full fuel load. One of the most interesting talks at the AMW conference one year was ULA talking about cryogenic fuel depots [1]. Not Hydrazine, these are not hypergolic fuels just "regular" liquid oxygen and hydrogen. The change in the cost dynamics is quite compelling though. Consider a 'space tug' which is in orbit and only needs fuel to meet up with a satellite, and move it into any orbit (supply the 'delta V' as it were). Now launching a satellite doesn't have 'launch windows' nor is it constrained by geography. Costs go down, response rate goes up. Going to the moon and back? No need to launch all the fuel you need. A vehicle that 'lives' in orbit can take your service module/lunar module and put it on a trans-lunar injection orbit with enough gas to land and return. Catch you on the return and put you in an orbit ready for re-entry. [1] http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CDcQFjAB&url=http%3A%2F%2Fselenianboondocks.com%2Fwp-content%2Fuploads%2F2008%2F11%2F2008-7644-depot-document.pdf&ei=tH9EUuH8FcvriwL75IHgDA&usg=AFQjCNG6lMLp2QNL7AeeVkDtTMj5YWHoYA&bvm=bv.53217764,d.cGE&cad=rja http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd...

by bdamm 13y ago

ChuckMcM 13y ago

Actually not at all. It implies you can send cost reduced rockets up with tanks filled with cryogenic fuels (LH/LOX), if you lose them their cost is amortized over all the expensive rockets you didn't have to send up with a full fuel load. One of the most interesting talks at the AMW conference one year was ULA talking about cryogenic fuel depots [1]. Not Hydrazine, these are not hypergolic fuels just "regular" liquid oxygen and hydrogen. The change in the cost dynamics is quite compelling though. Consider a 'space tug' which is in orbit and only needs fuel to meet up with a satellite, and move it into any orbit (supply the 'delta V' as it were). Now launching a satellite doesn't have 'launch windows' nor is it constrained by geography. Costs go down, response rate goes up. Going to the moon and back? No need to launch all the fuel you need. A vehicle that 'lives' in orbit can take your service module/lunar module and put it on a trans-lunar injection orbit with enough gas to land and return. Catch you on the return and put you in an orbit ready for re-entry. [1] http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CDcQFjAB&url=http%3A%2F%2Fselenianboondocks.com%2Fwp-content%2Fuploads%2F2008%2F11%2F2008-7644-depot-document.pdf&ei=tH9EUuH8FcvriwL75IHgDA&usg=AFQjCNG6lMLp2QNL7AeeVkDtTMj5YWHoYA&bvm=bv.53217764,d.cGE&cad=rja http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd...