Propellant Depots have lots of issues that will need to be addressed before it is viable and ready. I eventually see a marriage of HLV + propellant depots at some point, unless some other type of propulsion system comes to the front of the pack.
With effective design, analysis indicates that total system boil-off can be held to 0.01 percent per day...
I understand how the spacecraft would rendezvous with the depot, but is the depot likely to be in the required orbit for the spacecraft to then undertake it's insertion burn?
A lunar lander that can spend weeks or months on the moon is not likely to be fueled by lox\loh .
Quote from: pathfinder_01 on 08/06/2010 03:09 pm A lunar lander that can spend weeks or months on the moon is not likely to be fueled by loxloh . Liquid hydrogen liquid oxygen propellants may be perfectly feasible if the lander is landing at location that is permanently shaded and has ice... Propellant tankers going to and from an EML1 or 2 propellant depot to the permanently shaded Lunar locations would most likely use liquid hydrogen and liquid oxygen propellants.Cheers!Edited.
A lunar lander that can spend weeks or months on the moon is not likely to be fueled by loxloh .
Or landed *anywhere* and then parked in the shade. It will stay just s cold.
Quote from: HappyMartian on 08/08/2010 01:12 amQuote from: pathfinder_01 on 08/06/2010 03:09 pm A lunar lander that can spend weeks or months on the moon is not likely to be fueled by loxloh . Liquid hydrogen liquid oxygen propellants may be perfectly feasible if the lander is landing at location that is permanently shaded and has ice... Propellant tankers going to and from an EML1 or 2 propellant depot to the permanently shaded Lunar locations would most likely use liquid hydrogen and liquid oxygen propellants.Cheers!Edited.Or landed *anywhere* and then parked in the shade. It will stay just s cold.
Would a LSAM in left to loiter in Lunar orbit for several months not demonstrate the ability to minimize boil-off just as well as a "depot demonstrator?" It seems like possibly a good 2 for 1 deal.
Are prop depots at least welcomed in both the Senate and House bill?
Quote from: Mr. Justice on 08/13/2010 12:57 amWould a LSAM in left to loiter in Lunar orbit for several months not demonstrate the ability to minimize boil-off just as well as a "depot demonstrator?" It seems like possibly a good 2 for 1 deal. Boiloff is only half of it. Need to demonstrate propellant transfer as well. Simply parking the LSAM would not demonstrate that.
Quote from: Jorge on 08/13/2010 01:31 amQuote from: Mr. Justice on 08/13/2010 12:57 amWould a LSAM in left to loiter in Lunar orbit for several months not demonstrate the ability to minimize boil-off just as well as a "depot demonstrator?" It seems like possibly a good 2 for 1 deal. Boiloff is only half of it. Need to demonstrate propellant transfer as well. Simply parking the LSAM would not demonstrate that.Hasn't that been proven with the ISS, MIR and on other occasions.
Quote from: Mr. Justice on 08/13/2010 01:38 amQuote from: Jorge on 08/13/2010 01:31 amQuote from: Mr. Justice on 08/13/2010 12:57 amWould a LSAM in left to loiter in Lunar orbit for several months not demonstrate the ability to minimize boil-off just as well as a "depot demonstrator?" It seems like possibly a good 2 for 1 deal. Boiloff is only half of it. Need to demonstrate propellant transfer as well. Simply parking the LSAM would not demonstrate that.Hasn't that been proven with the ISS, MIR and on other occasions. No, that's hypergolic propellants. The whole point here is cryogenic propellants (otherwise, would controlling boiloff even be an objective?). That has never been demonstrated.
Quote from: Jorge on 08/13/2010 01:45 amQuote from: Mr. Justice on 08/13/2010 01:38 amQuote from: Jorge on 08/13/2010 01:31 amQuote from: Mr. Justice on 08/13/2010 12:57 amWould a LSAM in left to loiter in Lunar orbit for several months not demonstrate the ability to minimize boil-off just as well as a "depot demonstrator?" It seems like possibly a good 2 for 1 deal. Boiloff is only half of it. Need to demonstrate propellant transfer as well. Simply parking the LSAM would not demonstrate that.Hasn't that been proven with the ISS, MIR and on other occasions. No, that's hypergolic propellants. The whole point here is cryogenic propellants (otherwise, would controlling boiloff even be an objective?). That has never been demonstrated.Wouldn't the actual transfer mechanism be the same? To be honest, I don't know how it is done today on the ISS.
Quote from: DavisSTS on 08/11/2010 12:11 pmAre prop depots at least welcomed in both the Senate and House bill?The House bill does not provide enough funding for one.The Senate bill does provide funding for flagship technology demonstrators but leaves which demonstrators up to NASA.