Jorge - 23/1/2008 1:04 PMThis needs to be merged with the other thread...
Yegor - 23/1/2008 7:57 PMIf to switch to DIRECT.Will it be possible to develop a hydrogen LEO storage solution for 15 billion savings on Ares I and Ares V development plus 900 million a year on operations?
jongoff - 24/1/2008 3:20 PMQuoteYegor - 23/1/2008 7:57 PMIf to switch to DIRECT.Will it be possible to develop a hydrogen LEO storage solution for 15 billion savings on Ares I and Ares V development plus 900 million a year on operations?Yes. Quite frankly, NASA could get that capability for less than $1B if they could find a way to put that money in escrow to purchase the first 100,000 of LOX/LH2 from a commercial depot.~jon
As I understand it. Liquid Oxygen would be by far the largest component by mass of any non-nuclear Mars mission. A far easier depot problem. Liquid Hydrogen would be the largest volume, but one Ares V or Jupiter 232 would suffice to launch that mass: < 80 mt
SMetch - 23/1/2008 12:45 PMI hope we’re smart enough that we never again try to place such a large system in orbit by doing it in twenty-ton chunks. I think we all understand that fewer launches of larger payloads requiring less on-orbit integration are to be preferred. Thus, a vehicle in the Saturn V class –some 300,000 lbs in LEO – allows us to envision a Mars mission assembly sequence requiring some four to six launches, depending on the packaging efficiency we can attain. This is something we did once and can do again over the course of a few months, rather than many years, with the two heavy-lift pads available at KSC Complex 39.”
khallow - 24/1/2008 4:33 AMQuoteSMetch - 23/1/2008 12:45 PMI hope we’re smart enough that we never again try to place such a large system in orbit by doing it in twenty-ton chunks. I think we all understand that fewer launches of larger payloads requiring less on-orbit integration are to be preferred. Thus, a vehicle in the Saturn V class –some 300,000 lbs in LEO – allows us to envision a Mars mission assembly sequence requiring some four to six launches, depending on the packaging efficiency we can attain. This is something we did once and can do again over the course of a few months, rather than many years, with the two heavy-lift pads available at KSC Complex 39.”Perhaps it's just due to my EELV fetish, but why is putting something large in orbit 20 tons at a time a bad idea? What am I missing?Added: I guess what I'm puzzled by is how would the Shuttle and ISS observations indicate that assembly in such a manner is a problem?
500mT to LEO consumes 25 EELV launches, which is about the infrastructure limit for one EELV type for a year (one launch every two weeks). That imposes a robustness limit for the program, whatever it might be. To me, the EELV/20mT high flight rate paradigm points straight at making a true RLV development program worthwhile. Politics made our first attempt at that into STS.