The Evolution of Cryogenic Storage Systems Toward Advanced Spacecraft Missions
The application of cryogenic fluid storage systems to manned spacecraft is considered attractive primarily because of the substantial weight and volume saving afforded compared with high-pressure gaseous storage at ambient temperature. The major use of the stored fluids has been as a metabolic support (oxygen) and as reactant supply (hydrogen and oxygen) to the fuel cell for power generation. In addition cryogenic helium is used for descent propellant tankage pressurization aboard the lunar module. The subsystems developed for the NASA Gemini program, the firts full-scale operational application of this type of equipment, are discussed as a baseline for comparison with more advanced designs for subsequent programs. State-of-the-art design improvements are presented in some detail. Current programs (i.e., Apollo, Lunar Module, Biosatellite (primate), Manned Orbiting Laboratory, and the Air-lock Module) utilize cryogenic storage and supply subsystems for the usages mentioned earlier.