On-orbit cryogenic fluid transfer

A number of future NASA and DOD missions have been identified that will require, or could benefit from resupply of cryogenic liquids in orbit. The most promising approach for accomplishing cryogenic fluid transfer in the weightlessness environment of space is to use the thermodynamic filling technique. This approach involves initially reducing the receiver tank temperature by using several charge hold vent cycles followed by filling the tank without venting. Martin Marietta Denver Aerospace, under contract to the NASA Lewis Research Center, is currently developing analytical models to describe the on orbit cryogenic fluid transfer process. A detailed design of a shuttle attached experimental facility, which will provide the data necessary to verify the analytical models, is also being performed.