Active control of cryogenic propellants in space

A new era of space exploration is being planned. Exploration architectures under consideration require the long term storage of cryogenic propellants in space. This requires development of active control systems to mitigate the effect of heat leak. This work summarizes current state of the art, proposes operational design strategies and presents options for future architectures. Scaling and integration of active systems will be estimated. Ideal long range spacecraft systems will be proposed with exploration architecture benefits considered.

► There are numerous benefits to using cryogenic propellant depots in space.
► Should design for operability, including active thermal and fluid control.
► One option is water launch, with in-space electrolysis and LOX/LH2 liquefaction.
► Hi-capacity refrigeration/liquefaction cycles are sized and optimized for stage temperatures.
► Concept of operations and vehicle mass and power budgets are analyzed.