Regenerable non-venting thermal control subsystem for extravehicular activity

Extravehicular Mobility Unit heat rejection requirements have been formulated for both Space Shuttle Orbiter and space station regenerable nonventing thermal sink (RNTS) applications, where the former involve nonventing extravehicular activity (EVA) missions and the latter both nonventing and regenerable EVA. The present conceptual study notes that while the exclusive use of thermal storage is suitable for the Space Shuttle mission, space station requirements are best satisfied by a hybrid system which combines thermal storage with radiator and heat pump. The Space Shuttle RNTS thermal control subsystem's thermal storage unit uses water as a phase change medium. It is noted that the same heat storage unit can satisfy the Space Shuttle and space station requirements.