Recommendations for Water Systems in Future Space Applications

The International Space Station (ISS) has been an excellent test bed for integration of multiple systems. Various types of ISS water (potable, technical, condensate, waste water, and cooling loop water) are encompassed by three ISS systems: Environmental Control and Life Support System (ECLSS), Extravehicular Activity (EVA) system, and Internal Active Thermal Control System (IATCS). Numerous on-orbit variables occur through water interactions within each system independently and, in some cases, via integration of the three systems. Since ISS activation, several lessons have been learned which may be used to simplify future water resupply and recovery systems. These include lessons on precise documentation of water quality and compatibility, water biocide types and interactions, stowage of water containers, compatible water pumps, flow indicators, standardized containers and connections, distinct labeling, and anticipation of on-orbit changes. This paper describes the issues encountered on ISS and suggests solutions for future systems in the form of recommendations and questions posed to the future designers.