High Pressure Water Electrolysis for the Space Station

The benefits and penalties associated with the generation of high pressure gases using the SPE® water electrolysis subsystem are presented. The Space Station has a number of requirements for oxygen and hydrogen generation at very high pressures (between 1000 and 6000 psia) including emergency pressurization and repressurization of habitability and laboratory modules, recharge of the Extravehicular Mobility Unit (EMU) oxygen tanks, and propulsion capability for Station reboost and attitude control. The traditional trade study parameters of weight, volume, power, and heat rejection are considered. The ramifications of the use of a high pressure, solid polymer electrolyte-based system are discussed with respect to Space Station safety and maintenance.