HYDROGEN / OXYGEN GENERATION: The Hydrogen/Oxygen Generation System (HOGS) uses water electrolysis to provide separate oxygen and hydrogen product gases. The oxygen can be used by used by the crew for metabolic consumption, to make up for hull leakage losses, as propellant or by other on-board systems. The hydrogen can be vented to vacuum, used as propellant or sent to another system for storage and/or reuse.