Utilizing a water vapor feed is highly attractive for laboratory and small industrial scale electrolyzers. Giner Electrochemical Systems, LLC. is the world's largest supplier of laboratory electrolyzer stack and stack parts. These electrolyzers have excellent proven durability, greatly exceeding five years. However, they require an extremely pure deionized water feed. The ability of a vapor-fed electrolyzer to operate on tap water would make this technology even more attractive for these applications. In a similar fashion to water permeation through an ionomeric membrane, alcohols such as methanol and ethanol can permeate membranes. Thus the static vapor feed technology may be useful in alcohol-air batteries such as those used for portable power. In all these applications, the management of the gases and liquids involved generates significant complexity that inevitably increases the cost and reduces reliability of such devices. As such, they will all benefit from static water vapor feed technologies. Lunar and space stations, satellites, high altitude aircraft. Terrestrial water electrolyzers typically utilize an abundance of recirculated water to the electrolyzer, usually on the anode (oxygen) side, where it serves reactant, coolant, and as the "carrier" phase wherein the product oxygen is carried from the anode by the pumped water. Subsequent to leaving the electrolyzer the phases are separated by gravity in a receiving tank. In near-zero or low-gravity environments, this separation is difficult to achieve. Doing so results in additional system complexity and compromised process efficiency. As part of a regenerative fuel cell system, NASA has a need for highly-efficiency, but robust technologies capable of storing energy in the form of stored hydrogen and oxygen. The Static Water Vapor Feed (SWVF) Electrolyzer is an elegant solution to overcome and simplify the above problems. Thus NASA will be the first to utilize electrolyzers with this technology, possibly in the Constellation mission in the lunar-based and Martian energy storage systems.