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Water is of critical importance to space missions due to crew needs and the cost of supply. To control mission costs, it is essential to recycle water from all available wastes - both solids and liquids. Water recovery from liquid water wastes has already been accomplished on space missions. For instance, a Water Recycling System (WRS) is currently operational on the International Space Station (ISS). It recovers water from urine and humidity condensate and processes it to potable water specifications. However, there is more recoverable water in solid wastes such as uneaten food, wet trash, feces, paper and packaging material, and brine. Previous studies have established the feasibility of obtaining a considerable amount of water and oxygen from these wastes (Pisharody et al, 2002; Fisher et al, 2008; Wignarajah et al, 2008).

The electrosynthesis of expendable reagents including acids, bases, and oxidants from simple salts or salt mixtures has been demonstrated using a variety of electrochemical cells. A five chambered electrodialytic water splitting (EDWS) cell with bipolar membranes was utilized to efficiently convert sodium sulfate, sodium chloride, potassium nitrate, and potassium chloride to conjugate acids and bases. With the same cell, selective segregation of cations and anions from mixed salt solutions occurred, resulting in relatively pure acids and bases. These results suggest that pure acids and bases can be produced from composite spacecraft brines. Chemical oxidants such as sodium and ammonium persulfate were also synthesized with high current efficiencies by the electrooxidation of salts and acids in a two chambered electrochemical cell.