Neal M. Hadley

NONHAZARDOUS URINE PRETREATMENT METHOD FOR FUTURE EXPLORATION SYSTEMS

acceptance of sodium benzoate as an antifungal agent in food, and the use of organic acids as food preservatives. Urine pretreatment in use aboard the International Space Station (ISS) is based upon the strong oxidant, hexavalent chromium, and operates at a pH < 1.8, which necessitates triple containment. This carcinogenic oxidant generates harmful oxidation products in urine and is rapidly rendered inactive by oxidation-reduction reactions. In comparison, the nonhazardous urine pretreatment chemicals are stable and safe to handle with benign storage and use requirements. These characteristics will lower urine pretreatment Equivalent System Mass (ESM) by decreasing containment volume and mass, expendable chemical mass, system complexity, and crew time needed to handle pretreatment chemicals.

Advanced Plasma Pyrolysis Assembly (PPA) Reactor and Process Development

Design and development of a second generation Plasma Pyrolysis Assembly (PPA) reactor is currently underway as part of NASAs Atmosphere Revitalization Resource Recovery effort. By recovering up to 75% of the hydrogen currently lost as methane in the Sabatier reactor effluent, the PPA helps to minimize life support resupply costs for extended duration missions. To date, second generation PPA development has demonstrated significant technology advancements over the first generation device by doubling the methane processing rate while, at the same time, more than halving the required power. One development area of particular interest to NASA system engineers is fouling of the PPA reactor with carbonaceous products. As a mitigation plan, NASA MSFC has explored the feasibility of using an oxidative plasma based upon metabolic CO2 to regenerate the reactor window and gas inlet ports. The results and implications of this testing are addressed along with the advanced PPA reactor development.