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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.

The Federal Government is increasingly interested in potential commercial applications for technology developed under Government funding. This emphasis has been especially evident in the Small Business Innovative Research (SBIR) Program. Experiences in commercialization efforts are presented. Benefits as well as hindrances of Government policies and regulations are discussed. Suggestions are presented based on a Small Business perspective as well as that of a Government Technical Monitor. Experience has proven that advancement to Phase III commercialization is a slow tedious process and is dependent upon a number of variables. Some technologies, such as communications, microprocessing, and medical systems are directly marketable both inside and outside of the Government.

The 60-Day and 90-Day closed manned chamber tests conducted by the McDonnell Douglas Corporation in the 1960s have been thoroughly reported in the literature. These tests evaluated, among other things, the leading water recycling systems developed at that time. During both tests, crew members ingested water reclaimed from urine and humidity condensate and performed personal hygiene tasks with water recycled in a separate loop. Since then, to this date (1995), no comparable testing has been carried out in the United States. Now, however, plans are being made to test modern water recycling systems in chamber tests with humans. This paper summarizes the earlier testing and highlights the lessons that were learned.

This paper describes a newly designed, 2.7 Kg (6 pound) capacity, laundry machine called the Single Phase Space Laundry (SPSL). The machine was designed to wash and dry crew clothing in a micro-gravity environment. A prototype unit was fabricated for NASA-JSC under a Small Business Innovative Research (SBIR) contract extending from September 1990 to January 1993. The unit employs liquid jet agitation, microwave vacuum drying, and air jet tumbling, which was perfected by KC-135 zero-g flight testing. Operation is completely automated except for loading and unloading clothes. The unit uses about 20 percent less power than a conventional household appliance.

The Microbial Check Valve (MCV) is used on the Space Shuttle to impart an iodine residual to the drinking water to maintain microbial control. Approximately twenty MCV locations have been identified in the Space Station Freedom design, each with a 90 day life. This translates to 2400 replacement units in 30 years of operation. An in situ regeneration concept has been demonstrated that will reduce this replacement requirement to less than 300 units based on data to date and potentially fewer as further regenerations are accomplished. A totally automated system will result in significant savings in crew time, resupply requirements and replacement costs. An additional feature of the device is the ability to provide a concentrated biocide source (200 mg/liter of I2) that can be used to superiodinate systems routinely or after a microbial upset. This program was accomplished under NASA Contract Number NAS9-18113.

The extravehicular activity (EVA) requirements for Space Station Freedom and future long-duration space missions demand advanced technologies for the life support subsystems in the astronaut portable life support system (PLSS). A NASA-funded program is currently underway to develop a full-scale, breadboard, regenerate metal oxide carbon dioxide (CO2) removal system. This technology is a promising concept to replace the lithium hydroxide absorber presently used for removing CO2 in the recycled breathing gas in the PLSS, but cannot be efficiently regenerated to be used for another EVA mission. In the metal oxide carbon dioxide removal system, an “active” metal oxide compound, contained within a solid absorbent material, effectively removes the CO2 by chemically reacting to form a metal carbonate during astronaut EVA. The absorbent is then regenerated thermally, by decomposing the resulting carbonate and thereby releasing CO2, to reform the metal oxide.

Throughout the history of manned space flight the supply of potable water to the astronauts has presented unique problems. Of particular concern has been the microbiological quality of the potable water. This has required the development of both preflight water system servicing procedures to disinfect the systems and inflight disinfectant addition and monitoring devices to ensure continuing microbiological control. The disinfectants successfully used to date have been aqueous chlorine or iodine. Because of special system limitations the use of iodine has been the most successful for inflight use and promises to be the agent most likely to be used in the future. Future spacecraft potable, hygiene, and experiment water systems will utilize recycled water. This will present special problems for water quality control. NASA is currently conducting research and development to solve these problems.

Waste water pretreatment and recovered water posttreatment techniques are essential for Space Station life support in order to achieve the necessary quality required of recycled water. This paper identifies methods of pre- and post-treatment applicable to spacecraft water recovery by distillation. The results of laboratory investigations show that oxidizers, which typically have been components of urine pretreatment formulas, produce many volatile organic compounds that contaminate the distillate and must later be removed by posttreatment. Two new nonoxidizing urine pretreatment formulas have been tested which minimize the generation of volatile organics and thereby significantly reduce posttreatment requirements. Three posttreatment methods were identified from among the many candidates that look promising (either alone or in combination) for removing organic contaminants in recovered water to nondetectable or barely detectable levels.