Search Results

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.

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.

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.