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Reliable data on human metabolic materials are essential for designing environmental control and life support systems (ECLSS) in manned space facilities. This paper presents results from detailed analyses of human metabolic gases, including trace gases, breath, and water vapor collected from twenty healthy subjects of Japanese, and of urine from thirty-three volunteers that was stored at room temperature and at low temperature for seven days. The most SMAC-critical trace gas was carbon monoxide, which was detected in abundance in smoker's breath samples. The urine preserved at room temperature for one week indicated remarkable changes in constituent concentrations, suggesting metabolic activity of microorganisms in the urine sample. These results are being used to develop, test, and operate a trace contaminant removal system and the water reclamation system for a regenerative ECLSS, to evaluate the efficiency of the systems, and to monitor the quality of the closed environment.

The photocatalytic oxidation of trace contaminants such as human metabolite gas and outgas from the component materials over a UV-illuminated film of titanium dioxide (TiO2) has been studied to apply for an environmental purification in manned spacecraft. The trace contaminants studied were as follows: methanol, ethanol, acetal-dehyde, toluene, acetone, methane, ethylene, ammonia, 1,4-pentadiene, hydrogen sulfide, carbonyl sulfide, hydrogen and carbon monoxide. Most of these compounds are the representative human metabolic gas. It was found that these compounds except for methane, ethylene, carbonyl sulfide, hydrogen and carbon monoxide are sufficiently removed in the photocatalytic reactor. This report describes the result of the removal test using the photocatalysts performed in National Space Development Agency of Japan/Tsukuba Space Center (NASDA / TKSC).