[Investigation into fractionating of hydrogen and oxygen stable isotopes aboard the international space station].

Results of isotope investigations of atmospheric condensate and potable water supplied from Earth confirmed the fractionating of hydrogen and oxygen stable isotopes in the organism of ISS crewmembers. Samples of ISS atmospheric condensate were characterized by altered concentrations of 18O2 and deuterium. Atmospheric deuterium quantities varied in the interval of -67 to 79 +/- 3 ppm, whereas water deuterium made up -85 +/- 3 ppm as compared with SMOW.

[Consideration of the deuterium-free water supply to an expedition to Mars].

Interplanetary missions, including to Mars, will put crews into severe radiation conditions. Search for methods of reducing the risk of radiation-induced cancer is of the top priority in preparation for the mission to Mars. One of the options is designing life support systems that will generate water with low content of the stable hydrogen isotope (deuterium) to be consumed by crewmembers.

[Recovery and use of deuterium-free water in extended space expeditions].

The methods of deuterium-free water, as applied to the conditions of long-term space expeditions have been discussed. It is shown that with the use of the method of electrolysis of distilled water or urine condensate followed by the catalytic or high-temperature synthesis one can obtained water with four-fold decrease in deuterium concentration. In order to reduce the energy expenditure it is necessary to use the existing routine technologies of water and oxygen regeneration or the versions with applying the fuel cells in which hydrogen and oxygen resulting from electrolysis would generate the electrical power with simultaneous isolation of deuterium-free water.