[Substantiation of medical-engineering specifications for polymethyl siloxane removal by life support systems].

Analysis of experimental data about the quantitative and qualitative chemical make-up of air in the orbital station Mir and International space station (ISS) showed a permanent presence of silicon. The main source of silicon contaminants seems to be a variety of polymethyl siloxane liquids and siloxane coating of electronics. The article describes the volatile silicon contaminants detected in space stations air. To control concentrations of silicon, the existing air purification system needs to be augmented with carbons having the micropore entrance larger than diameters of silicon-containing molecules. It is also important to elaborate the technology of polymethyl siloxane liquids synthesis so as to reduce the amount of volatile admixtures emission and to observe rigorously the pre-flight off-gassing requirements with special concern about silicon coatings.

[Hygienic control of contingencies associated with local fire events aboard piloted orbital stations]. / Gigienicheskoe soprovozhdenie neshtatnykh situatsii, sviazannykh s lokal'nym vozgoraniem v usloviiakh pilotiruemykh orbital'nykh stantsii.

Based on the multiyear experience of hygienic control of the orbital stations, there are three causes of contingent air pollution: leakage of service system pipeline with chemical working bodies, spills of reagents used in biochemical and technological experiments, and air pollution by products of thermal oxidative degradation of nonmetallic materials. The authors describe their experience in successful elimination and prevention of hazardous consequences of fire aboard the space stations. Analysis of air pollution dynamics after actual fire events in the space station modules showed that it approximates a two-chamber air flow model with two phases of pollutant equilibration: first a rapid fall of concentration in the module on fire till air in the modules gets completely mixed, and then slow elimination of harmful pollutant from air. Identified were markers,--propylene and methylmetacrilate,--reacting to first signs of fire. Carbonic acid nitriles were recognized as toxic products of destruction. The positive effect of intermodular ventilation on dilution of toxic products of thermal oxidative destruction of materials was demonstrated. Satisfactory agreement of calculated and factual pollutant concentrations on board Mir permitted conclusion on applicability of the theoretical model to prediction of levels of air pollution due to contingency.