Contamination levels measuring in external induced atmosphere of Russian orbital stations and the Russian segment of the International Space Station

In view of the increasing number of science experiments being carried out in the Russian Segment of the International Space Station, there is a growing interest in the state of the environment where they are conducted, especially, in the contaminating effects of the external induced atmosphere. Sources of the induced atmosphere contamination are the outgassing of non-metallic materials of the outer coatings, firings of control system thrusters and exhausts of various venting systems, as well as dust particles remaining on the external surfaces after launch from Earth, atmospheric aerosols and space dust. The paper presents results of quartz crystal microbalances molecular depositions measurements that were used for evaluating contamination in the induced atmosphere of the first Soviet orbital stations Salyut-7 and Mir, as well as modules Pirs and Poisk of the Russian Segment of the International Space Station. The results of the experiments show a significant effect of illumination and thermal conditions of the contamination source and the quartz microbalance sensor on the measurement results.