Review of the knowledge of microbial contamination of the Russian manned spacecraft

Abstract

The 15-year experience of orbital station Mir service demonstrated that specifically modified space vehicle environments allows for the consideration of spaceship habitats as a certain ecological niche of microbial community development and functioning, which was formed from the organisms of different physiological and taxonomical groups. The base unit of the orbital station (OS) Mir was launched on February 20, 1986, and on March 13 the first crew arrived to it. From that moment a unique microbiocenosis started forming in the closed environment of the space station, and vital activity of the microorganisms continued for the next 15 years in a specifically changed environment, in conditions of continuous influence of a set of factors intrinsic to space flight. A total of 234 species of bacteria and fungi were found onboard orbital station Mir, among which microorganisms capable of resident colonization of the environment of space objects as a unique anthropotechnological niche were revealed. In such conditions the evolution of microflora is followed by the rise of medical and technical risks that can affect both sanitary-microbiological conditions of the environment and the safety and reliability characteristics of space equipment. The latter is caused by progressing biological damage to the structural materials. The microbial loading dynamic does not have linearly progressing character, but it is a wavy process of alternation of the microflora activation and stabilization phases; on this background there is a change of the dominating species by quantity and prevalence. The accumulated data is evidence of the necessity of the constant control of the microbial environmental factors to maintain their sanitary and microbiological optimum condition and to prevent the processes of constructional materials biodestruction.