Samples of microorganisms from the surface of constructions of Mir Space Station (Mir SS) were taken and examined after 13 years of operation. The following microorganisms were isolated and identified: 12 fungal species belonging to the genera Penicillium, Aspergillus, Cladosporium, and Aureobasidium; 3 yeast species belonging to the genera Debaryomyces, Candida, and Rhodotorula; and 4 bacterial species belonging to the genera Bacillus, Myxococcus, and Rhodococcus. The predominant species in all samples was Penicillium chrisogenum. It was shown that the fungi isolated could damage polymers and induce corrosion of aluminum-magnesium alloys. We commenced a study of microbial degraders on constructions of the Russian section of the International Space Station (RS ISS). Twenty-six species of fungi, bacteria, yeasts, and actinomycetes, known as active biodegraders, were identified in three sample sets taken at intervals. We founded a collection of microorganisms surviving throughout space flights. This collection can be used to test spacecraft production materials, in order to determine their resistance to biodegradation.