Spacecraft start out clean – as close to germ-free as humans can make them. But after years of use, unused spaces within the walls can become home to unwanted life forms.
When NASA joined the Russian space program in its evaluation of the microbial activity aboard the Mir spacecraft, they made some interesting discoveries. NASA’s plan was to obtain information that would be useful during long-duration missions.
Mir had suffered several power outages during its fifteen years in low earth orbit; temperature and humidity had gone well beyond normal levels. In 1998, NASA astronauts were collecting samples from air and surfaces. Imagine their surprise when they opened an obscure service panel in Mir’s Kvant-2 Module and discovered a free-floating mass of water.