The International Space Station is brimming with bacteria and fungi that can cause diseases and form biofilms that promote antibiotic resistance, and can even corrode the spacecraft, a new study has found. The station, now over 20 years old, has been visited by more than 222 astronauts and up to six resupply missions a year up until August 2017.
NASA scientists discovered microbes mainly came from humans and were similar to those found in public buildings and offices here on Earth. The study – the first to provide a comprehensive catalogue of the bacteria and fungi lurking on interior surfaces in closed space systems – was published in the journal Microbiome.
Dr Kasthuri Venkateswaran, a senior research scientist at the NASA Jet Propulsion Laboratory and one of the study’s authors, said: “The ISS is a hermetically sealed closed system, subjected to microgravity, radiation, elevated carbon dioxide and the recirculation of air through HEPA filters, and is considered an ‘extreme environment’.” He noted that microbes are known to survive and even thrive in extreme environments. The microbes that are present on the International Space Station “could have been in existence since the station’s inception,” he added, “while others may be introduced every time new astronauts or payloads arrive.”
Venkateswaran said: “The influence of the indoor microbiome on human health becomes more important for astronauts during flights due to altered immunity associated with space flight and the lack of sophisticated medical interventions that are available on Earth. In light of an upcoming new era of human expansion in the universe, such as future space travel to Mars, the microbiome of the closed space environment needs to be examined thoroughly to identify the types of microorganisms that can accumulate in this unique environment, how long they persist and survive, and their impact on human health and spacecraft infrastructure.”