The International Space Station is filled 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, built in 1998 and orbiting around 250 miles above the Earth, has been visited by more than 222 astronauts and up to six resupply missions a year up until August 2017. Each time every astronaut goes up to the station, they could potentially bring up bacteria which then spreads within the sealed environment of the space station. Although the capsules the astronauts traveled in were built in sterile environments before being sent into orbit and routine monitoring has taken place, a comprehensive catalog of what bacteria are present in the ISS has only just been determined. NASA scientists discovered microbes mainly came from humans and were similar to those found in public buildings and offices here on Earth.
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.
Dr. Venkateswaran added: "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." Researchers say the study can be used to help improve safety measures that meet NASA requirements for deep space human habitation.
The joint first author of the study postdoctoral scholar Dr. Camilla Urbaniak at JPL added, "Some of the microorganisms we identified on the ISS have also been implicated in microbial induced corrosion on Earth. However, the role they play in corrosion aboard the ISS remains to be determined."
