Astronauts Swab the Exterior of Station for Microbial Life

Astronaut Butch Wilmore collecting microorganism samples on the exterior of the ISS.
Astronauts ventured outside the International Space Station to collect microbiological samples during crew spacewalks for the ISS External Microorganisms experiment. This investigation focuses on sampling at sites near life support system vents to examine whether the spacecraft releases microorganisms, how many, and how far they may travel.
This experiment could help researchers understand whether and how these microorganisms survive and reproduce in the harsh space environment and how they may perform at planetary destinations such as the Moon and Mars. Extremophiles, or microorganisms that can survive harsh environments, are also of interest to industries on Earth such as pharmaceuticals and agriculture.
We can’t sanitize everything we send to space and humans carry their own microbiomes and continuously regenerate microbial communities. It’s important to understand and address how well current designs and processes prevent or limit the spread of human contamination. The data could help determine whether changes are needed to crewed spacecraft, including spacesuits, that are used to explore destinations where life may exist now or in the past.
You can watch the entire spacewalk here.

Astronaut Butch Wilmore collecting microorganism samples on the exterior of the ISS.

Astronaut Butch Wilmore collecting microorganism samples on the exterior of the ISS.

Astronaut Butch Wilmore collecting microorganism samples on the exterior of the ISS.

A member of the ISS External Microorganisms payload development team demonstrates removing a swab from the sampling caddy that is used by an astronaut during a spacewalk.
For more information, visit
https://www.nasa.gov/mission/station/research-explorer/investigation/?#id=7715
Credits
NASA
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Technical support
- Amy Moran (Global Science and Technology, Inc.)
Release date
This page was originally published on Monday, March 30, 2026.
This page was last updated on Monday, March 30, 2026 at 6:27 PM EDT.