New ISS Experiment Tests Organisms’ Survival Skills in Space

Biological samples will be exposed to the harsh environment outside the space station.

Expose-R is fixed to the outside of the International Space Station.

The International Space Station has a new tool for studying how living things fare in the unforgiving environment of space.

BIOMEX, the Biology and Mars Experiment, is one of four experiments in the Expose-R2 facility, which was launched to the station in July onboard a Progress cargo vehicle. Since August 20, two of the facility’s “Space Trays” have been exposed to the vacuum outside the ISS. Starting in October, the samples will face complete space conditions, including solar and cosmic radiation.

BIOMEX is an international project involving 26 institutions, and is led by Jean-Pierre de Vera of the German AeroSpace Center. The experiment contains numerous chambers in which organisms such as bacteria, archaea, fungi, lichen, and mosses, as well as large organic molecules, can be exposed to space conditions for 12 to 18 months. Some of these biomolecules and organisms are mixed in with Mars-like soil.

The objective of BIOMEX is to test to what extent cell components and organisms can resist the rigors of space, including conditions they would be exposed to on Mars. Once the experiment is complete (after about a year) and the samples are returned to Earth, they’ll be examined in detail. It will be of particular interest to learn what signs of life will be left after the organisms have been exposed to vacuum, radiation, desiccation, and other stresses.

BIOMEX is not the only experiment on the Expose-R2 facility. Another study called BOSS (Biofilms Organisms Surfing Space) will test biofilms of microbes and plankton, and will have objectives similar to those of BIOMEX. Microorganisms in natural environments mostly occur in the form of biofilms, which protect them and make them more resistant to external stresses.

These kinds of experiments are a critical first step in gaining the essential biological information we’ll need to undertake human missions to Mars and beyond. The data also will help us to evaluate the panspermia hypothesis—the idea that microorganisms can survive the journey from one planet to another.

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