In terms of planetary protection, de la Torre Noetzel pointed out that previous space experiments provided data on some of the more space-resistant microbes, such as Bacillus subtilis 168 and Bacillus pumilus SAFR-032. While these spores can survive conditions such as vacuum, radiation and temperature fluctuations during a journey to Mars, UV radiation would eventually kill them unless they could hide in cracks or pits on the spacecraft surface.
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Landing probes that are shielded from these conditions inside atmospheric entry shields (such as rovers) could host the spores for long periods of time, as the spores would be protected during the journey to Mars. Also, if the lander has shielding against UV radiation, the spores are likely to last for longer. "In this context, cryptoendolithic fungi could survive a longer period to Mars UV irradiation, taking into account the protection of rock material," she added.
The team has a new experiment on a new generation of exposed facility, called EXPOSE-R2. The experiment is called BIOMEX and began in the summer of 2014. It will compare fungi and lichens with other organisms (such as bacteria, algae and mosses) exposed to space and Mars-like conditions.
"The work will start on the ground, when EXPOSE will be back on Earth (July 2016), trying to identify which of the organisms are particularly resilient, which strategy offers the greatest protection in space, and which biological substances would be suitable as reference markers in the search for life on Mars," de la Torre Noetzel wrote. "The results will help also to determine whether they might be able to survive on other planets."
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