Mountain View, California, 19 June 2015. Humans exploring Mars with pressurized rovers are unlikely to contaminate the planet biologically. So concludes a ground-breaking study by microbiologist Andrew C. Schuerger of the University of Florida and NASA Kennedy Space Center, and planetary scientist Pascal Lee of the Mars Institute, the SETI Institute, and NASA Ames Research Center. Their finding is reported in this month’s issue of Astrobiology, the leading peer-reviewed journal dedicated to advancing our understanding of life's origin, evolution, and distribution in the universe.

 

From 2009 to 2011, Lee led, with support from the Mars Institute, the SETI Institute, and NASA, the Northwest Passage Drive Expedition, a record-setting 750 km crewed vehicular traverse in the Arctic. The goal of the expedition was to drive the Haughton-Mars Project (HMP) Okarian vehicle, a modified Humvee simulating a pressurized rover for future human Mars exploration, from the North American mainland to the HMP Research Station on Devon Island, High Arctic, by way of the Northwest Passage. The expedition took three field seasons to complete and was ultimately a success. “It was a challenging journey” recalls Lee, “but it taught us a lot about future road trips on Mars”.

 

During the 2009 field season, the HMP Okarian journeyed 500 km on sea-ice from Kugluktuk to Cambridge Bay, Nunavut, Canada, with multiple overnight and science stops. Along the way, samples of grit and snow were collected from inside and outside the vehicle to investigate whether, and the extent to which, human-associated microbes (bacteria and fungi) transported by the Okarian and her crew of five, might have found their way onto the surrounding pristine snow surface outside the vehicle.

 

The samples collected by Lee were shipped frozen to Schuerger’s lab at NASA Kennedy Space Center for analysis. The result: only a minute fraction of microbial species identified on board the rover were detected outside the vehicle. “Forward contamination was surprisingly very low”, says Schuerger. “Furthermore, the number of microbial species inside the rover decreased over time, due to the expedition’s isolation and the harshness of Arctic conditions.”

 

The authors of the study conclude that given how much harsher the Martian surface environment is, compared to the Arctic, significant forward contamination of Mars during pressurized rover traverses, even with multiple stops and EVAs (Extra-Vehicular Activity or spacewalks), is unlikely.

 

The researchers acknowledge that theirs is a preliminary study, with so far only limited seed funding to enable it. “We need to remain cautious. More detailed studies are necessary to confirm our initial results” recognizes Lee. “But this early finding is cause for some encouragement and reassurance. Road trips on Mars might not automatically result in a planetary protection disaster”. Schuerger concurs: “I agree we need to remain careful, but this does bode well for the human exploration of Mars.” The scientists hope to be able to confirm these initial findings with additional field studies.

 

For more information:

 

Article in Astrobiology by Schuerger & Lee:

Schuerger, A. C., and P. Lee 2015. Microbial ecology of a crewed rover traverse in the Arctic: Low microbial dispersal and implications for human Mars missions. Astrobiology, 15(6), 478-491.

 

Authors:

Andrew C. Schuerger: E-mail: schuerg@ufl.edu

Pascal Lee: E-mail: pascal.lee@marsinstitute.net

 

Northwest Passage Drive Expedition:

Polar Trek to Mars , a SETI Talk by Pascal Lee: https://www.youtube.com/watch?v=NVyUs_rWbjw

 

 

Mars Institute:

Christopher Hoftun, CEO, Mars Institute. E-mail: christopher.hoftun@marsinstitute.net