Less restrictive “bioburden” rules would simplify missions to Mars

Animation showing an artist’s interpretation of the inner structure of Mars. Credit: NASA / JPL-Caltech

A new report that could make it easier to send spacecraft to certain regions of March while protecting the planet from terrestrial contamination was presented today at a press conference at the 53rd Annual Meeting of the Planetary Science Division of the American Astronomical Society by Senior Scientist at Planetary Science Institute, Amanda Hendrix.

The report from the National Academies of Science, Engineering and Medicine identifies criteria that could allow robotic missions to be carried out to certain locations on Mars with less restrictive “bioburden” requirements, designed to prevent harmful contamination by from terrestrial microbes to Mars.

“The Planetary Protection Committee, a standing committee of the National Academies Space Studies Board, was appointed by Nasa write a report on criteria that could be used to designate regions on Mars where missions can land with less stringent bioburden requirements than those currently in place. Currently, meeting planetary protection requirements – for example, using rigorous sterilization techniques – can be seen as overwhelming, expensive and complex, and it may be that these restrictions can be simplified and modernized, in some cases, which may can help make certain areas of Mars more accessible, ”said Hendrix, co-chair of the committee that wrote the report.

“The report suggests techniques for modernization and flexibility in the implementation of planetary protection. One way to do this is to use a risk management approach, which could be tailored to the needs of each mission, ”said Hendrix. “The committee’s findings may lead to making parts of Mars more accessible to commercial and government enterprises by relaxing planetary protection requirements while remaining cautious about access to potential habitable areas.”

This map of Mars shows the locations where ice is potentially located within one meter of the surface, based on neutron spectroscopy (Mars Odyssey) or thermal infrared (IR) spectra (Mars Climate Sounder) data, and includes underground access points known to candidate Mars. Catalog of the cave. Gray regions are those that lack IR data and give water equivalent hydrogen (WEH) contents of less than 10% from neutron spectroscopy. In gray areas, closed system ice or brine could be present in the first meter, but it is likely to be low in abundance and uneven distribution. Gray regions may be appropriate for missions planning underground activities (up to 1 meter deep) with reduced bioburden requirements, if landing sites are a conservative buffer distance from underground access points. Credit: A. Deanne Rogers, Stony Brook University, The State University of New York

In that report, the committee focused on regions of Mars that might not be adversely affected if visited by spacecraft that are not rigorously sterilized. For missions that do not access the subsoil, these regions could include a significant portion of the surface of Mars, because the UV environment is so biocidal that terrestrial organisms are, in most cases, not susceptible to survive more than one to two sols, or Martian days. For missions that access underground (up to 1 meter), regions on Mars that are expected to have patchy or no water ice below the surface could also be visited by spacecraft with more bioburden requirements. flexible, because such uneven ice is probably not conducive to the proliferation of terrestrial microorganisms.

The report finds it imperative that any mission sent to Mars with reduced bioburden requirements remain a cautious distance from any underground access points, such as cave openings. In addition, although less stringent than current requirements, those missions with relaxed microbial load requirements would still require a certain level of cleanliness, which could be achieved for example by using standard aerospace cleanliness practices.

“The whole purpose of planetary protection protocols is to minimize the risk of harmful contamination; this means minimizing the risk of introducing terrestrial biological material that could disrupt future life detection experiments. It’s really important in the case of Mars, ”said Hendrix. “On Mars, we know that the surface is almost certainly uninhabitable for terrestrial microorganisms, due to the harsh UV environment; however, underground regions such as caves, sheltered from radiation, could be habitable areas, for terrestrial and / or native Martian life.

“The report will aid the search for life on Mars by identifying areas of its surface for which planetary protection standards for spacecraft must be most restrictive,” said Hendrix. “In addition, by potentially lightening the burdens of planetary protection in exploring other areas, NASA could allow more missions to Mars that help us understand the planet and its environment, even if those missions do not pursue astrobiological studies. “

The committee’s conclusions apply specifically to missions for which NASA is responsible for protecting the planet. For trade missions in which NASA has no role or link, the US government must still designate a regulatory body to authorize and continuously oversee space activities in accordance with the Outer Space Treaty, the report said. The study was funded by NASA.