Report of the 6th (Virtual) Meeting on the Planetary Protection Knowledge Gaps for Human Missions to Mars on June 1–2, 2022

This paper reports the sixth in a series of meetings held under the auspices of COSPAR (with space agencies support) to identify, refine and prioritize the knowledge gaps that need to be addressed for planetary protection for crewed missions to Mars, as well as to describe where and how needed data can be obtained. This approach is consistent with current scientific understanding and COSPAR policy, that the presence of a biological hazard in Martian material cannot be ruled out, and appropriate mitigations need to be in place.

The workshops in the series were intentionally organized to obtain a diverse set of inputs from subject matter experts across a range of expertise on conduct of a potential future crewed Mars exploration mission, identifying and leveraging precursor ground, cis-lunar crewed and Mars robotic activities that can be used to close knowledge gaps.

The knowledge gaps addressed by this meeting series fall into three major themes: 1. Microbial and human health monitoring; 2. Technology and operations for biological contamination control, and; 3. Natural transport of biological contamination on Mars. This report describes the findings of the 2022 meeting, which focused on measures needed to protect the crew and the returning Mars samples during the mission, both on the Martian surface and during the return to Earth.

Much of this approach to crewed exploration is well aligned with the Principles and Guidelines for Human Missions to Mars described in section 9.3 of the current (2021) COSPAR policy, in terms of goals and intent.

There were three specific recommendations:

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  The crew should be considered as a unit, meaning if one individual gets sick it will be impractical for them to be isolated from the other crew member(s) (this differs from the current COSPAR Planetary Protection Policy language).

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  Pristine life detection/subsurface samples should be kept separate from the crew during the return trip, both to keep them pristine and to protect the crew. (If there are time sensitive measurement that need to be made during the return trip they could be made on a dedicated non-pristine set of samples).

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  An approach to break the chain of contact between Mars and the Earth is still needed to protect the broader biosphere, even if crew exposed on Mars appear unharmed.