Planetary Protection Knowledge Gap Closure Enabling Crewed Missions to Mars

As focus for exploration of Mars transitions from current robotic explorers to development of crewed missions, it remains important to protect the integrity of scientific investigations at Mars, as well as protecting the Earth’s biosphere from harmful effects. This is the discipline of planetary protection, and COSPAR (the Committee on Space Research) maintains the consensus international policy and guidelines on how this is implemented. In the early 2010s, COSPAR identified that, despite guidelines for crewed missions being in place, gaps in knowledge meant that a spacecraft designer could not design a crewed Mars exploration mission, based on current information, that would demonstrate compatibility with the intent of the Outer Space Treaty. Beginning in 2016, COSPAR then sponsored a multi-year interdisciplinary meeting series to address these planetary protection “knowledge gaps” (KGs) with the intent of refining the current robotic-focused Planetary Protection Policy to more adequately support the implementation of crewed exploration missions. This paper describes the outcome of the interdisciplinary COSPAR meeting series, to describe and address these KGs, as well as identify potential paths to gap closure. It includes the background scientific basis for each topic and knowledge updates since the meeting series. The paper includes a KG data table intended to be a point of departure for making future progress in developing an end-to-end planetary protection requirements implementation solution for a crewed mission to Mars.