Mars Sample Return Campaign: Biological Risk and a proposed Sample Safety Assessment Protocol

Returning surface samples from Mars to Earth has been a major planetary science objective. In short, it has the exciting potential for the detection of microbiological life, be it extant or extinct, and the possibility of improving our understanding of the origins of life. The joint National Aeronautical and Space Administration (NASA) and the European Space Agency (ESA) Sample Receiving Project (SRP) assembled a team to assess the level of risk that returned samples could contain potential biohazards, a critical tenant of planetary protection. The team was chartered with optimizing previous sample safety assessment strategies, defining what constitutes a biological hazard, developing a protocol to test for potential biohazards, and establishing a statistical framework to determine if samples may be safe for release from the planned high-containment Sample Receiving Facility (SRF). This meeting report presents the committee’s proposed 3-step rigorous protocol for testing the returned samples for biological hazards, including how to determine if microorganisms are present, even at a low abundance, and if they could be - or were recently - alive.