Mars sample return campaign: Biological risk and a proposed sample safety assessment protocol

G. McDonnell; L.E. Mayhew; A. Steele; S. Siljeström; B. M. Ahern; N. Baird; R.E. Davis; Katherine L. French; M. Glamoclija; H. Graham; K. B. Hummel; W. Page; N. Pearce; A. Regberg; D. Relman; M. A. Sephton; B. Sherwood Lollar; J. Vanhomwegen; M.B. Wilhelm; B. Shirey; D.W. Beaty

doi:10.1128/aem.02461-25

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Mars sample return campaign: Biological risk and a proposed sample safety assessment protocol

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Abstract

Returning surface samples from Mars to Earth has been a major planetary science objective, with the potential for the detection of microbiological life and the possibility of improving our understanding of the origins of life. The National Aeronautics and Space Administration and the European Space Agency assembled a team to assess the level of risk that returned samples could contain potential biohazards. The team was chartered with optimizing previous sample safety assessment strategies, defining what constitutes a biological hazard, developing a protocol to test for biohazards, and establishing a statistical framework to determine if samples may be safe for release from a high-containment facility. This report presents the biological context for a proposed three-step protocol for testing returned samples, including how to determine if microorganisms are present, and if they could be (or were recently) alive.

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G. McDonnell, L.E. Mayhew, A. Steele, S. Siljeström, B. M. Ahern, N. Baird, R.E. Davis, Katherine L. French, M. Glamoclija, H. Graham, K. B. Hummel, W. Page, N. Pearce, A. Regberg, D. Relman, M. A. Sephton, B. Sherwood Lollar, J. Vanhomwegen, M.B. Wilhelm, B. Shirey, D.W. Beaty. 2026. Mars sample return campaign: Biological risk and a proposed sample safety assessment protocol. https://doi.org/10.1128/aem.02461-25

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