Science Mission Directorate's Science and Planetary Protection in Advance of Human Missions Workshop Report

NASA's Mars Exploration Program hosted the Science and Planetary Protection in Advance of Human Missions to Mars Workshop as the first in a new series developed to engage the Mars science community in the planning process for precursor science, and ultimately human exploration, on Mars. The PP discipline focuses on preventing harmful contamination during space exploration activities as well as eliminating adverse impacts to Earth’s biosphere from returned materials, referred to as forward and backward PP, respectively. Unlike robotic exploration where the potential for harmful contamination can be controlled and mitigated prior to launch and during operations, the unique requirements of human exploration introduce elevated and fluctuating levels of microbial bioburden and organic loads. When humans go to Mars, they will not be living in a closed system; the crew will be exposed to Martian materials, and the Martian surface will be exposed to terrestrial materials. With these considerations in mind, MEP asked workshop participants to discuss the overall sequence of Martian exploration. Among many findings, attendees placed significant emphasis on the importance of returning samples collected by the Perseverance rover to Earth in advance of crewed exploration, as a path to closing key knowledge gaps such as contamination transport (weather) and dust characteristics with implications for human mission execution. Additionally, a significant segment of the participants recommended that NASA make further attempts to look for life on Mars using robotic missions before sending crewed missions. This would be a conservative strategy for mitigating against unprecedented potential for terrestrial contamination associated with a crewed mission. However, there was not unanimity among attendees on whether it should be mandatory for such investigations to be completed before the first crewed mission. Beyond knowledge gap closure and life detection, participants argued strongly for preparatory precursor activities to support the science activities that would be conducted on a crewed mission. For example, attendees highlighted high-fidelity surveillance of human landing sites (using orbital assets or drones, for example) as one method to increase efficiency of crewed traverses. Contributors also advocated for NASA to send robotic missions to pre-select samples and pre-deploy drilling payloads in the interest of maximizing efficient use of crew time. Overall, the workshop continued to reinforce the need for precursor missions to characterize Mars and determine the presence or absence of human-affective biohazards from the Mars environment. Ideally, this would happen before crew arrives on the surface, with Mars weather, landing site characterization, and pristine science being the three principal drivers.