Planetary protection trades and lessons learned from designing Mars Sample Return’s Capture, Containment, and Return System

This paper describes the trades carried out and lessons learned while performing the preliminary design of the Capture, Containment, and Return System as part of the Mars Sample Return campaign, before the re-architecture studies initiated after December 2023. Mars Sample Return is an effort to bring to Earth rock cores, regolith, and atmospheric samples from Mars inside sealed tubes. The importance of these samples lies in their potential to provide valuable information about Mars’ geological and climate evolution, its potential ability to have harbored life in the past, and the risks posed to future human exploration by the Martian environment. The trades and lessons learned presented in this paper refer to the preliminary design solutions generated in response to the constraints levied on the payload design by backward planetary protection requirements, which impose the protection of the Earth–Moon system from any potential negative effects the returned Mars material might cause. Topics include jettison of the payload capture enclosure, replacement of the aseptic transfer system with an ultraviolet illumination system, and leveraging different design options to augment the micrometeoroid protection system to improve shielding performance.