Mars 2020 Sample Caching System Contamination: How to Clean Hardware and Keep it Clean

The Mars 2020 Rover has the capability to collect and cache samples for potential Mars sample return. Specifically, the sample caching system (SCS) is designed for coring Mars samples and acquiring regolith samples as well as handling, sealing and caching on Mars. As the potential first Martian samples that could be returned to Earth, assuring low levels of terrestrial contamination is of the utmost concern. In developing the SCS, the project prioritized limiting sample contamination in organic, inorganic and biological areas. The focus of this paper is on the strategies implemented to clean and maintain cleanliness throughout the assembly of hardware as well as the challenges and lessons learned to maintain stringent contamination requirements.