Contamination control program for the Psyche asteroid mission

Psyche is a NASA Discovery-class mission that is designed to visit the metallic asteroid (16) Psyche to determine its origin and conditions of formation and to understand whether parallels between the asteroid and the cores of terrestrial planets can be drawn. [1] The Psyche instrument suite consists of a magnetometer, a gamma ray and neutron spectrometer (GRNS), the Psyche Multispectral Imagers (PMI) and the Deep Space Optical Communications (DSOC) technology demonstration payload. PMI and DSOC drive the overall contamination sensitivity of the Psyche mission. Unique contamination analysis challenges for the Psyche mission included: developing a novel molecular contamination transport model for parametric assessments of outgassing risk [2]; implementing a contamination-induced optical throughput degradation model; justifying the need for a T-0 purge and deployable aperture cover for DSOC; and modelling the sputtering and transport of contaminants due to electric propulsion system plume impingement. Contamination control implementation challenges on Psyche included: using a commercial telecommunications satellite bus to host scientific instruments; interfacing with a new spacecraft contractor; and creating a "chamber inside a chamber" for spacecraft TVAC to protect JPL's 25ft Space Simulator. [3] This work describes JPL's Contamination Control program for the Psyche mission, including the planning and execution of strategies to resolve those mission-unique challenges in preparation for launch.