Contamination Analyses of ISS Vehicle Visits

The SAGE III Contamination Monitoring Package detects the contamination environment in the immediate vicinity of the payload using eight Thermoelectric Quartz Crystal Microbalance sensors that telemeter continuous beat frequency measurements to the ground. The single greatest source of contamination measured to date was the SpaceX Cargo Dragon, whose outgassed contaminants chemisorbed to the gold electrodes of the sensors. This paper contains results from the mission’s first three years, including the signals observed from every visible visiting vehicle, the measured effects on the overall payload, and learned lessons to consider for future ISS or TQCM missions.