Induced-Contamination Predictions for the Micro-Particle Capturer and Space Environment Exposure Device

Abstract

The return of International Space Station external experiments provides an opportunity to compare calculations of induced contamination with measurements from flight hardware. The Japan Aerospace Exploration Agency's Micro-Particle Capturer and Space Environment Exposure Device, which was attached to the exterior of the Russian service module, is one such experiment. The Micro-Particle Capturer and Space Environment Exposure Device experiment was purposed for particle capture (i.e., micrometeoroids and orbital debris) and materials exposure over varied durations. The experiment consisted of three identical units, which were mounted outside the International Space Station for periods ranging from 10 months to almost 4 years. X-ray photoelectron spectroscopy of various locations on the three Micro-Particle Capturer and Space Environment Exposure Device units has shown up to 950A of contamination deposition. Contamination analyses were performed to compare with measured contamination levels on each Micro-Particle Capturer and Space Environment Exposure Device unit. Material outgassing and thruster plume induced contamination were calculated using analytical and semi-empirical models developed by the Boeing Space Environments Team. Measurable levels of silicon-based contamination were predicted on the ram side, whereas a combination of silicon-based and thruster plume induced contamination was predicted for the wake side. Predictions of contamination depths were within a factor of 3, showing good agreement with measured contamination.