Orion Artemis i as Flown MMOD Analysis

Abstract The Orion spacecraft conducted the Artemis I flight around the Moon from November 16 through December 11, 2022. After the flight, the NASA Hypervelocity Impact Technology (HVIT) Group performed a Micrometeoroid and Orbital Debris (MMOD) analysis to predict the number of small impacts that would likely have occurred during the mission. New hypervelocity impact testing was performed to verify Ballistic Limit Equations (BLEs) used in the analysis to link impactor size and damage to the Thermal Protection System (TPS). Separately, a team from the same group inspected the Orion capsule for hypervelocity impact damage features. Potential MMOD damage found was characterized using various techniques, including optical microscopy, computed tomography scanning, and X-ray spectroscopy. The results of the inspection were compared to those of the analysis to aid in improving the analysis, including the environment models. This comparison of analysis with inspection of the hardware provides valuable insight into the MMOD environment and how accurately analysis tools assess the impact risk to spacecraft. As this was the first large, non-ablative returned surface from a lunar mission, this analysis extends the MMOD community’s insight beyond low Earth orbit into cis-lunar space.