Four significant micro-meteoroid orbital debris (MMOD) impact events on the shuttle are documented: two perforations of the payload bay door radiator sandwich panel along with craters in a crew module window and a wing leading edge reinforced carbon-carbon panel. Results from Scanning Electron Microscope/Energy-Dispersive x-ray Spectroscopy (SEM/EDS) analysis of impact residue are provided in an attempt to identify the source of each impact. Particle sizes that could produce the observed damage are discussed, along with hypervelocity impact testing on representative samples conducted to simulate the impact event.
