Orion exploration flight test post-flight inspection and analysis

The principal mechanism for developing orbital debris environment models, is to make observations of larger pieces of debris in the range of several centimeters and greater using radar and optical techniques. For particles that are smaller than this threshold, breakup and migration models of particles to returned surfaces in lower orbit are relied upon to quantify the flux. This reliance on models to derive spatial densities of particles that are of critical importance to spacecraft make the unique nature of the Exploration Flight Test 1 (EFT-1) return surface a valuable metric. To this end detailed post-flight inspections have been performed of the returned EFT-1 backshell, and the inspections identified six candidate impact sites that were not identified during the pre-flight inspections. This paper describes the post-flight analysis efforts to characterize the EFT-1 mission craters. This effort included ground based testing to understand small particle impact craters in the thermal protection material and multiple post-flight inspections. Crater analysis has been performed using optical, X-ray computed tomography (CT) and scanning electron microscope (SEM) techniques. Finally, numerical simulations have been performed to bridge the gap between the ground based testing and the crater characterization findings. Each of these analyses are discussed here, along with, environment calculation implications.