Design and evaluation of additively manufactured polyetherimide orbital debris shielding for spacecraft

The increasingly congested orbital environment around Earth threatens the safety of space assets. Micrometeoroids and orbital debris (MMOD) less than 1 cm but traveling at hypervelocities pose a serious but defensible hazard. Traditional shields are installed during spacecraft assembly and must survive launch loads, constraining their size, shape, and ultimately, effectiveness. Recent advances in on-orbit additive manufacturing have created new opportunities for shield design and deployment. This work describes the modeling and testing of additively manufactured polyetherimide shields. The finite element code CTH was used to model hypervelocity impacts (HVIs) of such shields, and though imperfect, the models were useful for shield design. Several shield designs were additively manufactured and underwent HVI testing with a two-stage light gas gun in the regime of 4 mm diameter aluminum projectile impacts at 5 - 6.5 km/s. All successfully survived the HVIs, indicating their potential effectiveness as MMOD spacecraft shielding.