Additive Manufacture, Hypervelocity Testing, and Simulation of Polyetherimide Spacecraft Shielding

This study investigates the use of additively manufactured polyetherimide (PEI, Ultem 9085) as spacecraft shielding against micrometeoroids and orbital debris (MMOD), leveraging hypervelocity impact testing and computational simulation for both monolithic and multi-plate geometries. Because additive manufacturing enables mission-specific, potentially on-orbit shield fabrication, establishing the ballistic performance of AM Ultem across relevant velocity regimes is a critical first step. Shields were fabricated using fused filament fabrication (FFF) and subjected to hypervelocity impacts from 4-mm aluminum projectiles at 2.8–6.1 km/s. These experiments, performed at Texas A&M University’s Hypervelocity Impact Laboratory (HVIL) using a two-stage light-gas gun, were replicated with CTH shock-physics simulations matched to the test conditions. Agreement in penetration outcomes, debris-cloud morphology, and mass-loss trends across five validation shots indicates that the CTH model captures the dominant impact physics for engineering-level predictive use. Using this simulation framework, a ballistic-limit curve for monolithic Ultem 9085 was constructed for velocities from 2–8 km/s, establishing a baseline for assessing multi-plate architectures. Simulations show that two-, three-, and five-plate configurations reduce the required no-perforation thickness by approximately 13%, 17%, and 21%, respectively, relative to an equivalent-mass monolith. These improvements arise from enhanced projectile breakup and more distributed debris-cloud loading on downstream plates. Across all tested velocities, mass-savings percentages remained consistent, demonstrating that layering effects scale predictably with impact energy. Collectively, the results show that layered, additively manufactured PEI shielding provides a lightweight, tunable MMOD protection concept whose performance can be predicted with engineering-level fidelity using hydrocode tools such as CTH, supporting future mission-specific and potentially on-orbit AM fabrication.