Evaluation of the AFRP Durability Against Debris Cloud Impacts within Multiple-Layered Bumper Shield Structures

Spacecraft shields like the Whipple bumper on ESA’s Giotto spacecraft, which explored Comet Halley, utilize lightweight composites such as Aramid Fiber Reinforced Plastics (AFRP) for effective protection against hypervelocity impacts by meteoroids and debris. While these materials have been only sporadically used over the past 40 years, due to their higher cost compared to traditional Al alloys and the capacity of larger spacecraft to accommodate heavier bumpers, recent trends to utilize smaller spacecraft such as micro-sats and cube-sats necessitate revisiting AFRP. Our studies demonstrate AFRP's superior durability within multi-layered bumpers through laboratory experiments using three-layer configurations exposed to 2-7 km/s impacts by two-stage light gas guns. AFRP layers show less damage and energy transfer, indicating better performance in dissipating impact energy than Al alloys. AUTODYN hydrocode simulations further validate these findings, showing AFRP's kinetic energy reduction per areal density to be double that of Al alloy, underscoring its higher resilience to extreme velocities and making it a preferable choice for modern spacecraft facing stringent mass constraints.