Comparison of Aluminum Alloy and CFRP Bumpers for Space Debris Protection

The important components of a spacecraft require protective shielding from space debris impact. However, shields increase the total weight of a spacecraft. Carbon fiber reinforced plastic (CFRP) is well known as a high-strength and light-weight material. The purpose of this study is to evaluate availability of CFRP bumper shields. The kinetic energies of the debris clouds generated from the bumpers were focused on. Hypervelocity impact experiments were conducted on aluminum alloy and CFRP bumpers. Based on the results of preliminary experiments, it was possible to identify the origin of a crater on a witness plate as being aluminum or CFRP by examining the crater surface. The kinetic energies of fragments in debris clouds were calculated using debris cloud images captured with a high speed camera and the results of microscopic examination of craters on witness plates. When the CFRP bumper had larger thickness than the projectile diameter, the CFRP bumper seemed to reduce the kinetic energy of debris cloud than the aluminum alloy bumper. Consequently, CFRP debris bumper is considered to show availability if debris smaller than the bumper thickness impacts on the bumper.