Sub-millimeter Debris Impact Damage of Unmanned Spacecraft Structure Panel

Abstract

This study investigated the damage caused by sub-millimeter debris impact on the structures of unmanned spacecraft owing to the increase in the amount of sub-millimeter debris in the low earth orbit. Panel structures are mainly made of honeycomb sandwich panels, and the chassis of electronic devices are mounted on the panel. Because damage to the electronic device strongly influences the mission success of a spacecraft, determining the damage to the chassis wall behind the structure panel is important in debris protection design. Hypervelocity impact experiments were performed on the sets of an aluminum honeycomb sandwich panel and an aluminum alloy plate. The aluminum alloy plate was installed behind the honeycomb sandwich panel, without a standoff distance. In the experiments, sub- millimeter steel spheres (diameters of 0.15-1.0mm) were accelerated up to 6km/s by a two-stage light gas gun. Impact angles were varied from 0° to 30°. The depths of craters on the aluminum alloy plate were measured after the impact. A crater depth equation that applies when impact angles are less than 16.1° was calculated empirically.