Effect of simultaneous N2 collisions on atomic oxygen-induced polyimide erosion in sub-low Earth orbit: comparison of laboratory and SLATS data

The role of N2 in the upper atmosphere on the atomic oxygen (AO)-induced erosion of polyimide in low Earth orbit (LEO) and sub-LEO is investigated through ground-based experiments and flight data. The experiment is performed by adding an Ar beam at the same collision energy as an undecomposed O2 component in the AO beam formed by laser detonation to simulate the physical effect of simultaneous N2 collision in sub-LEO. The Ar beam is added by the dual-pulsed supersonic valve-equipped laser-detonation system developed at Kobe University. The experimental results indicate that the erosion of polyimide in the laser-detonation system is promoted by the presence of O2 and Ar in the beam, corresponding to N2 in the sub-LEO. On-ground experimental results are compared with in-orbit AO measurements. Previous space shuttle, international space station-based exposure experiments, as well as the world’s first real-time sub-LEO material erosion data aboard a super low altitude test satellite (SLATS) orbiting at an altitude of 216.8 km are presented. The SLATS data suggests the presence of an acceleration effect by N2 collision on AO-induced polyimide erosion, as predicted by ground-based experiments.