LAUSR

Abstract Deorbit sails are used in low earth orbit to reduce the growing amount of orbital debris by rapidly removing satellites at the end of their operational missions. However, in low earth orbit, atomic oxygen (AO) is a potential threat to long-duration exposure facilities. In this work, a multi-faceted simulation for the AO erosion of the Taurus Deorbit Sail was developed to calculate the erosion yield for the membrane material and the undercutting profile at the crease site. The disintegration and erosion detail for the deorbit sail membrane during AO impacts can be studied on an atomic scale. The ReaxFF reaction force field program is used to provide a large enough calculation speed in the size of the system to describe all the chemical reactions of the reaction. The on-orbit flight data from the Materials International Space Station Experiment 2 were used to validate the simulated erosion rate in this study. The defects on the deorbit sails were experimentally measured using a scanning electron microscope and then modeled by the Monte Carlo method. The computational predictions of AO undercutting at the defect sites were validated by experimental data from the NASA long-duration exposure facility. The disintegration of the membrane could be divided into two stages: the physical reaction stage and the chemical reaction stage, after 150 AO collisions the membrane becomes highly volatilized. The maximum undercutting depth for the deorbit drag sail within the predicted 37-month deorbit time was 5.5 μm and 7.5 μm for a defect width of 500 nm and 1 μm, respectively. The undercutting width for a deorbit sail with a width of 500 nm or 1 μm was predicted to be 1.6 μm and 2 μm, respectively, and the breaker was formed at the bottom of the undercutting profile. AO erosion has been studied by researchers in terms of evaluating the effectiveness of protective coatings. This current study, however, seeks to understand the fundamental interactions between AO and creases in the deorbit sail, which provides deeper knowledge than what has been developed so far. The multi-faceted simulation results can provide design references for engineering applications for the deorbit sail.