Modeling Hyperthermal O-Atom Scattering Dynamics on Satellite Materials

This study evaluates the performance of widely used gas-surface interaction (GSI) models in reproducing the scattering dynamics of hyperthermal (∼5 eV) oxygen on satellite surface materials. We benchmarked four different models against recently published molecular beam-surface scattering data and macroscopic energy accommodation estimates for two materials: fluorinated ethylene propylene (FEP) polymer and aluminum with an Alodine chromate conversion coating. Our analysis revealed that existing models, including the best-performing washboard model, failed to accurately capture both the angular dependence of the scattered product flux and translation energy. To address these limitations, we developed a generalized roughness model within the washboard model framework that represents anisotropic surfaces. This new model demonstrated improved agreement with experimental flux distributions and reproduced macroscopic quantities across all incident angles successfully with a single set of input parameters. These results reveal that existing GSI models are not able to model scattering for low Earth orbit conditions and show that the new model can provide more reliable predictions for satellite aerodynamics in these environments.