Improved Method for Estimation of Spacecraft Free-Molecular Aerodynamic Properties

摘要

A numerical procedure for calculating free-molecular aerodynamic properties of spacecraft is revisited andnredeveloped using improved discretization and shading techniques. New complex geometric shapes are included,nallowing the user to model a high-fidelity spacecraft model divisible into elemental panels of approximately equalnarea to conserve resolution. The forces on exposed elements are summed across the entire geometry. New analyticnmethods for determining exposed panels have been developed. Combined with the use of array algebra, thenimprovements considerably enhance processing speeds. The fidelity of the data is tested by application to thengeometry of theMarsReconnaissanceOrbiter. The resulting data are comparedwith direct simulationMonte Carlonpredictions. Additional case studies serve to inspect implications of geometry design versus output accuracy andnprocessing speed.