Rarefied aerothermodynamic predictions for Mars Global Surveyor

Direct simulation Monte Carlo and free-molecular methods are used to provide aerothermodynamic characteristics for the Mars Global Surveyor spacecraft. These characteristics have been used for spacecraft design, mission planning, flight operations, and atmospheric reconstruction. Rarefied transitional Row effects on both heating and aerodynamic drag are shown to be significant. The spacecraft is shown to be aerodynemically stable in both pitch and yaw. The effects of a partially deployed, unlatched solar panel are also studied to provide the aerothermodynamic characteristics of a revised aerobraking configuration. The predictions show that the heating and aerodynamics of this revised configuration are not significantly different from those of the originally planned configuration. Attitude excursions observed in the early aerobraking passes are shown to be explained by significant deflections of the partially deployed panel. The predicted attitudes and panel deflections are in good agreement with flight measurements.