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, e ight operations, and atmospheric reconstruction. Raree ed transitional e ow effects on both heating and aerodynamic drag are shown to be signie cant. The spacecraft is shown to be aerodynamically 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 cone guration. The predictions show that the heating and aerodynamics of this revised cone guration are not signie cantly different from those of the originally planned cone guration.Attitudeexcursionsobservedintheearlyaerobrakingpassesareshowntobeexplainedbysignie cant dee ections of the partially deployed panel. The predicted attitudes and panel dee ections are in good agreement with e ight measurements.