Space Station Mir Aerodynamics Along the Descent Trajectory

A controlled descent of Space Station Mir requires the choice of an optimal configuration (positions of solar arrays) that allows one to minimize the disturbing aerodynamic torques and maximize the drag. An approximate approach for choosing the positions based on free-molecular analysis is developed. The aerodynamic characteristics of the chosen configurations are studied by engineering and statistical methods along the descent trajectory. The study showed that a decrease in the flight altitude from 200 to 130 km does not exert a noticeable effect on the magnitude of the force and moment coefficients and also revealed the reasons for the decreasing accuracy of the engineering prediction. It was shown that the gas/surface interaction model significantly affects the torques and, therefore, the choice of the optimal configuration. (Author)