Space Station Mir Aerodynamics Along the Descent Trajectory

Abstract

A controlled descent of space station Mir requires the choice of an optimal conŽ guration (positions of solar arrays) that allows one to minimize the disturbing aerodynamic torques and maximize the drag. An approximate approachfor choosing thepositionsbased on free-molecular analysisis developed.The aerodynamiccharacteristics of the chosen conŽ gurations are studied by engineering and statistical methods along the descent trajectory. The study showed that a decrease in the  ight altitude from 200 to 130 km does not exert a noticeable effect on the magnitude of the force and moment coefŽ cients and also revealed the reasons for the decreasing accuracy of the engineering prediction. It was shown that the gas/surface interaction model signiŽ cantly affects the torques and, therefore, the choice of the optimal conŽ guration.