Passive Aerodynamic Stabilization of a Low Earth Orbit Satellite

This paper discusses the influence of aerodynamic drag torque on the dynamics of a satellite in a very low altitude orbit. The larger atmospheric density in low altitude earth orbits results in significant aerodynamic drag torques acting on the satellite. With a conventional satellite design this may result in instability. This paper shows how the instability can be avoided, and how the aerodynamic drag can be used for passive attitude stabilization of a satellite with an appropriate geometry. Design recommendations and tradeoffs are presented for the use of aerodynamic drag in attitude control. The results have been applied on a ESA study satellite required in an orbit with less than 250 km altitude. Simulations and analytical results indicate that the satellite will oscillate between two attitude equilibria. Performance of a basic attitude control algorithm providing stable satellite motion is given.