Geostationary station-keeping with electric propulsion in full and failure modes

This paper focuses on geostationary satellites with an electric propulsion system and develops two efficient station-keeping strategies in full and failure modes. High-precision mean orbital elements are calculated by an estimator and used as the inputs of two control strategies. In the full mode, an optimization-based maneuver planner, which requires the computations of future orbits, is proposed to achieve long-term minimum-fuel station-keeping. In the failure mode, a fault detection algorithm is designed to diagnose the thruster failure and compute the orbital deviation caused by faulted thruster. Subsequently, a real-time control law as well as a threshold function is formulated to produce the on-off commands of electric thrusters, which correct the orbital deviation. Finally, numerical simulations are made to validate the accuracy and efficiency of two strategies.