Design Contributions to the Attitude Control System of a Geostationary Satellite

Abstract

The influence of Earth's gravity and lunar-solar disturbances can cause a geostationary satellite to deviate from its intended position. To counteract this, periodic station-keeping maneuvers are necessary. These maneuvers depend on the attitude control system to maintain stability and ensure the satellite's antenna remains directed towards the Earth station, ensuring mission services. This paper presents a design contribution to the attitude control system of a geostationary satellite, specifically during north-south station-keeping maneuvers. To effectively manage the satellite's position within a designated station-keeping box and control its attitude in three axes, a minimum of six 10 N chemical thrusters is required. The thruster configuration is designed to calculate torque parameters by considering the thrust vector, satellite mass, and the forces and moments acting upon them. The satellite model used in this study includes a rigid satellite dynamics model, perturbation model, PD controller, pseudo-rate modulator, and logic thruster selector. Once the system design is complete, numerical simulations can validate its performance and effectiveness. The simulation results confirm that all requirements have been met and the station-keeping design has been successfully implemented.