Constrained Model Predictive Control of spacecraft attitude with reaction wheels desaturation

In this paper we propose a Model Predictive Controller for spacecraft attitude tracking with reaction wheel actuators. The controller is designed for desaturation of the reaction wheels. In contrast with standard desaturation techniques, which rely on the activation of thrusters, the proposed strategy does not need to consume fuel as it exploits external torques derived from gravity gradients and/or the Earth magnetic field. The controller also guarantees that the spacecraft attitude is constrained within specified bounds during desaturation.