Re-entry trajectory tracking control of a micro-satellite system with a deployable front structure

This paper is focused on the design of a Model Predictive Control (MPC) algorithm for a micro-satellite with a mass of about 20 kg, equipped with an umbrella-like deployable front structure. This control device allows the vehicle to maneuver and track a prescribed trajectory during the re-entry phase by changing the aerobrake surface. The proposed MPC controller is aimed at minimizing the error between the desired target position at an altitude of about 30 km, after which the satellite follows an uncontrolled ballistic trajectory. A single control move is updated at a sampling rate of 0.1 Hz trying to balance performance with computational burden for a possible real time implementation. To prove that the proposed MPC strategy implies a limited loss of performance, a comparison with MPC controllers optimizing more than one control move has been carried out.