Passivity-based attitude control of the SSETI ESMO satellite

In this paper we present a study of the Attitude Control System (ACS), based on reaction wheels and thrusters for the Student Space Exploration Technology Initiative (SSETI) European Student Moon Orbiter (ESMO) using a passivity based sliding surface controller called Slotine & Li. The ACS includes four Reaction Wheels (RW s) in a tetrahedral configuration and four Attitude Control Thrusters (ACTs). The RWs will mainly be used for orienting of the satellite and de-tumbling, while the ACTs will be used for momentum dumping of the RWs. A Slotine & Li controller is derived, which is applied on the reaction actuators on ESMO where it is proven stable using Lyapunov theory, and controller performance and reliability, together with overall system pointing accuracy is shown via simulation using MATLAB.