Performance Assessment of a Gyroless 3-Axis Stabilised Sun Pointing Mode on a Highly Elliptical Orbit

This paper investigates the feasibility of a concept for acquisition and maintenance of a gyroless three-axis stabilized Sun pointing attitude from tumbling conditions on a Highly Elliptical Orbit (HEO) in the presence of sunlight, based on the sole utilisation of Sun sensors and reaction wheels. It uses the ESA PROBA-3 mission as a study case. Based on candidate algorithms identified in the literature, suitable Guidance, Navigation, and Control (GNC) functions are designed to meet the PROBA-3 Sun Acquisition Mode pointing requirements. The proposed GNC loop is validated in a high fidelity closed-loop simulation environment and is found to be reliable provided observability conditions are met. These conditions and other limitations are discussed.