Guidance, navigation, and control experiments on the PRISMA in-orbit test bed

PRISMA will demonstrate Guidance, Navigation and Control strategies for advanced autonomous formation flying and rendezvous. The Swedish Space Corporation (SSC) is the prime contractor for the project which is funded by the Swedish National Space Board (SNSB). The project is further supported by the German Aerospace Center (DLR), the Technical University of Denmark (DTU), and the French Space Agency (CNES). PRISMA consists of two spacecraft: MAIN and TARGET. The MAIN satellite is 3-axis stabilized and has full 3D delta-V maneuverability that is independent of the spacecraft's attitude. The TARGET satellite has a simplified, yet 3-axis stabilizing, magnetic attitude control system and no orbit maneuver capability. This paper presents the PRISMA Guidance, Navigation, and Control (GNC) subsystem. The paper gives a mission summary and an overview of the GNC subsystem with its hardware and software configuration. It also explains how the orbit control functions contain advanced fuel optimal Model Predictive Control (MPC). It is shown how the GNC software is developed using model based automatic coding technology implemented with Matlab/Simulink. The paper then summarizes the different GNC experiments to be performed by SSC. Finally, an overview of the test approach for the subsystem is given.