Rendezvous GNC-System for Autonomous Orbital Servicing of Uncooperative Targets

Abstract

The immediate future holds new challenges for spaceflight in general, and rendezvous GNC systems in particular. Space debris removal, in-orbit satellite maintenance and repair, or in-orbit assembly - all these On-Orbit Servicing (OOS) scenarios demand a reliable and safe relative approach to a so called uncooperative target object. There is no communications with this target, no precise information about its position or status and no attitude stabilization. Rendezvous is possible only by using visual relative navigation based on optical sensors. GSOC's OOS group is developing an advanced rendezvous GNC system as a research platform, for coping with these challenges. This paper describes the rendezvous GNC system and its interacting components. This includes sensors, pose estimation algorithms, navigation filter, guidance and control functions. The system's operation within the EPOS simulation environment is shown. This environment provides a high fidelity robotic Hardware-in-the-Loop simulator for the final 20 meters of rendezvous manoeuvres. With the GNC system, it carries real sensor hardware and a true-to-scale target mockup with realistic surface materials. Finally, the paper outlines the GNC system's role in the current DLR project "On-Orbit Servicing End-to-End Simulation", and concludes with the GNC system's current status and future work.