GNC Challenges and Navigation Solutions for Active Debris Removal Mission
Active removal of large space debris has been identified as a key mission to limit growth of debris jeopardizing missions of active satellites. In particular, orbits of economic and strategic importance, Low Earth Orbits, are pervaded with objects such as upper stages of launchers or defunct satellites: collision between large debris has become a likely event in the next five years according to simulations done in Space Agencies. Willing to anticipate such event and limit collision risk, Agencies and industrials investigate feasibility of Active Debris Removal (ADR) mission. Many critical points have yet to be solved, such as legal aspects, cost, debris to be removed and technological challenges to successfully complete the mission. This paper will first initiate a discussion around challenges that has to face the Guidance, Navigation and Control (GNC) sub-system during the ADR mission. Then, two navigation solutions that meet most of navigation challenges for ADR mission will be introduced in this paper. The first solution relies on an active, 3D camera, fused with IMU data in a navigation filter. The second solution relies on a passive, 2D camera and a state-of-the-art Image Pro-cessing that provides pseudo-measurements, also fused with IMU data in the navigation filter.