ESA GNC Conference Papers Repository
Advanced Navigation Systems for In-Orbit Demonstration of ADR Proximity Operations
Limiting the amount of space debris is internationally recognized as a major obligation to maintain a sustainable space access in the decades to come. Actively removing 5 to 10 of heavy space debris (e.g. launcher upper stages or defunct satellites) per year is seen as the only solution to inhibit the Kessler syndrome which predicts an exponential and un-controllable growth of debris density. Therefore space agencies and industry have started investigating the feasibility of an 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 firstly discuss the challenges that the navigation function must address during an ADR mission. Then, two navigation solutions that meet most of these specifications will be described. 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 processing that provides pseudo-measurements, also fused with IMU data in the navigation filter. These two navigation solutions will be implemented on the RemoveDEBRIS demonstration mission co-funded by the European Commission, which is due for launch in 2016 and will constitute Europes first demonstration of ADR to date. This demonstration will considerably raise the Technology Readiness Level (TRL) of the navigation solutions proposed by Airbus Defence and Space and demonstrate their capabilities and performances in flight. Besides navigation, guidance and control strategies are also critical for ADR and are subject of a special focus in the final part of this paper, with a special emphasis on the critical debris towing and deorbitation phase when the debris is pulled by the chaser spacecraft through a flexible link during a sequence of deorbitation burns.