Noncooperative Rendezvous Using Angles-Only Optical Navigation: System Design and Flight Results

This paper presents system design and on-orbit results from the Advanced Rendezvous Demonstration using Global Positioning System and Optical Navigation (ARGON). ARGON has been conducted during the extended phase of the Prototype Research Instruments and Space Mission Technology Advancement (PRISMA) mission in April 2012. It represents one of the first rendezvous technology experiments using line of sight measurements from optical navigation and was motivated by the new generation of on-orbit-servicing and debris-removal missions which are discussed at national and international level. Its primary goal was to demonstrate the capability of an active servicer spacecraft to safely approach and rendezvous a non-cooperative passive client using angles-only optical navigation in a ground-in-the-loop fashion. To this end, a dedicated flight dynamics system has been developed for routine processing of the camera images collected on-board, for estimation of the relative orbit of the servicer with respect to the client vehicle, for maneuver planning and commanding. Despite the inherent difficulty to estimate the actual range to target through angles-only measurements and the constraints affecting the communication between ground-station and servicer, ARGON demonstrated an efficient and safe rendezvous from 30 km to the final hold point at 3 km mean separation selected before experiment start. This was possible due to the achieved relative navigation accuracy in combination with a guidance strategy based on the relative eccentricity/inclination vector separation method. As shown in the paper, the availability of independent and precise navigation information from carrier-phase differential Global Positioning System techniques gave the possibility to properly evaluate the achieved performance and cross-compare different relative navigation sensors after the conclusion of the technology demonstration.