Autonomous Satellite Servicing Using the Orbital Express Demonstration Manipulator System

The Orbital Express Demonstration System (OEDS) flight test, flown from March to July 2007, achieved all of its mission objectives, demonstrating a suite of capabilities required to autonomously service satellites on-orbit. Demonstrations were performed at varying levels of autonomy, from operations with pause points where approval from ground was required to continue, to fully autonomous operations where only a single command was sent to initiate the test scenario. The Orbital Express Demonstration Manipulator System (OEDMS), mounted on the ASTRO spacecraft (chaser), was used to service the NextSat spacecraft (client satellite). The OEDMS played a critical part in achieving two key goals of the OEDS flight test: autonomous capture of the free-flying NextSat and autonomous ORU (On-Orbit Replaceable Unit) transfer. This paper describes the OEDMS vision system and arm control visual servo capabilities, key enabling technologies for autonomous capture of the free-flying NextSat with a robotic manipulator. Features of the ORU transfer system, such as standardized non-proprietary interfaces for handling and attachment, are discussed. Finally, sample flight telemetry is presented.