The Docking Payload of the Ors Orbital Life Extension Vehicle

The primary objective of the Orbital Recovery System (ORS) is to provide low-cost lifetime extension for nearly fueldepleted operational geostationary telecommunication satellites. The concept is to have the ORS approach the client satellite in GEO, dock with it and provide attitude and orbit control services over a period of several year. The development of ORS is carried out as a public-private partnership, in which Orbital Satellite Services Ltd. (OSSL) has taken the lead in a consortium that has been formed by Kayser-Threde, Dutch Space, SENER and SSC. Kayser-Threde drives the brisk realization of the ambitious business case by taking prime responsibility for the Docking Payload (DP), which is a German national contribution, funded by the DLR Space Agency and KayserThrede. The Docking Payload is composed of the following components: The Capture Tool (CT) is inserted into the client spacecraft nozzle in order to capture and lock with the client, The Capture Tool Deployment Mechanism (CDM) for inserting the CT into the client nozzle, Two Camera Head Assemblies to provide stereoscopic images for vision based navigation during rendezvous and during docking of the spacecraft, The Target Illumination System (TIS) to illuminate the client during final approach, The Client Support Mechanism(CSM) for mechanical support during routine operations after the CT has been retracted and the two spacecraft are mated, The DPCU being a separate control unit for the Docking Payload. The development of the CT is under responsibility of the DLR Institute of Robotics and Mechatronics (RM), with whom Kayser-Threde has an extensive record of successful collaboration in the area of robotics and automation. Also for the development of the Payload Control Center (PCC) on ground is Kayser-Threde associated with DLR-RM. The tasks of the PCC are the monitoring and visualization of the docking maneuver, restoration of satellite relative position information from the camera images that are transmitted to ground and operator guided control of the Docking Payload. Docking maneuvers among unmanned spacecraft and a non-cooperative target satellite present an unmatched level of complexity. This implies the need for capable analysis means to derive best suitable designs for the Docking Payload itself and for the performed docking strategy. Thereto, a simulation tool has been developed, which combines orbit environmental features of traditional simulators with polygonal contact dynamics for the computation of force and torque transition during dynamic hard-docking. This simulator allows the investigation of trade-offs between different designs and of the sensitivity of the docking maneuver with respect to particular parameters and properties, along with related benefits for DP verification activities. Subsequent undertakings, aiming at verification of the Docking Payload on system level, will involve hardware-inthe-loop real-time simulation of the docking at the European Proximity Operations Simulator (EPOS) facility. For this purpose the facility will be upgraded with a high-performance robot to handle dynamic contacts among the different hardware components in a precise environment. In February 2006 the System-PDR for the Orbital Recovery System was passed successfully under the ESA ARTES 4 public-private partnership program. Currently OSSL is engaged in contract discussion with potential customers that shall lead to placement of a contract for Phases C/D/E. In Proceedings of the 9th ESA Workshop on Advanced Space Technologies for Robotics and Automation 'ASTRA 2006' ESTEC, Noordwijk, The Netherlands, November 28-30, 2006