Space Robotics Technologies for On-Orbit Servicing Missions

Authors (tentative): Iosif S. Paraskevas, Georgios Rekleitis, Kostas Nanos, Olga Christidou, Sabrina Andiappane, Evangelos Papadopoulos


A safe and secure space environment is a requirement for all current and future space activities. To contribute to space sustainability, some Agencies and Governments have established or adopted policies to mitigate space debris creation. As a consequence, a new generation of services, namely the On-Orbit Services (OOS), have been envisioned, which indicatively include the replacement of malfunctioned components (using Orbital Replacements Units ORUs), refueling of fuel-depleted satellites, and Active Debris Removal (ADR). To this end, the Control Systems Lab (CSL) in coordination with Thales Alenia Space in France (TASF) implements three key projects.

The first is the European Project EROSS (European Robotic Orbital Support Services), which is co-funded by European Union’s Horizon 2020 research and innovation program under grant agreement N°821904 and part of the Strategic Research Cluster on Space Robotics Technologies as Operational Grant n°7. Its objective is to demonstrate the European solutions for the Servicers and the Serviced LEO/ GEO satellites, enabling a large range of efficient and safe orbital support services. The project assesses and demonstrates the capability of an On-Orbit Servicing spacecraft (Chaser) to perform rendezvous, capturing, grasping, berthing and manipulation of a collaborative client satellite (Target) provisioned for servicing operations including refueling and payload transfer/ replacement. EROSS embeds key European Technologies by leveraging on actuators, sensors, software frameworks and algorithms developed in previous European Projects. EROSS boosts the maturity of these key building blocks and increases their functionalities and performance in a coherent work program targeting fast and practical deployment of the developed solutions in space. The consortium went into great details in the EROSS concept and the technical operational plan to manage perfectly the risks and complexity of development of such a large system. EROSS wants also to enable extended markets by proposing additional features to cover more complex space robotics operations like orbital servicing of non-collaborative and non-equipped satellites.

Two other programs, where CSL and TASF collaborate, which are considered as important building blocks for OOS, are the ESA’s OBSIdian (On-Board System Identification for Uncertainty Modelling & Characterization) and the ESA’s PRINCE (Passive Mechanical and Rendezvous Interface for Capture After End-of-Life). The main objective of OBSIdian is to develop where necessary and to apply, numerically efficient system identification techniques to space systems, in order to obtain dynamical mathematical models for space systems and control purposes. Beyond applying system identification as first objective, system identification shall be studied in combination with control. The control and identification tasks to be elaborated shall be viewed for increasing system dynamics and architecture complexity. The goal is to enable the use of more complex robotics scenarios in the future for OOS tasks. On the other hand, the main objective of PRINCE is to design and verify (up to TRL 3) a mechanical interface with integrated rendezvous/ navigation aids which enables the safe capture and removal of a non-operational/ non-cooperative satellite for uncontrolled re-entry; hence the focus of PRINCE is the ADR missions.

During this presentation, an outline of the main results up until now will be presented, while the focus will be given to EROSS, which deals with the most critical issues of such missions. In particular, a presentation of the necessary coordinated and impedance control schemes to be used in such missions will be given. Concepts for system identification and how these methods can be integrated in an OOS mission will be shown. Design approaches will be also presented. Finally, details will be given for the CSL’s experimental facility (Space Robotics Emulator – SRE), which will be used in all these three projects.


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The project has received funding from the European Union’s Horizon 2020 Research and Innovation  Programme under Grant Agreement No 821904