State of the Art

Robotic manipulators are envisaged to be used to capture and repair satellites or remove space debris. This ambitious goal presents unique challenges and requires high levels of autonomy. Two successful technology demonstrators involving unmanned manipulator-equipped satellite have been performed so far: ETS-VII in 1997 and Orbital Express in 2007. Currently, ESA is working on the e.Deorbit mission to demonstrate active debris removal by capturing and removing the satellite Envisat while Airbus DS is developing SpaceTug. The free-floating nature of the satellite-manipulator system must be taken into account for the control of such systems. In 1989 Umetani and Yoshida proposed a resolved rate and acceleration control based on the new Jacobian matrix in generalised form for satellite-manipulator systems. More recently it was presented a control-oriented dynamic modeling framework for constrained multibody systems, which was applied to free-floating satellite-manipulator systems. In addition to autonomous robotics, proximity navigation to a non-cooperative orbiting object is one of the key technologies required to realise on-orbit-servicing (OOS) and active debris removal. The navigation system has to identify the target, estimate its relative motion from far-range to close-range distance, and provide full translational and rotational motion, mass and inertia parameters estimation. For cooperative scenarios the NASDA ETS-VII and DARPA Orbital Express missions already demonstrated OOS. The PRISMA formation flying test-bed performed a wide range of proximity activities, reaching an inter-satellite distance below 1m, using relative GPS metrology and a monocular close-range camera system. The AVANTI experiment showed that the inspection-range region around a noncooperative target can be safely achieved, relying solely on line-of-sight observations from a monocular far-range camera sensor, even in harsh environments. The AFRL XSS (Experimental Spacecraft System) program, with the XSS-10 and 11 endeavours, performed on-orbit inspection of noncooperative rocket bodies with high levels of autonomy. Current and future projects mainly address noncooperative scenarios, to apply OOS to satellites not designed to be serviced or damaged (e.g., NASA Restore-L), as well as active removal of debris (e.g., e.Deorbit, RemoveDEBRIS, CleanSpace One). For such projects close-range relative navigation systems exploiting sensor data-fusion, in line with the H2020-PERASPERA programme, is a key enabling technology. Multi-sensors’ close-range relative navigation systems demand for the development of dedicated algorithms, with special focus on embedded solutions for Low Earth Orbit.

Objectives

WP6 covers all activities related to robotics and the required autonomy to perform rendezvous, docking, on orbit servicing, repair and disposal. It includes the use of specific removal technologies that require and interaction between a cooperative and a non-cooperative object.

Research Output

PelayoPenarroya, Shubham Vyas, Roberto Paoli, Karl Martin Kajak. Survey of Landing Methods on Small Bodies: Benefits of Robotics Manipulators to the Field. In International Symposium on Artificial Intelligence, Robotics and Automation in Space, (iSAIRAS-2020), 19.10.-23.10.2020, Online, n.n., Oct/2020 (poster).

Christian Ernst Siegfried Koch, Marko Jankovic, Sankaranarayanan Natarajan, Shubham Vyas, Wiebke Brinkmann, Vincent Bissonnette, Thierry Germa, Alessio Turetta, Frank Kirchner. Underwater Demonstrator for Autonomous In-Orbit Assembly of Large Structures. In Robotics and Automation in Space 2020, (i-SAIRAS-2020), 19.10.-23.10.2020, Online, n.n., Oct/2020 (conference paper).

Shubham Vyas, Marko Jankovic, Frank Kirchner. Momentum Based Classification for Robotic Active Debris Removal.In 71th International Astronautical Congress, (IAC-2020), 12.10.-14.10.2020, Online, International Astronautical Federation (IAF), Oct/2020 (conference paper).