Space Robot Dynamics and Control: To Orbit, From Orbit, and Future

Abstract

The Engineering Test Satellite VII (ETS-VII), launched by National Space Development Agency of Japan (NASDA) on November 1997, has been successfully flown and carried out a lot of interesting orbital robotics experiments with a 2 meter-long, 6 DOF manipulator arm mounted on this un-manned spacecraft. The ETS-VII should be noted as one of remarkable outcomes of research effort on space robots, particularly characterized as a orbital free-flying robot which concept was brought in early 80s. This paper provides overview and summarize the ideas around dynamics and control proposed for such a free-flying space robot and what has been recently tested and verified on ETS-VII. The ETS-VII flight mission is an important milestone, but not a goal. The goal will be robotic service to satellites in orbits, including an emerging number of communication satellites spreading out to the low-earth orbital networks or constellations. Which aspect of technology is now verified and which is left over for future satellite servicing are also discussed.