ROGER

RObotic GEostationary Robotic Restorer

ROGER concepts
A feasibility study was performed in 2002 for ESA on capturing a non-cooperative target satellite in geostationary orbit and its subsequent de-orbiting into a graveyard orbit. We were involved in the analysis of two strategies which both consisted of a chaser satellite deploying a tether, at the end of which was either a net or a robotic gripper to capture the target. The analysis allowed determining possible operating strategies for the two systems and provides insight into their dynamic behaviour.

A fundamental approach yielded a first mathematical description of the tether dynamics, while neglecting any detail of the end-element dynamic behaviour, be it that of the net or of the gripper. Further developments of this description, with supplementary experimental validation, led to a useful simulation tool of the two systems for training, analysis and design purposes.

Conceptual designs were also developed for the robotic gripper, addressing to requirements for motion stabilisation and de-orbiting of the target, thus arriving at design modifications for existing robotic hand concepts. In addition a ground control station for this type of capturing operations was conceptually designed.