Design of a novel deployable mechanism for capturing tumbling debris

Large quantities of man-made debris from decades of space exploration threaten the safety of future space activities. It is therefore urgent to perform active debris removal missions to maintain access to usable orbital space. This paper proposes a novel deployable end-effector and detumbling mechanism to capture tumbling debris. Three mechatronic subsystems for capture, transmission, and actuation are highly integrated in the end-effector, allowing compact storage during space transport. Grippers composed of constant-torque hinges endow the mechanism with a deployable function and ensure a steady envelope by means of caging, without the need for precise tracking and complex control. With only one actuator, simultaneous motion of the six grippers is implemented by arranging gears in a unique manner. The grippers are optimally designed to enlarge their envelope while reducing weight. A contact detumbling mechanism, composed of three dampers along three axes, is also provided based on revolute friction to slow tumbling debris with residual angular momentum. Two slip rings are ingeniously embedded in each damper to transmit electricity under conditions of signal interference and cable interwinding. Simulations of capturing and detumbling demonstrate the feasibility and effectiveness of the proposed mechanism.