Study of a rotating tethered system for capturing large-sized space debris on intersecting courses

The capture of the space debris (SD) occurs after the tether is delivered from the space tug (ST) to the SD with the help of an autonomous docking module (ADM). During tether stretching, motion impulses are exchanged between the ST and the "ADM + SD" system, after which a rotating space tether system (RSTS) is created.

Under the influence of two factors, i.e., the difference in relative velocities of the ST and the "ADM + SD" system (up to 200 m/s) and the centrifugal force, significant longitudinal deformations of the tether occur, which can lead to its breakage. The presence of a significant value of the relative velocity projection on the tether line is the peculiarity of this RSTS which has a significant effect on the tether loading in comparison to the action of centrifugal force. In traditional RSTS, only centrifugal forces are considered.

This paper introduces a novel method of damping the longitudinal oscillations of the tether for the proposed type of RSTS, based on two active control strategies: by changing the natural length of the tether and by the thrust force of the ST propulsion system acting opposite to the centrifugal force. A comparative analysis of the dynamics of the RSTS under different methods of active control has been performed.

Significance of the developed methodology is determined by the possibility of using it for further research in planning various active interorbital space missions. The contribution to the solution of the problem under study consists of the possibility of creating RSTS formed by exchanging the impulses of the ST motion and the "ADM + SD" conjunction at significant relative velocities, unlike traditional RSTS, such as star, triangle, etc.