A synergetic control scheme for tether tugging deorbiting with attachment points switching

Abstract

The accumulation of space debris in orbit poses significant challenges, consuming limited orbital resources and threatening the safe operation of active spacecraft. For GEO orbits, where natural debris removal mechanisms are virtually absent, active debris capture and removal technologies have become imperative. Existing methods face significant obstacles in achieving effective tether-tugging of space debris, largely due to the underactuated characteristics of tether control and the dynamic changes in traction points when tether nets are used to enclose and tow debris targets. During the towing process, traction points may switch as a result of local tightening and loosening of the net, further complicating the stabilization of the system. To address these challenges, this paper proposes a synergetic multi-channel control scheme that incorporates traction point switching dynamics into the framework of tether-tugging operations. By integrating attitude, orbit, and tether deployment/retrieval controls, the proposed scheme ensures stable and efficient deorbiting, providing a reliable solution for transferring high-altitude debris to graveyard orbits. Numerical simulations of the entire deorbiting process are conducted to validate the feasibility and effectiveness of the proposed approach.