Contact dynamics modeling and simulation of tether nets for space-debris capture

A proposed method for containing the growth of space debris, which jeopardizes operation of spacecraft, is the active debris removal of massive derelict spacecraft and launcher upper stages by means of tether nets. The behavior of nets in space is not well known; therefore, numerical simulation is needed to gain understanding of deployment and capture dynamics. In this paper, a lumped-parameter approach for modeling the net and different models of contact dynamics are presented. A continuous compliant approach for the normal contact force and a modified damped bristle model for the friction force are chosen. The capability of the developed simulation tool to represent multiple dynamic conditionsis demonstratedin this paper, and the resultsofa deployment dynamics simulation are presented; this reveals a snapping behavior of tension. Simulation of net-based capture of cylindrical debris in microgravity and vacuum conditions isperformed with the presented tool. The effect ofemploying different contact force models on the overall results of captureis evaluated, both from adynamical and acomputational pointofview, and reasonsto prefer nonlinear models are discussed.