Simulation of tether-nets for capture of space debris and small asteroids

One of the most promising techniques to capture large debris on orbit consists in the use of tether-nets. With this concept currently at a medium technological readiness level only, numerical studies on tether-net removal missions are still needed. This paper presents a versatile simulator developed with the aim of gaining insight into the dynamics of tether-net capture of space debris. Its modular architecture supports multiple modeling choices and allows simulating diverse capture scenarios with different system designs. Simulation results are shown for the capture of a realistic launcher upper stage with the representation of the main components of the system, consisting in chaser, main tether, net, and two possible configurations of a closing mechanism. It is shown that only a closing mechanism with more than one attachment to each side of the net can guarantee containment of this type of debris after capture. It is also observed that a safer capture scenario is one in which the axis of rotation of the target is parallel to the direction of ejection of the net. Additional simulation results suggest that tether-nets could be used to capture not only large debris, but also small asteroids, and that this simulator could enable future studies.