A quality index for net-based capture of space debris

Before net-based debris removal missions are put in place, large simulation studies are needed to analyze the reliability of capture and define preferred designs and capture conditions. Therefore, evaluation of capture success in a simulation environment has to be automated. In this paper, a capture quality index apt to the quantitative evaluation of the success of capture is proposed. The quality index is based on volume, surface area, and distance metrics. Various parameters composing this index are analyzed in this paper, with the aim to recognize successful and unsuccessful captures reliably, starting from the moment the net is ejected to the final capture. Alpha shape was explored as an alternative to convex hull for approximating the shape of the net, but was deemed inconsistent. For the distance metrics, the reference distance was chosen as the smallest distance from the center of mass of the target to its surface. Variations in the modeling of the target were investigated. Results indicate important improvements in the performance of the capture quality index compared to previous research. The resulting quality index proves to be a useful tool to differentiate between a successful and an unsuccessful capture.