Analysis of the concept of non-cooperative targets and associated tailored Active Debris Removal methods

Related to the Kessler syndrome and associated research, the number of space debris is increasing and to make the space environment stable, about 5-10 large debris objects should be removed from space each year. In most cases, space debris objects are non-cooperative targets which bring a massive challenge for capturing and de-orbiting. The objective of this paper is to critically research various levels of non-cooperativeness and define their characteristics, then assign the ADR (Active Debris Removal) methods to the different debris objects. We have grouped non-cooperativeness in terms of knowledge and capturability. Lack of knowledge leading to non-cooperativeness can be due to orbit and attitude information, physical properties, such as moments of inertia, or size, shape and surface properties. Non-cooperativeness in terms of capturability can be related to, e.g., possible docking locations, known but high spin rates or tumbling. Following such a classification, we have mapped existing ADR methods to those classes of non-cooperativeness. We analyzed the usability of classification. The results not only allowed us to show the usability of out metrics, but also enable us to propose so-far unexpected approaches for ADR. Details of the results are presented in the paper.