Extending the ECOB space debris index with fragmentation risk estimation

In recent years several formulations of debris indices have been proposed to provide a fast assessment of the criticality of a space object in terms of its impact on the debris environment. In a previous work, we proposed a formulation (ECOB, Environmental Consequences of Orbital Breakups) based on the evaluation of the consequences of the fragmentation of the studied object in terms of the increase in the collision probability for operational satellites. This work discusses the extension of that approach by considering not only the effect of the fragmentation but also its likelihood. In addition, a method to take into account different End-of-Life scenarios and the application to constellations are discussed.