Assessing the Impact of a Space Mission on the Sustainability of the Space Environment

Space, like any other ecosystem, has a finite capacity. The continuous growth of space activities is contributing to overload this delicate ecosystem. In this paper, the THEMIS software tool will be presented, conceived to assess the impact of a space mission on the space environment and its contribution to the overall Space capacity. THEMIS is developed by Politecnico di Milano and Deimos Space within an ESA-funded study. A density-based approach is used for propagating the fragments originating from collisions and explosions in space. This is used in the definition of a debris index to assess the impact of a space object on the environment, based on mission information such as its orbit, mass, cross-section, and risk of fragmentation due to accidental collisions or break-up. The output of the environmental analysis is summarised into a single score, which is integrated in the ESA database DISCOS for reporting analyses and which is also suitable for integration into a life cycle assessment procedure.