Background and justification: Space environment includes severe radiation and plasma storms - driven by solar activity and its effect on the Earth’s magnetosphere – affecting satellite systems.

The objective of the Landmark ClearSpace-1 mission will be to demonstrate the complete value chain of active debris removal by removing an ESA-owned object (a VESPA upper part orbiting at an altitude of 500 km) by 2025.

At present, the largest part of the catalogued space debris population consists of fragments originating from accidental explosions of spacecraft and upper stages, but it is expected that hypervelocity collisions involving large objects could become the primary source of new debris in the mid-term future. In this context, understanding the physical processes involved in spacecraft collisions is crucial, because these big impacts are one of the key drivers of the long-term evolution of the amount of space debris.

Resulting from an ever increasing public pressure, the quest to be environmentally friendly is transforming the competitive landscape, as eco-friendly design results in a new frontier of innovation. As a public sector intergovernmental organisation, ESA is committed to prioritising environmental concerns in all its activities. Through its Clean Space initiative, the Agency is pioneering an eco-friendly approach to space activities.

The technical objective of this study was to understand the net effect of using deorbiting technologies like sails or tethers over the future debris population around Earth. In principle, indeed, these attractive technologies will support the compliancy to post-mitigation disposal guidelines, for small missions. However, the increased cross section also increases the collision risk.

Establish a reference ion data set and improve the Solar Energetic Particle Environment Modelling (SEPEM) model to include better prediction of ion composition and energy spectra, and transport across the geomagnetic field. This will include the ingestion of new data sets, the quality control and cleaning of the data (de-spiking, gap filling, saturation compensation, etc.), the interpolation to required energy values and augmentation with LET (Si, GaAs) values.

The increase of space debris means that active space debris removal is becoming more relevant. An active debris removal mission would have a positive effect (or risk reduction) for all satellites in the same orbital band. This leads to a dilemma: each space agency has an incentive to delay its actions and wait for others to respond. We model this scenario as a non-cooperative game between self-interested agents in which the agents are space agencies.