Encircling Hostile Spacecraft Through Constellation Collaboration: A Differential Game Approach to Orbital Pursuit-Evasion

Recent advancements in large-scale constellation architectures provide a foundation for spacecraft clusters to effectively achieve the threat interception in the congested orbit. To address this issue, a containment-oriented collaborative interception framework for the multi-spacecraft system is designed. Firstly, a relative dynamics model capturing pursuer-evader interactions is established, anchored to the orbit threat as a reference point. An objective function incorporating a relative distance penalty term is formulated for the individual spacecraft. Subsequently, an integrated objective function is constructed and applied to all spacecraft. Secondly, the optimal interception strategies for the multi-spacecraft system are derived and simplified by identifying the sufficient conditions guaranteeing strategy uniqueness. Furthermore, the equivalence between the integrated model and the multi-agent model in terms of optimal interception strategies is rigorously proven, along with a computationally efficient solution. Finally, the effectiveness of the proposed interception strategy is validated through high-fidelity numerical simulations.