Long-Term Collision Risk Assessment of Spacecraft Based on Three-Dimensional Space Grid

To achieve accurate and efficient analysis of the evolution of large amounts of space debris, this paper integrates fluid mechanics and orbital dynamics to explore the evolution mechanisms of space debris under the influence of gravitational and perturbation field couplings. The continuous factors, such as atmospheric drag and J2 perturbation, as well as discontinuous factors, like launches and post-mission disposal of satellite, are quantified appropriately. A space debris evolution model is established based on the continuity equation in fluid dynamics, enabling fast and precise predictions of the space debris environment at any time and location. Based on this model, hazard levels in different space regions are classified, and the collision risks for spacecraft during operation are analysed.