Spacecraft System-Level Survivability Assessment Method Considering Secondary Debris Cloud Damage

Space debris and micrometeoroids have become one of the sources of risk for the safe operation of spacecraft in orbit. Damage caused by impacts at different velocities is inconsistent. Particles fragment upon non-low-velocity impact, forming a debris cloud that can damage internal components. This paper establishes a hypervelocity impact vulnerability assessment model of internal spacecraft components based on the debris cloud model (DCM). By integrating the DCM and ray-tracing method, the deficiency of the ballistic limit equation method in describing the damage effects of secondary debris on internal components is addressed. This integrative model ensures more accurate computations and achieves a more realistic simulation of internal component vulnerabilities during the hypervelocity impact vulnerability assessment process. Building on this model, a spacecraft system-level survivability assessment method based on dynamic Bayesian networks is proposed, taking into account the possibility of common cause failures (CCFs) induced by secondary debris clouds. This approach removes the assumption that component failures are independent, which is inherent in previous non-CCF models. The results indicate that the use of a non-CCF model can adversely affect the survivability assessment of the system, leading to suboptimal redundancy design.