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Description
With an estimated 130 million untrackable debris particles currently orbiting the Earth, Hypervelocity impacts pose a significant and increasing threat to spacecraft structural integrity, particularly in Low Earth Orbit (200 – 2000 km)[1]. This study focuses on small debris (1 mm to 1 cm), comprising space debris and micrometeoroids, for which evasive manoeuvres are not feasible due to their high velocities (> 7 km/s). In this hypervelocity regime, impacts impart large amounts of localised energy into the structure, leading to perforation, the generation of a dense secondary cloud of vaporised debris (or plasma due to material sublimation), and the propagation of shock waves throughout the structure. These shock waves can affect sensitive payloads and critical units, and may induce failure in structural joints, potentially leading to mission loss.
This work investigates shock generation and propagation resulting from small debris hypervelocity impacts through numerical simulations in LS-DYNA, with a primary focus on representative panel configurations and Whipple shield impact scenarios. A coupled Smoothed Particle Hydrodynamics (SPH) and Finite Element Modelling (FEM) approach has been adopted. Here, SPH has been used to model a localised region of the impacted front panel due to its superior abilities in capturing fragmentation behaviour; this region is then coupled via specifically formulated adaptive contacts to the rest of the front panel to allow for smooth, uniform shock propagation across the SPH-FEM interface. The numerical results are correlated with data (secondary debris cloud digital image dispersion and velocities, and crater dimensions measurements) obtained from two-stage light gas gun impact tests. Ongoing work involves extending the model to that of a full CubeSat-scale structural FEM to assess shock transmission across critical interfaces, including internal frames and solar array attachments. This work aims to improve spacecraft resilience to hypervelocity impacts from the early design phase through better understanding of the effects of HVI and to support the development of structural health monitoring strategies throughout the mission lifetime.
[1] European Space Agency (2025). ESA’s Annual Space Environment Report, GEN-DB-LOG-00288-OPS-SD