Analysis of submillimetre fragments generated by high-velocity impacts of a picosatellite mock-up

The fragmentation behaviour of satellites under hypervelocity impacts remains insufficiently quantified at the fragment scale relevant for debris environment modelling. This study presents an advanced post-test characterization of debris produced by two high-velocity impact experiments on a small satellite mock-up, with emphasis on three-dimensional geometry, mass, and shape properties of individual fragments. The tests, previously conducted at the Hypervelocity Impact Laboratory of the University of Padova, involved a normal impact and a 45 deg glancing impact at energy to mass ratios exceeding the catastrophic fragmentation threshold. All recovered fragments, including those smaller than 2 mm, were individually measured using high-resolution mass instrumentation and geometric reconstruction techniques, resulting in a catalogue of 1735 debris items. Fragment characteristic lengths were computed following the “right circular cylinder” (RCC) approach adopted in the NASA DebriSat program, allowing the derivation of cumulative size and mass distributions. The obtained mass size correlations are consistent with established fragmentation scaling laws, while demonstrating sensitivity to material composition and impact geometry. Analyses of area to mass ratio and shape categories reveal systematic discrepancies with NASA EVOLVE predictions for small debris, particularly in the prevalence of elongated fragments. These findings provide new experimental evidence to support the improvement of fragmentation and debris environment models for modern small satellites.