Characterisation of rear incident hypervelocity impact phenomena on Hubble Space Telescope solar arrays

Impact damage on glass faced HST solar cells generated by rear-incident impactors represent over one-third of the total damage on the retrieved solar array. Analysis of such space and laboratory generated morphologies has revealed a means of discriminating between front and rear incident impact sites and enabled characterization through either impactor energy or a simplified indentation fracture model. Morphology is seen to evolve with impactor energy and incidence. Onset of rear incident penetration occurs at one-third of the particle size necessary for front incident. Calibration of rear incident particle flux-size is possible using this approach.