HST solar array impact survey: Revised damage laws and residue analysis

This report presents results of the analysis of impact features on the retrieved Hubble Space Telescope (HST) solar array and compares them to similar data from EURECA. The post-flight meteoroid/debris investigation programmes included optical surveys of all outer surfaces, impact residue analyses and hypervelocity calibration tests on MLI and solar array samples. Observed crater sizes range from about 2 μm to 6–7 mm. On the HST solar array impact fluxes at the same crater pit diameter are higher than for EURECA for sizes exceeding about 200 μm while they are comparable for smaller sizes. Impact fluxes on EURECA and HST do both exceed the 6 face averaged fluxes on LDEF. The residue analyses which were performed for EURECA MLI and HST solar array samples proved very difficult due to the complexity of the targets and they produced somewhat inconclusive results. Some results of hypervelocity impact calibration tests are presented. A comparison between the measured impact data and the predictions of present flux models is given.