Secondary Arcing Triggered by Hypervelocity Impacts on Solar Panel Rear-Side Cables With Defects—Comparison With Laser Impacts

Abstract

High-velocity impacts of micrometeoroids and debris are proven causes of solar arrays power loss. Many studies have been carried out in this domain with relatively large size particles, in the range of 1 mm, causing obviously large damages, but with a small probability of occurrence. This paper deals with the occurrence of secondary arcing triggered on solar panel rear face cables with defects (lack of dielectric envelope) by smaller particles, in the range of 20– $80~\mu \text{m}$ (20 to 5 km/s), that is, with a probability of impact of several hundred of impacts by $\text{m}^{2}$ and by year both in low earth and geostationary orbits. Plasmas produced by high-velocity impacts on metallic (aluminum) and dielectric (Kapton) surfaces are characterized with a Langmuir triple probe (temperature, density, floating potential, and escape velocity). Secondary arcing tests on rear-side cables with cracks under high-velocity impacts are achieved using a solar array simulator with realistic in flight electrical conditions (120 $\text{V}^{-1}$ to 3 A). Secondary arcing tests and plasma characterization are also carried out with laser impacts (0.2 J YAG laser) and compared with high-velocity impacts.