Electrical property of OSR second surface mirror in space radiation environments

Abstract

Optical second surface reflector (OSR) is widely used as thermal control coating on the surface of spacecraft. Besides its thermal physics property such as solar absorption and thermal emissivity, its electrical property such as surface resistivity is used to prevent surface charging. Under the influence of space radiation environment, the surface electrical performance of OSR secondary surface mirror will be degraded, which will threaten the on-orbit safety and reliability of spacecraft. Based on the principle of dose depth distribution equivalence and total exposure equivalence, the influence of the space electron, proton and ultraviolet radiation environments on the surface electrical properties of OSR are experimentally studied, and its performance is in situ test. It was found that the resistivity of OSR secondary surface decreased exponentially with the increase of ultraviolet exposure and irradiation of electrons and protons. This shows that the surface conductivity of the OSR secondary surface mirror in space radiation environment increases and it has a better ability to resist surface charging and discharging effects.