Reflective thermal control coating for spacecraft based on ZnO pigment and Li2SiO3 silicate modified by SiO2 nanoparticles

Abstract

Studies on the optical properties and radiation resistance of thermal control coatings for spacecraft based on zinc oxide pigments (nSiO2 3 wt %) and lithium silicate binder (nSiO2 0.5 wt %) unmodified and modified by SiO2 nanoparticles are presented. Experiments demonstrated that thermal control coatings based on nanoparticle-modified components exposed to electron irradiation (energy E = 30 keV, fluence F ≤ 7·1016 cm−2) have higher resistance in terms of diffuse reflectance spectra and solar absorptance (αs) as compared to other coatings. The prediction of degradation under exposure to an electron spectrum in a geostationary orbit showed a significantly higher radiation resistance of the thermal control coatings based on modified components. The difference Δαs was 1.54, 1.74, 1.88, and 1.95 for 5, 10, 15, and 20 years of electron irradiation, respectively.