High-temperature solar reflector coating for the solar orbiter

SolarWhite is a diffusely reflective (white) inorganic thermal-control surface tailored for use in high-temperature environments, including European Space Agency's Solar Orbiter mission. The material is applied via a liquid spray process to substrates including, but not limited to, titanium and aluminum alloys and requires a multistage thermal curing cycle. This coating is required to exhibit long-term thermal/thermo-optical stability under extreme ultraviolet, vacuum-ultraviolet, proton, and electron radiation while possessing the electrical conductivity necessary to prevent surface arcing or internal electrostatic discharge in service, with specific requirements for the Solar Orbiter mission. This paper presents the results of the early ultraviolet/vacuum-ultraviolet-stability testing, carried out in the second Synergistic Temperature-Accelerated Radiation facility space environment simulator at the European Space Technology Centre; the outgassing characteristics of the surface have previously been examined using residual gas analysis. Material characterization was carried out using scanning electron microscopy, ultraviolet/visible/nearinfraredspectroscopy, and infrared spectrometry.