Abstract

Subject of the study. The subject is the design of an optical solar reflector that will provide high integral reflectance (over 98% within the 350–2500 nm wavelength range) and low absorption (0.041 maximum). Purpose of the work. The purpose is the development of interference-coating-based optical solar reflectors for heat removal and reflection of solar radiation from spacecraft, which will improve their performance and longevity. Method. The optical solar reflector was designed via the synthesis of multilayer interference structures and the selection of film-forming materials resistant to high temperatures since optical solar reflectors must withstand maximum spacecraft hull surface temperatures of 1260°C–1454°C. The spectral characteristics of the structures were calculated using matrices. The resulting interference-mirror designs with layers of metal and layers of various refractory oxides increase the reflection coefficient of radiation in the operating spectral range by choosing the thickness of the layers that make up the dielectric component of the mirror. Main results. A dielectric mirror can be used to increase the ultraviolet reflection coefficient of an optical solar reflector that includes a silver mirror by 18%. Calculations indicate that our optical solar reflector design reduces the principal characteristic—the solar absorption coefficient—from 0.049 (the value for pure silver) to 0.041 for optical solar reflector systems that include silver layers and from 0.114 (the value for pure aluminum under the condition of total internal reflection) to 0.081 for a system that includes dielectric layers. The practical significance lies in solving the problem of spacecraft thermal control and reflection of solar radiation by spacecraft/aircraft, which is important for improving their performance and longevity.

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