Assembly and Testing of a Thermal Control Component Developed in Brazil

Abstract

The optical solar reflector is basically a mirror of second surface with low absorptivity/emissivity ratio and negligible degradation in the space environment, which makes it an excellent coating for thermal control of satellites. It works as a radiator and is used in particular parts of the external surfaces of the satellites in order to reject the undesirable heat to the deep space. In the Brazilian Space Programs, the radiators of the satellites are generally painted with special white paints in order to reject heat instead of the use of optical solar reflector. The problem of white-ink radiators is the high degradation of the thermo-optical properties that happen over the useful lives. Thus, a process of manufacturing and assembly of optical solar reflector was developed in Brazil. To validate this process in terms of mechanical and thermal properties, 3 types of optical solar reflector radiators were manufactured, and their absorptivity and emissivity properties at the temperature of 23 °C were measured. Optical solar reflector coupons were mounted on aluminum plates to perform vibration, thermal vacuum and thermal-shock tests. A study was also done to optimize the thickness of the glue to fix the structure of the satellite on the optical solar reflector. It showed an excellent environmental stability and maintained its thermo-optical characteristics after the tests.

Keywords

• Solar radiator
• Satellite Thermal Control
• Solar absorptivity
• Emissivity.