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Description
Spacecraft antennas are always directly exposed to the space environment. Suitable choice of materials and processes is the basis of successful performance.
Active Antennas with very high dissipative units have to be thermally controlled in order to guarantee that the temperatures of all items will remain below the upper limits with appropriate margins. One option is to use suitable radiators. Once the radiator location and the thermal resistance between the dissipating components and the radiator are known, its size has to be determined to reject the foreseen heat dissipation. In order to maximize heat rejection of the radiator, thermal engineers choose coating materials with high emissivity. The heritage of the aerospace industry is the use of optical solar reflectors, which allow improving the heat rejection capability of the external radiators while reducing the absorption of external solar fluxes.
In the frame of an antenna thermal design of a 15-years mission in GEO environment, it was necessary to find mass-saving alternatives to OSRs, while obtaining a very efficient radiator thermal behavior. This alternative is represented by First-Flex by CREO, a new type of polyimide flexible tape developed in the frame of ARTES program, made of a multi-layer coating on the space-facing surface and characterized by low absorption (alpha) and high emissivity (epsilon).
This paper presents the comparison of the antenna thermal performance between First-Flex tape and other heritage optical solar reflectors for space applications, while also highlighting the improvement from the overall design point of view and in particular the mass reduction achieved. #
