ポリイミドフィルムによる宇宙用熱制御材料の開発

抄録

Two types of thermal control materials based on polyimide film UPILEX-R are designed. One of thermal control material R/Al is coated with Al on the back surface. The other of thermal control material TCC/R/Al is coated with transparent conductive coating on the front surface and is coated with Al on the back surface.
The solar absorptance is measured spectroscopically with an integrating sphere in the wavelength region of 0.26-2.50μm and the total hemispherical emittance is measured calorimetrically in the temperature range of -100-+100°C for the present thermal control materials.
To evaluate the space degradation of optical properties (refractive index, extinction coefficient, absorption coefficient) on UPILEX-R film and solar absorptance on thermal control materials, space environment simulation tests are performed on the ground with independent radiation and combined radiation by UV, electrons, and protons. An onboard simultaneous measurement experiment with TCC/R/Al material have been carried out with a scientific satellite AKEBONO. The degradation of the ratio of solar absorptance to total hemispherical emittance have been obtained about 3 years in a space environment.
The main degradation of absorption coefficient for UPILEX-R film was obtained upon proton irradiations. For the present materials, solar absorptance was increased, and total hemispherical emittance was unaffected.