Evaluation of thermo-optical and adhesion properties of thermal control coatings employed in spacecraft surfaces

A spacecraft in orbit undergoes extreme temperature cycling due to the direct sun load on one side and deep cold space on the other side. The equilibrium temperature of any subsystem of the spacecraft is controlled by the solar absorptance (αs) and infrared emittance (ε) of its surface. White and black thermal control coatings applied to the spacecraft components play an important role on thermal control by providing suitable optical properties. In the present paper, the thermo-optical and adhesion properties of black silicone and white silicate thermal control coatings based on taguchi design were studied. Results showed that the surface pretreatment and adhesion promoter type had important influence on the adhesion properties of the black silicone thermal control coatings. The thermo-optical testing showed that solar absorbtion and emittance coefficients of this coating were 0.955 and 0.920 respectively. The results also, indicated that the pigment type was most effective parameter on the thermo-optical properties of white silicate thermal control coatings. The solar absorbtion and infrared emittance of this coating were 0.230, 0.907 respectively. Overall conclusion indicated both of optimized coatings in this study had desirable thermo-optical and adhesion properties, therefore could use as thermal control coatings on the surfaces of spacecraft.