Development of Deployable Reflector Antenna for the SAR Satellite: Part 4—Thermal Analysis-Assumed Orbital Environment Using Well-Correlated Antenna Assembly Model Based on Thermal Balance Test

The deployable reflector antenna mounted on the SAR satellite is an antenna with a folding structure and is one of the main components of the satellite body. Due to the limited space inside the launch vehicle fairing, the mounting efficiency was improved by applying a structural feature that allows the antenna to be stowed compactly. In addition, weight reduction was required to lower launch costs and improve the satellite revisiting cycle; therefore, the main reflector of the deployable reflector antenna was designed and manufactured using carbon fiber reinforced polymer and aramid honeycomb core. Since the main reflector made of carbon fiber-reinforced polymer and aramid honeycomb core is not an isotropic material, differences between theoretical and actual thermal properties were expected. Therefore, in this study, a thermal balance test was performed on the thermal structure model of the deployable reflector antenna, and the thermal analysis model simulated by the ground test was corrected using the verified temperature conditions as a reference. The thermal properties of the composite material and the thermal conductivity coefficient between the main reflector and the main components connected to it were the targets of correction. In addition, a numerical optimization technique was applied to reduce computational costs, and the thermal analysis assumed the orbital environment model of the deployable reflector antenna was optimized using the corrected thermal properties.