Space-Based Radar Thermal Control

An innovative lightweight concept achieving improved thermal control and near isothermal operation for Space-Based Radar antenna systems is proposed. A totally passive thermal control approach controls the wide temperature variations experienced duringorbit transit between daylight and eclipse periods and radar electronic power-on and off operation. The concept significantly improves operation of the temperature sensitive electronic components and reduces dimensional distortion of the antennaphased-array aperture. The thermal control concept utilizes a phase change material (PCM), which exploits its large latent heat capacity to effectively store thermal energy during the daylight/electronic power-on periods and extract heat during theeclipse/power-off periods to maintain the antenna structure temperature and protect the electronic components during the cold soak. The concept has several innovative features to enhance the thermal control of the antenna structure including: high thermalconductivity Gr/epoxy face sheets (for improved thermal spreading); high latent heat capacity phase change material (contained integrally within the antenna structure); and an ultra-low density/high thermal conductivity carbon foam core (for enhancedthermal transport between the PCM and antenna structure). The overall design concept provides a mass efficient and highly effective thermal control approach that requires no additional parasitic power demands.