Utilization of polymeric smart materials for heterarchical thermal control of spacecrafts systems

A passive thermal switch was developed to enable heterarchical (decentralized) thermal control of spacecraft components. The switch utilizes an expansive polymer (paraffin) as the working medium. The thermal switch is a small mechanical stand‐off with a variable conductance ranging from 0.015 W/K to 0.45 W/C as the temperature of the component to which it is connected varies from 290 K to 298 K. This device enables accurate, non‐electronic thermal control of spacecraft components when used to connect the component‐to‐be‐controlled to a heat sink. Variations in heat load to the component are accommodated by the variable conductance of the switch. The use of the thermal switch as the basis for a heterarchical thermal control strategy is presented. The design and operation of the heat switch is discussed. Results from thermal vacuum testing are presented with a summary of test‐derived characteristics.