Heat Flux-Based Calorimeter for Active Thermal Coatings

We propose to develop a calorimeter for accurately measuring the performance of active thermal control materials that can be easily deployed on spacecraft and satellites. Our calorimeter will be based on thin film heat flux gauges, which measure heat flux by determining the temperature difference across a thermally insulating film. The temperature on each side of the film is measured via an array of thin film conductors. These conductors can be accurately deposited in a complex pattern, so a large number of individual heat flux sensors can be incorporated in a small area. This technique provides a direct measure of the heat flowing through the surface, so the performances of the thermal control materials mounted on these sensors are obtained directly. The low thermal capacitance of these heat flux sensors will provide good temporal resolution of the heat flux. The small size of the sensors will allow the necessary spatial resolution to resolve the performance of several different coatings or active thermal control materials on one of our calorimeters. The ability to test multiple samples will allow the testing of multiple samples of the same device or the monitoring for spatial variations across a single thermal device.