Thermal balance testing for advanced, lightweight solar array designs

The traditional modular building block for space solar arrays consists of solar cells mounted to an aluminum honeycomb panel with carbon composite facesheets. This design not only provides the structural rigidity for the array, but is critical for heat dissipation during operation in the space. The honeycomb provides consistent thermal conduction and emissive properties throughout the panel, and good thermal conduction from the solar cell to the panel all combine to produce a well-proven highly reliable mechanism for radiative heat transfer to space that is relatively simple to model, and therefore provide uniform solar cell operating temperatures. New, lightweight solar array designs are currently under development that differ from these traditional honeycomb panels. These new designs offer significant improvements in array specific power (watts per kilogram) and stowed volume. However, due to the unique, lightweight design of the blanket structure (interconnected solar cell attachment and support interface), these advanced array designs offer a significant challenge with regard to heat dissipation and accurate thermal modeling of the solar array. Recent modifications to facilities at the NASA Glenn Research Center provide thermal balance testing of new solar array designs to determine cell operating temperatures under various space environments.