An Alternative to Deployed Thermal Radiators: Deployed Equipment Modules with Individual Package Temperature Control

As small satellites' power-to-external area ratios increase, so does the ordeal of securing the necessary thermal radiator area. To provide robust temperature control for any conceivable power density, two new concepts are proposed: a satellite architecture based on deployed equipment modules for increased radiator area, and thermal switches on each package mounted to module panels. A beneficial synergy comes from employing these independent concepts on small satellites whose exterior panels serve as both equipment mounting decks and thermal radiators. Hypothetical examples of multiple module deployments demonstrate the potential for dramatic increases in effective radiator area that allows a comfortably large hot-case margin. Cold-case temperature control comes from thermal switches that vary package-to-deck interface pressure as a function of package temperature to provide high interface resistance at low temperature. Two such switches based on the temperature dependent properties of shape memory alloy and paraffin are described. Positive and negative comparisons are made to conventional thermal design and deployed radiators. The efficient and effective temperature control subsystem described reduces the need for: auxiliary heaters to maintain minimum temperatures, rigorous thermal design and analysis, design verification testing, sophisticated thermo-optical surfaces, and active temperature control (in the conventional sense) for the entire satellite. This has been a feasibility of concept study with no development hardware or testing. Opinions on usefulness, future direction, and potential application are solicited.