Abstract
A high fidelity thermal model was developed to insure that propulsion and payload thermal requirements are maintained during FalconSat-5's useful life and flight operations. The unique propulsion subsystem on-board the microsatellite causes relatively large heat dissipation during its operation, and it has been shown by preliminary thermal analysis to affect the strict thermal requirements of the satellite. Based on a simple 1-D thermal analysis performed by the propulsion subsystem vendor, individual propellant tank heaters were added to the propulsion subsystem design. These individual tank heaters were designed to operate for 10 minutes before thruster firing. Further inspection of the newly designed propulsion subsystem showed that the power consumption of the propellant tank heaters would require a large power source, which would ultimately dissipate a relatively large amount of heat during the propulsion subsystem's operations. The high fidelity thermal model created in this study was used to determine if thermal requirements would be maintained during flight operations of the FalconSat-5 microsatellite. Thermal Desktop® was used to create the thermal model and fidelity was gained by accurately accounting for real material properties, surface optical properties, component thermal masses and detailed heat loads. A parametric analysis was conducted, which included the heat dissipated as a result of the individual tank heater’s operation and the 10 minute Hall-effect thruster's operation. The parametric analysis was used to find any thermal issues and suggest revisions to flight operations to solve these issues. WISPERS, iMESA and the array of battery cells all remained within their thermal requirements during the analysis. From the high fidelity thermal model it was determined that operating the individual tank heaters for 10 minutes would cause the maximum temperature requirements of the propellants to be exceeded. This would cause the internal pressures to exceed the requirements of the valves, resulting in valve failure and mission loss. Correct operating times for each heater were found and suggested such that the revised flight operations would insure all thermal requirements were maintained during flight.