Preliminary thermal design of CubeSat

Abstract

This thesis will carry out the first thermal analysis of the NAOS CubeSat. The objective of this study is to verify that the temperatures of satellite components remain in their respective allowed ranges.

After a brief description of the satellite mission and configuration, its modeling will begin. First the complex shape of the satellite will be simplified in the Esatan geometric model. This model will be used by Esatan to define the thermal nodes and compute the radiative exchanges between the components. The modeling will continue with the definition of the thermal properties of the materials and surface finishes. The model will be corrected with the definition of capacitances and finished with the definition of conductive links between the shells.

After the definition of the worst cases, the first results will be obtained. It will be observed that the initial design will lead to excessive temperatures (for example 101.8 °C for the batteries). The design will have to be optimized. These optimizations will include the modification of the initial external surface finish replaced by white paint. The internal conductances will be improved by using five layers of copper inside the PCB and using a filler material for the spacers. Finally a realistic model of the detector assembly will be built. Its improvement will include the modification of the insulation and the increase of the radiator area.

With the final design determined, the worst cases, as well as intermediate cases, will be ran. The predicted temperatures of these cases will show that the batteries, ADCS and the detector will still present issues. Several recommendations for these components will then be suggested for future thermal designs of the satellite.