A small satellite preliminary thermal control and heat shield analysis

Abstract

As part of a student owned small satellite project, a preliminary thermal control and heat shield analysis was developed to verify acceptable performance requirements for the system. For the thermal control section, the analysis was focused on the Bus module of the satellite. It measured the effects of the Sun and Eclipse periods at low earth orbit (LEO), accounted key design and subsystems interaction considerations and indicated some of the structural parameters available for its success. As for the heat shield section, calculations were made to quantify the magnitude of the heat flux going into the payload capsule. The thermal control analysis was implemented to determine if the radiator area and insulation from the aluminum honeycomb structure were sufficient to maintain the electronic components at proper operating temperatures during the mission. Materials such as insulating coating paints and mechanisms such as heaters were researched and considered as additional thermal protection barriers. Thermal subsystems interfaces, i.e. Bus-Return Vehicle Interface, were also analyzed. Models for the incoming heat across the Ablator heat shield were used to determine values for transient and steady-state heating and cooling scenarios. These provided indications of the incoming and outgoing heat transfers into and out of the payload module. With the use of thermal resistance models, values for the heat transfers were obtained. This study interpreted the thermal effects of orbiting Earth at LEO for the Bus module of a small satellite. It also measured the effectiveness of the heat shield on preventing incoming heat transfers into the payload module. From proper approximations, realistic results were obtained for both cases. Though no in depth analysis was performed, actual values obtained for the heating effects provided a valid scope of the overall effects on the system.