Thermal Control Design Methodology for Satellites with Spherical Battery Arrays Serving as the Outer Shell

The increasing prevalence of low-altitude activities has heightened the demand for precise atmospheric environmental data. Against this backdrop, the construction and operation of high-precision atmospheric density detection satellite constellations will become a crucial means for atmospheric environment observation. This paper presents the design of a spherical satellite optimized for detection performance under multiple constraints, including extremely low cost, constant windward orientation across various attitudes, and adaptability to diverse orbits. Addressing the challenge of implementing satellites based on a spherical solar array shell - which lacks traditional radiating surfaces and suffers from excessively high temperatures on the illuminated shell areas - it proposes using high-thermal-conductivity heat pipes to achieve temperature equalization across the spacecraft's spherical solar array. This maintains a small temperature gradient across the array itself. Concurrently, the thermal contact resistance between the internal primary structure and the heat-radiating regions of the spherical solar array is designed to ensure both the array and the internal equipment operate within suitable temperature ranges. The specific method involves: Utilizing the industrially mature spinning process to achieve integrated hemispherical forming; Installing low-cost, industrial-grade carbon-nanotube copper foil between the primary structure and the spherical shell to create flexible thermal conduction channels; evenly attaching high-thermal-conductivity heat pipes to the inner side of the spherical shell. These leverage their high thermal conductivity to transfer heat from the illuminated shell regions to heat-radiating areas, where it is then radiated to the deep space cold background by exploiting the high infrared emissivity of the solar cells. The paper analyzes on-orbit telemetry data from an atmospheric density detection test satellite employing this design. The results show all satellite equipment operating within a temperature range of 10 °C to 25 °C, meeting equipment temperature requirements. This demonstrates the method's rationality and effectiveness, providing a design basis for satellites utilizing spherical solar arrays as their outer shell.