Thermal Design to Meet Stringent Temperature Gradient/Stability Requirements of Space Camera's Tube

摘要

A space camera is mounted on a remote sensing satellite in a low-earth orbit. The thermal environment of the space camera's tube is analyzed and the formula of external heat fluxes for tube is given subsequently. The factors affecting the temperature stability and gradient of tube are obtained. The tube is cold biased, and active thermal control system is used to meet requirements. System design based on multi-level insulation and graded heating is proposed. Passive thermal control strategies, such as enhanced thermal insulation design and optimum design of the baffle length, are used to reduce the sensitivity of space camera's tube to the external thermal environment. An active thermal control system is taken to solve the temperature control problem for multi-zone coupling with each other. In-orbit analysis of the last 3 years shows that, the temperature of tube is in the range of 20 °C ± 1.5 °C. The axial and circumferential temperature differences are less than 1 °C. The temperature fluctuation is less than 0.33 °C/3 month. Periodic average heating power for tube is 16.7 W. The validity of thermal design for tube is proved.