Design and Hardware Implementation of Spaceborne Stargazing Camera System

A complete star-viewing camera was designed using a NOIP1SN025KA CMOS detector to improve the accuracy of attitude satellites. The anti-irradiation experiment was conducted using 60Co-γ radiation source under the environmental conditions of 24℃ irradiation temperature, 24℃ test temperature, and 37% RH test humidity. Subsequently, an optical system with a focal length of 500 mm, an F-number of 4, and a field of view of 2.4° are designed. The electronic system uses an FPGA as the core control device to control the CMOS output digital signal and transmits the signal back to the satellite data transmission system through TLK2711. The mechanical structure was mainly composed of a main mirror component, secondary mirror component, correction mirror component, baffle, and leg. The design scheme of the measuring cylinder (invar) supporting the secondary mirror was adopted to ensure that the interval change of the primary and secondary mirrors satisfied the tolerance requirements under the condition of temperature change. The mirror assembly was designed with radial and axial flexibility to ensure accuracy of the shape of the optical surface in the thermal environment. In the correction mirror assembly using pressure ring tangential pressing lens installation, the lens stress is small, good to neutral, impact, and vibration resistance, and can maintain good structural stability. The machine is connected to a satellite through the main mirror backplane. A star camera has two working modes: imaging and transmission of the threshold and coordinate information of the star point. Field imaging experiments showed that the camera exhibited good imaging quality, portability, and reliability. Approximately ten stars can be captured in the field of view, approximately 10 stars can be captured, and nine stars can be observed, which can effectively assist the star sensor.