Thermal Design Analysis of Low Earth Orbit Optical Telescope ROKITS

The space thermal environment poses significant challenges due to its vacuum conditions, low pressure, and extreme temperature fluctuations. In Low Earth Orbit (LEO) spacecraft, the duration of the eclipse during each orbit complicates the maintenance of specific target temperature ranges. The Republic of Korea Imaging Test System (ROKITS) is an LEO space telescope equipped with an optical lens system. The optical performance of space optical telescopes such as ROKITS can be degraded by optical aberrations resulting from temperature discrepancies in the lenses and mirrors themselves. To minimize aberrations arising from temperature variations, thermal control hardware such as radiators and heaters must be precisely designed to maintain temperature requirements in the on-orbit space environment. Therefore, a comprehensive thermal control design based on thermal analysis results is necessary for all LEO space optical telescopes. We investigate the thermal control design of the radiator and heater for ROKITS. Both parametric and trade-off studies were conducted to determine the proper configuration for the radiator and heater, based on thermal analyses under the worst hot and cold scenarios. The results provide a feasible thermal control design for implementation.