Abstract

Global Change Observation Mission-Climate (GCOM-C) “Shikisai” is a satellite observe global climate change. It was launched on December 23, 2017 by H2A launch vehicle from Tanegashima space center. The Second-generation GLobal Imager (SGLI) on GCOM-C is a multi-channel optical sensor to observe aerosols, vegetation and temperatures. Through long-term monitoring，understanding climate change mechanism will be improved. InfraRed Scanner (IRS) on SGLI has a Thermal InfraRed (TIR) detector. The detector is requested to operate at 55K. A Cooler Dewar Assembly (CDA) was developed to keep the detector at 55K. The CDA is designed to minimize heat load for the small cooler. The detector is supported on thermal isolator made of Glass FRP and thermally connected to the cooler by flexible thermal link. A Cooler Control Electronics (CCE) compensates fluctuation of heat load by using heater to maintain temperature and its stability. Heater power gradually decrease in 5 years. This means decrease of cooling power. Although degradation of the cooler，the detector is successfully kept in temperatures 55±0.1K for 5years in orbit and continue operating with 36W power consumption. This paper describes the cooler Dewar Assembly and its 5 years operation in orbit.