The MetOp-SG (Meteorological Operational Satellite - Second Generation) program includes a series of meteorological satellites developed by ESA in collaboration with EUMETSAT. MetOp-SG is designed to provide crucial data for weather forecasting, climate monitoring, and atmospheric research. These satellites are equipped with a range of advanced instruments that collect data related to atmospheric temperature, humidity, wind, cloud cover, and various other parameters, to help better understanding weather patterns, to track severe weather events, and to improve long-term climate predictions. MetOp-SG satellites will be built in two series: A, carrying visible, infrared, and microwave imagers and sounders; and B, carrying microwave imagers and radars. Each series includes three identical satellites. The first A-series satellite is foreseen to be launched in early 2025, while the first B-series satellite will be launched in late 2025. MetOp-SG satellites will fly on a Sun-synchronous orbit at 831km altitude. The common platform thermal control is managed by cavities, which include various subsystems and units. They feature a set of radiators, heaters and multi-layer insulation. The MetOp-SG A instruments have a more complex thermal control to satisfy some stringent low temperature requirements. Two instruments (IASI-NG and METimage) are equipped with cryostats actively cooled by cryocoolers, whereas the other instruments (Sentinel-5, 3MI and MWS) use passive cooling, which requires for two of them multi-stage radiators and various types of heat-pipes. The verification of this complex first spacecraft of the series has started with the thermal balance test of a Structural and Thermal Model to validate the platform thermal design. In 2023, the Proto-Flight Model of MetOp-SG A was tested in an exhaustive Thermal Balance and Thermal Vacuum test. This test required a complex thermal set-up, to satisfy all instrument needs and constraints, and also allowed a full verification of the thermal control.
Peyrou-Lauga et al. (Sun,) studied this question.