Abstract
Remote sensing satellites are like space mirrors that help map land use, monitor disasters, and track environmental changes. They provide valuable data for various applications, from urban planning to climate research. The problem is that space temperatures vary drastically, ranging from 120°C in direct sunlight due to the Sun's intense radiation. This condition is called worst-case hot temperature —since there is no atmosphere to block or moderate it—to as low as -180°C when in Earth's shadow, and this is called worst-case cold temperature. Satellites are equipped with electronic systems that must function within specified temperature limits (from -10°C to 50°C) over their operational lifespans, making it essential to manage thermal conditions to maintain these limits. To address this issue, we used a thermal control system (both passive and active), which will be discussed further in this paper. However, there is a research and knowledge gap in the literature addressing the design and control of remote-sensing satellites in low Earth orbit. This investigation aims to fill this knowledge gap by developing a comprehensive thermal analysis and thermal control model for the "Space Sight MED 2025" remote sensing satellite in low Earth orbit. The developed computational thermal analysis clearly defines the satellite subsystems' worst-case hot and cold temperatures. Two extreme scenarios of extreme hot and extreme cold sun fluxes were considered in a passive system mode. The radiators' areas, temperatures, and locations on the satellite panels were analyzed under the hot scenario. At the same time, the power and operating conditions of the heaters were evaluated based on the cold scenario. Five heaters, each with an 8-watt power rating of 40 watts. Results showed that the 0.5871m² of radiator area is required. The temperatures of the electronic and electrical equipment should range from −7°C to+40°C. However, due to its high sensitivity to temperature changes, the battery should be kept in lower temperatures from 2°C to +28°C.