Satellite systems and operations in space are commonly complex and are mostly sensitive to orbital positioning and stability. The satellite propulsion system is one of the most important subsystems in the satellite. They are an essential subsystem for attaining the designed mission aims of the satellite. It works to keep the satellite on at the same altitude during the life mission and maintain an orbit through the generation of thrust force. The satellite subsystem is exposed to solar radiation (heat flux) and heat generated from the satellite components in the space environment. Therefore, in the current investigation, mainly the propulsion tanks of the satellite propulsion system will be the focal point and will be examined to ensure they can endure extreme space environment circumstances. FEMAP software creates a thermal analysis of a 3D thermal model using the KACST low-earth-orbit (LEO) mission. The predicted temperatures of the propulsion tanks are shown under extreme (cold and hot) and nominal conditions. A full solar day is used to capture the significant fluctuations in temperature variations. Results show that the minimum and maximum average predicted temperatures experienced by the propulsion tanks during the orbital operation are 8.39 and 26.65 °C, with a predicted nominal range of 14.55 and 17.36 °C, correspondingly. Lastly, the nominal predicted temperatures are compared with real values during orbital operations (KACST ground station), with ranging temperatures of 14.06 and 24.26 °C. The real and predicted temperatures fall within the accepted tolerance range of 0 to 40 °C.