In an interconnected world where technology progresses at an incessant pace, the aerospace sector is experiencing a consistent and rapid growth. The rising demand for satellites for everyday activities such as navigation and communication, as well as for application like science, earth observation, and defense, is driving the industry towards more efficient design, assembly, integration, and testing to meet these demands. In particular, the thermal control system is a crucial part of any satellite, heavily influenced by specific mission requirements. Effective design and optimization of this system ensure the creation of reliable and long-lasting products, benefiting the entire production chain. This thesis, in collaboration with the DONI department of Thales Alenia Space, aims to evaluate the maximum thermal power dissipation of a typical geostationary satellite using ESATAN-TMS® thermal analysis software.