In spacecraft design, the thermal control system (TCS) has the function to keep all the spacecraft parts within acceptable temperature ranges during all mission phases, withstanding the external environment, which can vary in a wide range as the spacecraft is exposed to deep space or to solar or planetary flux, and rejecting to space the internal heat dissipation of the spacecraft itself.The thermal control is essential to guarantee the optimum performance and success of the mission, because if a component encounters a temperature which is too high or too low, it could be damaged or its performance could be severely affected.