An appropriate selection of control philosophy concepts not only from the system stability point of view but also according to system safety and reliability features is of the most importance in general design of thermal control loops.
Interconnection of several loops, presence of many heat sinks (namely space radiators), different heat load profiles due to various mission configuration, spacecraft orientation to sun, need complex control in order to make possible the functioning, even in the extreme working conditions.
In the present paper the author, on the basis of the past experience, investigates a wide range of radiator thermal control systems.
Free flyers heat rejection systems and their respective control units are investigated in order to focalize their most important features, from the heat rejection capabilities and temperature control point of view.
A parallel evaluation of the proposed solutions concludes this introductory study and shows some selection criteria among the alternative schemes.