Proteus is the generic name of the Alcatel multi-mission platform for LEO small satellites (class 500 Kg). The development of this platform, currently in its final validation phase, is carried out in partnership between Alcatel and CNES. One of the ambitious objectives of this program is to make a design compliant with a very large range of flight without any other modifications than minor ones. Thus, the challenge for the Proteus thermal control subsystem is to develop a concept in accordance with this objective in a « faster, better, cheaper philosophy » context. This leads to a thermal control concept mainly driven by flexibility and adaptability requirements.