Abstract: A device for dissipating heat, for a space-based satellite, includes at least one dissipating panel, the dissipating panel having at least one skin formed from a composite structure comprising an organic resin and carbon fibers, wherein the organic resin is filled with carbon nanotubes. The heat-dissipating device may also comprise a network of heat pipes. The heat pipes may be made from an aluminum alloy incorporating elements having low coefficients of thermal expansion. The present invention is notably applicable to fixed dissipating panels or those that may be used in telecommunications, observation or scientific satellites, or else on racks assembled to dissipating panels.