A heat rejection system includes a plurality of panel subassemblies and a solid state heat pipe flex joint. Each panel subassembly includes a fin, a solid state heat pipe manifold, a first solid state heat pipe tube operatively connected to the solid state heat pipe manifold and secured to the fin, a second solid state heat pipe tube operatively connected to the solid state heat pipe manifold adjacent to the first solid state heat pipe and secured to the fin. The solid state heat pipe flex joint operably connects the solid state heat pipe manifolds of two of the plurality of panel subassemblies in a hermetically sealed configuration, and is configured to permit repositioning of the two panel subassemblies relative to each other.