Abstract: A solar receiver includes a cavity that is operable to receive concentrated solar energy and a heat exchanger in thermal-receiving communication with the cavity. The heat exchanger includes a plurality of thermal capacitors. Each of the plurality of thermal capacitors has a regular geometry. The plurality of thermal capacitors defines open flow passages there between and at least two of the plurality of thermal capacitors have a different size. The plurality of thermal capacitors has a packing factor of greater than 74% with regard to the volume of the heat exchanger.

Abstract: 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.

Abstract: A solar receiver includes a cavity that is operable to receive concentrated solar energy and a heat exchanger in thermal-receiving communication with the cavity. The heat exchanger includes a plurality of thermal capacitors. Each of the plurality of thermal capacitors has a regular geometry. The plurality of thermal capacitors defines open flow passages there between and at least two of the plurality of thermal capacitors have a different size. The plurality of thermal capacitors has a packing factor of greater than 74% with regard to the volume of the heat exchanger.

Abstract: A thermal insulator includes a plurality of insulation layers with a first insulation layer spaced apart from a second insulation layer such that there is an open gap there between. At least one of the first insulation layer or the second insulation layer includes a substrate and an infrared-reflective coating on the substrate.

Abstract: 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.

Abstract: A direct carbon fuel cell includes a vessel having a liquid anode region and a separation device connected with the liquid anode region for separating constituents from a liquid anode material circulating through the liquid anode region.