NASA needs a cryogenic refrigerator for the 15-25K range for receiving arrays of ground-based antennas that will serve the telecommunications needs of future space exploration. We propose to develop a 15-25K Static-Helium Regenerator/Double Pulse Tube Cooler for receiving arrays. Our SHR/DPTC combines two of our technologies that have potential to enable pulse-tube coolers to operate efficiently in the 15-25K range: (1) our Static-Helium Regenerator (SHR) technology, which uses static helium for the regenerator's thermal mass; and (2) our Double Pulse Tube Cooler (DPTC) technology, which uses a recuperator (instead of regenerators) to transfer heat between two pulse-tube sub-cycles that operate in parallel and out-of-phase. In Phase I, we will perform system trades and generate a preliminary design of a 15-25K SHR/DPTC that minimizes life-cycle costs for receiving arrays. In Phase II, we will: develop and test SHR/DPTC components; integrate the SHR/DPTC components with cooler components we have already developed; and test the integrated cooler. In Phase III, we will build and sell SHR/DPTCs to the government and private sector.