Cornerstone Research Group, Inc. (CRG), has developed sandwich core composite material (SynLam(TM)) and related fabrication technology to address the drawbacks of conventional materials and fabrication processes for space-based mirrors. The resulting technologies will directly address NASA's requirement for advanced, low-cost, high quality large optics fabrication processes for building imaging systems that support the Space Science Enterprise's Structure and Evolution of the Universe Theme. Extending recent CRG advancements in syntactic composites by tailoring the material system to cryogenic applications, the new material will achieve a balance of mass, structural, thermal, and optical properties that dramatically advances the state-of-the-art for space-based mirrors. The new material will also enable mirror fabrication techniques that are significantly faster and cheaper than current practice. Currently available syntactic materials show the potential of this class of composite for application in lightweight mirrors. Integrated development of the new material and new process technology will yield synergy in advancing the state-of-the-art in both areas.