Ball Aerospace & Technologies Corp. is currently under contract to design, build, and test a state-of-the-art lightweight beryllium mirror for cryogenic space applications. This Advanced Mirror System Demonstrator (AMSD) has been designed for lightweight, deployable, spaceborne mirror applications. The major components are currently being fabricated and will comprise a lightweighted mirror assembly including a composite reaction structure. The 1.4-m point-to-point hexagon, semi-rigid beryllium mirror will be integrated with the reaction structure, actuators, and flexures to achieve a mirror system capable of ambient and cryogenic (20 to 55K) operation. The mirror prescription is an off-axis asphere of a parent with a 10-m radius of curvature. Presented here is the current status and a summary of the planned optical fabrication and testing. This work is being performed under a contract to Marshall Space Flight Center (MSFC) in Huntsville, AL and is co-sponsored by the USAF and the NRO.