The Pro/Ref-HUD technology will provide new capabilities for astronauts during EVA with a see-through display system that allows the astronauts to monitor the conditions around them while being provided visual instructions and direction in a hands-free format. This technology will allow astronauts to be more productive and take on less risk, and eventually translate to boresighted overlays for augmented-reality-based information. Applications include space walks on the International Space Station (ISS) where navigating the structure can be completed with maps and repairs completed with heads-up manuals. Harsh-environment training can also be completed with the HUD by providing assistance and navigation for improved safety such as dealing with Martian dust storms and facilitating asteroid landings. See-through HMD technology advances made possible by the successful development of the proposed Pro/Ref-HUD system will lead to cost-effective commercialization. In particular, this new HMD system will find numerous real time 3D virtual-reality and augmented-reality applications. The military has significant and various needs for HMD technology, including Distributed Mission Training, pilot and combat vehicle crew HMDs, thermal sights, Soldier's Integrated Protective Ensemble (SIPE), and logistics and training. In addition, we anticipate widespread appeal of the Pro/Ref-HUD technology to such entertainment industry applications as gaming HUDs, gaming flight simulators, and other immersive and augmented display systems, including medical and CAD/CAE 3D image displays, virtual-reality displays for endoscopy/laparoscopy, and displays for environmentally hazardous professions such as bomb disposal and hazmat clean up. Medicine, avionics, education, law enforcement, firefighting, space exploration, and video games represent major markets for compact, low-cost, lightweight HMDs in the private sector.