The Space Optics Manufacturing and Technology Center at NASA's Marshall Space Flight Center in Huntsville, Ala., has completed a master mold for the production of Fresnel lenses, using its unique diamond-turning equipment. The lenses will be employed in the production of screens for high-resolution monitors.At left, Wes Brown, the center's lead diamond turner, examines the uniformity of the 6000 grooves on the master. The master mold will be used to construct other molds, each of which will produce hundreds of Fresnel lenses.