2-839-741 - Heritage Art/Heritage Images

This is the backup primary mirror for the Hubble Space Telescope manufactured by the Eastman Kodak Company. The blank for this mirror was fabricated by the Corning Glass Works using their high silicon Ultra Low Expansion Glass (ULE 7971). It consists of two 1-inch glass disks fused to the faces of a thin square eggcrate-like support structure. This support structure creates a mirror that weighs about one-fifth that of a solid piece of the same size but retains required rigidity and stability characteristics.