In the Tile Shop at NASA's Kennedy Space Center, Boeing Rigid Insulation-18, or BRI-18, tiles of different shapes await use on the three orbiters: Discovery, Atlantis and Endeavour. BRI-18 is the strongest material used for thermal insulation on the orbiters and, when coated to produce toughened unipiece fibrous insulation, provides a tile with extremely high-impact resistance. It is replacing tiles on areas of the vehicle where impact risk is high. These areas include the landing gear doors, the wing leading edge and the external tank doors. Photo credit: NASA/Jim Grossmann