WINNER: NASA Langley’s Fiber-optic Strain Sensor
INNOVATOR: Mark Froggatt
Engineers follow a simple rule for avoiding disasters: Build things stronger than they need to be. That works pretty well with bridges and dams, where a little extra concrete never hurts, but aerospace technologist Mark Froggatt knew it was not appropriate for the space shuttle, where every ounce counts. He also knew NASA wanted an alternative to its current practice of essentially ripping the shuttle apart after each flight to look for parts failing under the enormous stresses of spaceflight.
So Froggatt and his colleagues at NASA Langley Research Center in Hampton, Virginia, built an early-warning device that provides detailed information about even minuscule cracks and deformations, allowing engineers to get away with a narrower margin of safety when building airplanes and spaceships. It’s a five-thousandths-of-an-inch-thick fiber- optic cable, and along every foot of its length Froggatt writes a group of tiny lines--called a grating--with ultraviolet light. Then he glues the fiber to the side of a part, such as a fuel tank, and shines a laser beam down the fiber. From the reflected light, he can tell which gratings are under stress.
