Langley Research Center can claim many historic firsts, some of which have proven to be revolutionary scientific breakthroughs. These accomplishments include the development of the concept of research aircraft leading to supersonic flight, the world’s first transonic wind tunnels, training the first crews of astronauts, the Lunar Landing Facility providing the simulation of lunar gravity, and the Viking program for Mars exploration. The center also developed standards for the grooving of aircraft runways based on a previous British design used at Washington National Airport. Grooved runways reduce aquaplaning which permits better grip by aircraft tires in heavy rain. This grooving is now the international standard for all runways around the world.