On the ground below, it has been written, a small group of researchers from the National Advisory Committee for Aeronautics (NACA)—NASA's predecessor organization—were the first to hear the thunder crack coming from the Bell X-1 rocket plane flying faster than the speed of sound.Now, aeronautical innovators with NASA's Quesst mission are poised to break the sound barrier again, only this time in a very different way that could make it possible for all of us to one day travel by air just as fast as any of the X-1 pilots who flew supersonic.And when that happens it will mark another historic milestone in flight, potentially opening a new era in air travel, where airline passengers might hop on a supersonic jet at breakfast time in Los Angeles to make a lunchtime reservation in New York City.With the X-59 and its quiet supersonic technology building on all that has been learned since the X-1 first proved it was possible to go beyond Mach 1, NASA hopes to enable industry to make faster-than-sound flight available to everyone."We've kind of been stuck with our airliners at about Mach .8 for the past almost 50 years, so being able to get there—wherever there is—much faster is still kind of an unfulfilled dream," said Peter Coen, NASA's mission integration manager for Quesst."