On October 14, 1947, a 24-year-old test pilot named Chuck Yeager climbed into a bullet-shaped orange plane called the Bell X-1 while it dangled from the belly of a much bigger plane high over California's Mojave Desert. Two days earlier, Yeager had broken two ribs falling off a horse, but he had hidden it from the Air Force so they wouldn't pull him off the flight. He couldn't reach the cockpit door handle, so a friend gave him a broom handle to use as a lever. Then the big plane dropped him.
Yeager fired the X-1's four rocket engines and shot forward across the sky. The plane shook violently as it neared the speed of sound - about 767 miles per hour at sea level, slower at high altitudes. Nobody knew if a plane could survive what pilots called 'the sound barrier.' Some experts thought the aircraft would shatter. Yeager pushed past it anyway. On the ground, observers heard a sudden BOOM - the first ever sonic boom from a human-piloted plane. He had reached Mach 1.06. The barrier was broken.
The achievement was kept secret for nearly a year, then announced to the world. It opened the door to supersonic flight, to jet fighters that could chase each other faster than sound, to the Concorde airliner that whisked passengers across the Atlantic in three hours, and to spacecraft that would one day rocket far beyond. The X-1 itself now hangs in the Smithsonian's National Air and Space Museum in Washington, D.C., still painted bright orange, still nicknamed 'Glamorous Glennis' after Yeager's wife.
