New NASA X-Plane Could Bring Supersonic Flight to the Masses

If there’s a pantheon of great airplanes, the X-planes deserve an entire wing of the place. Since the Chuck Yeager-toting Bell X-1 broke the sound barrier in 1947, these experimental aircraft have pushed up against, and burst through, the boundaries of flight. The X-15 was the first plane to demonstrate hypersonic flight—over Mach 5—and set …