During the XB-1's historic flight on Tuesday—its 12th test flight overall—the aircraft stayed supersonic for around four minutes before breaking the sound barrier two more times during the same outing ...

Humankind was once determined to break the sound barrier, as it was considered the ultimate achievement in speed. But our technology didn't stop there, as we've built experimental vehicles that can ...

MILAN — Extreme athlete Felix Baumgartner, the first skydiver to fall faster than the speed of sound during a 24-mile leap through the stratosphere more than a decade ago, was killed in a crash ...