The Boeing 777X will fly at transonic speeds similar to other widebody aircraft, while the Boom Overture will fly supersonic.

NASA’s X-43A was a small, unmanned experimental aircraft that, in 2004, shattered world records by flying at nearly Mach 10 (almost 7,000 mph), becoming the fastest air-breathing vehicle in history.

Even as the B-1B Lancer is on track to be retired in the mid-2030s to make way for the Northrop Grumman B-21 Raider, the Air Force has continued to enhance its capabilities.