About 35,000 feet (10,670 meters) over the Mojave Desert, northwest of Los Angeles, Boom Supersonic's XB-1 became the first privately funded airplane to break the sound barrier during a test flight on Tuesday.

Boom Supersonic passed a major milestone Tuesday on its path to reintroduce supersonic commercial flights. After years of testing and refinement, a pilot flying the aerospace company’s XB-1 scale prototype finally broke the sound barrier during a livestream event—not once, not twice, but three times.

The Colorado-based company is aiming to build a Concorde-like supersonic aircraft—but has hurdles to clear before realizing that goal.