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

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.

Boom Supersonic, the American company building what promises to be the world’s fastest airliner, broke the sound barrier for its first time with a test flight in Mojave, California, on Tuesday.