Boom hopes its breakthrough will allow supersonic flights over land, making US coast-to-coast flights 90 minutes faster.

During the second supersonic flight of the XB-1 technology demonstrator today, the jet exceeded Mach 1 three times without a boom being detected by microphones on the desert floor below.

Boom Supersonic passed a major milestone last month when its XB-1 prototype became the first civil aircraft to break the sound barrier over the continental US. Less than a month later, Chief Test Pilot Tristan “Geppetto” Brandenburg has once again surpassed Mach 1 in the experimental plane while flying as high as 36,