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,

The scaled-down prototype, nicknamed the "Baby Boom", broke the sound barrier for the first time during a test flight over the Mojave Desert in California in late January. The small jet, officially called XB-1, reached an altitude of 35,000 feet before accelerating to Mach 1.1 (844mph) – "10% faster than the speed of sound", said Sky News.

When the experimental XB-1 aircraft achieved supersonic speeds on a test flight, it did not create a disruptive sonic boom – thanks to a physics phenomenon called the Mach cutoff

If you've been keeping tabs on aviation news as of late, you saw that Boom Supersonic just recently broke the sound barrier with its XB-1 demonstrator aircraft. Oddly enough, no one on the ground heard a thing during its "boomless" cruise.

Boom Supersonic’s XB-1 creates a sonic boom inaudible from the ground below when flying at the exact right speed and altitude.

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.

US aerospace firm Boom Supersonic is expecting to reach design freeze on the Overture supersonic passenger aircraft in about a week, as flight-testing of its experimental XB-1 jet concludes. The XB-1 departed on its 13th and final flight on 10 February,

GREENSBORO, N.C. — Boom Supersonic’s XB-1 is gearing up for another flight. The flight is set to take place around 1:30 p.m. on Feb. 10. It will be the 13th and final flight for the aircraft.