It took off with a bang. Boom Supersonic’s XB-1 jet broke the sound barrier for the first time on Monday as the American company seeks to deliver the world’s faster airliner capable of carrying passengers between New York and London in just over 3 1/2 hours.

A prototype of a passenger jet designed to succeed the supersonic Concorde broke the sound barrier for the first time on Tuesday above the Mojave Desert in California. Why it matters: Exceeding Mach 1 speed — 770 miles per hour — is an important milestone in the quest by Boom Supersonic,