One startup is looking to shake things up. Boom Supersonic, founded in 2014 in Denver, Colorado, aims to bring back commercial supersonic flight by the end of the decade. Their CEO, Blake Scholl, says they are “four to five years away from carrying passengers”. In January, Boom’s prototype XB-1 achieved its first successful flight at the Mojave Air & Space Port in California, reaching 35,290 feet before accelerating to a top speed of 750 mph and breaking the sound barrier three times. “A good start to the year,” Scholl says.