The only person to break the sound barrier in a car has earned another world record, this time in a show of force for hydrogen power. British driver Andy Green reached 406.320 mph in a car powered by two hydrogen internal combustion engines, setting the record for that vehicle category, according to the international governing body of motor sports. The 64-year-old retired Royal Air Force pilot rocketed across the crystalline crust at Utah’s famous Bonneville Salt Flats in a car engineered by British construction equipment manufacturer JCB. Tuesday’s feat didn’t come close to approaching his overall land-speed record of 763 mph, which he set in 1997 in a car powered by jet engines and which caused sonic booms.