The official land-speed record (measured over one mile) is 1,227.985 km/h (763.035 mi/h) (Mach 1.020), set by Andy Green (UK) on 15 October 1997 in the Black Rock Desert, Nevada, USA, in Thrust SSC. Although Thrust SSC is the first car to break the sound barrier, it is alleged that Budweiser Rocket Car, driven by Stan Barrett (US), reached a speed of 1,190.377 km/h (739.666 mi/h) at Edwards Air Force Base, California, USA, on 17 December 17 1979. However, the published speed of Mach 1.0106 was not officially sanctioned by the USAF, as the Digital Instrument Radar was not calibrated or certified. The radar information was not generated using the vehicle directly but by an operator aiming aiming a dish using a TV screen. The car is powered by two Rolls-Royce Spey 202 jet engines which generate 222 kN (50,000 lb) of thrust.