The T-38 Talon is the world’s first supersonic trainer, first flown in 1959. Tens of thousands of pilots learned to fly in T-38s. The US Air Force is the primary user of the T-38, but Talons are also used by the US Navy and several NATO (North Atlantic Treaty Organization) member nations. NASA (National Aeronautics and Space Administration) also maintains a fleet of T-38s, flown by astronauts to maintain their flight proficiency and used as chase planes.