The Lockheed F-94 Starfire was a first-generation jet aircraft of the United States Air Force. It was developed from the twin-seat Lockheed T-33 Shooting Star in the late 1940s as an all-weather, day/night interceptor. The aircraft reached operational service in May 1950 with Air Defense Command, replacing the piston-engined North American F-82 Twin Mustang in the all-weather interceptor role.