Headquartered in Buffalo, NY from 1935 to 1960, the Bell Aircraft Corporation was one of the foremost aircraft firms of the United States. Although a builder of several types of fighter aircraft during World War II, the corporation was most famous for the Bell X-1, the first supersonic aircraft, and for the development and production of many civilian and military helicopters. In addition, Bell also developed reaction controls for the Mercury Spacecraft, the North American X-15A, Minuteman and Centaur rockets. Some later research and development included VTOL/STOL technology, including the XV-3 convertiplane, X-22A, the rocket belt, and Lunar landing training vehicles (LLTV). It was 1960 that Textron Inc. purchased the defense activities of Bell Aircraft Corp properties including the helicopter operation. Textron organized a wholly-owned subsidiary Bell Aerospace Corp focusing on space related activities and the Bell Helicopter Company in Hurst, TX which continued to develop and produce rotary-wing aircraft.