In the mid-1950s, the AFSWC's Development Directorate began work on atomic warhead installations in guided missile weapons and the development of warhead support equipment. In January 1955, Douglas Aircraft Company was awarded the development contract for the weapon that became known as the Genie. The Genie was an air-to-air, unguided nuclear-tipped rocket that was designed for arming in the air moments before it was fired. The nuclear warhead of the Genie was a W-25 with a yield of approximately two kilotons. It was the only nuclear rocket to actually be launched and detonated from an aircraft, which took place at 20,000 feet over the Nevada Test Site on 19 July 1957. The original Genie was referred to as the MB-1 and later redesignated the AIR-2A; the carrier aircraft included the F-89J Scorpion, F-101B Voodoo, and F-106A Delta Dart. Other aerodynamic missiles developed at the Development Directorate were the SM-62 Snark, SM-64 Navaho, CIM-10 Bomarc and MGM-1 Matador.