Developed as a supersonic cruise missile capable of flying faster than the speed of sound, the “Regulus II” could carry either a conventional or a nuclear warhead. Due to the development of the Polaris ballistic missile, the “Regulus II” program only lasted two years, with the program cancelled in December 1958. This particular missile, GM-2048, is the last “Regulus II” missile to fly and the only surviving example modified with landing gear for use as a supersonic target drone.