The Nike series missiles were surface-to-air missiles for point defense against aircraft and ballistic missiles. Development of the Nike-Ajax (SAM-A-7) began in 1945 at Bell Laboratories. The first Nike-Ajax site became operational in December 1953 and initial plans called for installations at forty major cities in the continental United States, as well as at U.S. installations in foreign countries. As deployed the Nike-Ajax consisted of a Douglas-built airframe and a Bell (Aerojet-General) powerplant guide by a Westinghouse radar guidance system. It was superseded by the more powerful Nike-Hercules (SAM-A-25) and Nike-Zeus and was phased out of the U.S. inventory by 1965.