AKA: SAM-A-19. Status: Cancelled 1958.
In May 1946 the War Department Equipment Board first recognized the need for an anti-missile defense system. In 1951 studies were actively begun by the US Army to develop a system to defend against short- and medium-range ballistic missiles. Competitive design studies were carried out by Sylvania Electric and Cornell in 1953 – 1956. Sylvania was awarded a development contract in September 1956. The program was cancelled for lack of funds, rather than any technical deficiencies, by the Army Chief of Ordnance on 6 February 1959. The Army first considered an upgraded Hawk missile as a replacement for Plato; then decided to start all over again with a clean-sheet-of-paper ‘Field Army Ballistic Missile Defense System'. This in turn was canceled in 1962. Later upgrades to Nike Hercules and Hawk missiles provided the Army with a limited capability against short-range missiles. The Army remained with no defense against Soviet intermediate range missiles until these were scrapped by treaty in 1988.
Details of Project Plato remain mysteriously classified to this day. UFO enthusiasts believe it was a cover for an agreement with aliens that took effect in 1960.
Development Cost $: 18.500 million in 1955 dollars.