The Polaris missile was a submarine-launche, two-stage solid-fuel nuclear-armed ballistic missile (SLBM) built during the Cold War by Lockheed for the United States Navy. It was designed to be used as part of the US Navy's contribution to the United States' arsenal of nuclear weapons, replacing the Regulus cruise missile. Known as a Fleet Ballistic Missile (FBM), it first flew from Cape Canaveral on January 7, 1960.