US Navy Submarine launched Nuclear Ballistic Missile.
The two stage Polaris A1 missile was a solid fueled submarine launched, medium range ballistic missile. First launched from Cape Canaveral in 1960, it was a replacement to the Regulus Cruise missile. The A1 had a range of 1000 nautical miles, carrying a single Mk 1 RV with a W-47 nuclear warhead.