Strategic deterrence has been the sole mission of the fleet ballistic missile submarine (SSBN) since its inception in 1960. The SSBN provides the nation's most survivable and enduring nuclear strike capability. The Ohio class submarine replaced aging fleet ballistic missile submarines built in the 1960s and is far more capable.
Naval Submarine Base Kings Bay hosted the commissioning of USS LOUISIANA (SSBN 743) 06 September 1997 at the TRIDENT Refit Facility Drydock. The commissioning of LOUISIANA completed the Navy's fleet of 18 fleet ballistic missile submarines. The ten Trident submarines in the Atlantic fleet were initially equipped with the D-5 Trident II missile. The eight submarines in the Pacific were initially equipped with the C-4 Trident I missile. In 1996 the Navy started to backfit the eight submarines in the Pacific to carry the D-5 missile.