The California class was a pair of nuclear-powered guided-missile cruisers operated by the United States Navy between 1974 and 1998. Other than their nuclear power supply and lack of helicopter hangars, ships of the California class were comparable to other guided-missile cruisers of their era, such as the . The class was built as a follow-up to the nuclear-powered , , and classes. Like all of the nuclear cruisers, which could steam for years between refuelings, the California class was designed in part to provide high endurance escort for the navy's nuclear aircraft carriers, which were often limited in range due to their conventionally powered escorts continuously needing to be refueled. Overview was the fourth nuclear-powered cruiser in the US Navy; the previous three were , , and . The second California-class cruiser, , was the fifth nuclear-powered cruiser in the US Navy. Other than the four ships of the Soviet Navy's , which were built with a combination of nuclear and fossil-fuel propulsion, no other country has launched nuclear-powered cruisers. Only two ships of the class were built, California and South Carolina, and both were decommissioned in late 1999. These ships were followed on by the four nuclear-powered cruisers of the . These cruisers were named for states because they were seen as quite large, powerful, capable, and survivable ships. California and her sister ship, South Carolina, were equipped with two Mk 13 launchers, fore and aft, capable of firing the Standard SM-1MR or SM-2MR surface-to-air missiles, one Mk 112 launcher for ASROC missiles, and eight Mk 141 launch tubes for Harpoon missiles. They were equipped with two Mk 45 5-inch rapid-fire guns, fore and aft. Four 12.75-inch torpedo launchers (two on each side, protruding from their magazine space on the main deck) were fitted for lightweight anti-submarine torpedoes. Two Mk 15 Phalanx 20 mm close-in weapon systems were fitted in the 1980s. The ships were originally designed to carry and launch the Mark 48 torpedo from a large space beneath the flight deck aft. Although a surface-launched version of the Mk 48 was never produced, the ships retained this large magazine space until their retirement. Both ships underwent a mid-life refueling and overhaul in the early 1990s to give them a further 18 years of active service. This modernization upgraded their two 150 MW D2G reactor plants with new 165 MW D2W reactor cores, installed the New Threat