SSM - N - 8 Regulus The SSM - N - 8A Regulus was a ship - and submarine - launched , nuclear - armed turbojet - powered cruise missile deployed by the United States Navy from 1955 to 1964 . Its barrel - shaped fuselage resembled that of numerous fighter aircraft designs of the era , but without a cockpit . When the missile was ready for launch , it was fitted with two large booster rockets on the aft end of the fuselage . History . Design and development . In October 1943 , Chance Vought Aircraft Company signed a study contract for a range missile to carry a warhead . The project stalled for four years , however , until May 1947 , when the United States Army Air Forces awarded Martin Aircraft Company a contract for a turbojet powered subsonic missile , the Matador . The Navy saw Matador as a threat to its role in guided missiles and , within days , started a Navy development program for a missile that could be launched from a submarine and use the same J33 engine as the Matador . In August 1947 , the specifications for the project , now named " Regulus , " were issued : Carry a warhead , to a range of , at Mach 0 . 85 , with a circular error probable ( CEP ) of 0 . 5 % of the range . At its extreme range the missile had to hit within of its target 50 % of the time . The design was long , in wingspan , in diameter , and would weigh between After launch , it would be guided toward its target by two control stations , usually submarines with guidance equipment . ( Later , with the " Trounce " system , one submarine could guide it ) . Army - Navy competition complicated both the Matador ' s and the Regulus ' developments . The missiles looked alike and used the same engine . They had nearly identical performances , schedules , and costs . Under pressure to reduce defense spending , the United States Department of Defense ordered the Navy to determine if Matador could be adapted for their use . The Navy concluded that the Navy ' s Regulus could perform the Navy mission better . Regulus had some advantages over Matador . It required only two guidance stations while Matador required three . It could also be launched quicker , as Matador ' s boosters had to be fitted while the missile was on the launcher while Regulus was stowed with its boosters attached . Finally , Chance Vought built a recoverable version of the missile , so that even though a Regulus test vehicle was more expensive to build , Regulus was cheaper to use over a series of tests . The Navy program continued , and the first Regulus flew in March 1951 . Due to its size and regulations concerning oversize loads on highways , Chance Vought collaborated with a firm that specialized in trucking oversize loads to develop a special tractor trailer combination which could move a Regulus I missile . Regulus II . A second generation supersonic Vought SSM - N - 9 Regulus II cruise missile with a range of and a speed of Mach 2 was developed and successfully tested , but the program was canceled in favor of the UGM - 27 Polaris nuclear ballistic missile . The Regulus II missile was a completely new design with improved guidance and double the range , and was intended to replace the Regulus I missile . Regulus II - equipped subs and ships would have been fitted with the Ships Inertial Navigation System ( SINS ) , allowing the missiles to be aligned accurately before take - off . Forty - eight test - flights of Regulus II prototypes were carried out , 30 of which were successful , 14 partially successful and only four failures . A production contract was signed in January 1958 and the only submarine launch was carried out from the USS " Grayback " in September 1958 . Due to the high cost of the Regulus II ( approx one million dollars each ) , budgetary pressure , and the emergence of the UGM - 27 Polaris SLBM ( submarine - launched ballistic missile ) , the Regulus II program was canceled on 18 December 1958 . At the time of cancellation Vought had completed twenty Regulus II missiles with 27 more on the production line . Production of Regulus I missiles continued until January 1959 with delivery of the 514th missile , and it was withdrawn from service in August 1964 . Ships fitted with Regulus . The first launch from a submarine occurred in July 1953 from the deck of USS " Tunny " , a World War II fleet boat modified to carry Regulus . " Tunny " and her sister boat USS " Barbero " were the United States ' s first nuclear deterrent patrol submarines . They were joined in 1958 by two purpose - built Regulus submarines , USS " Grayback " , USS " Growler " , and , later , by the nuclear - powered USS " Halibut " . So that no target would be left uncovered , four Regulus missiles had to be at sea at any given time . Thus , " Barbero " and " Tunny " , each of which carried two Regulus missiles , patrolled simultaneously . " Growler " and " Grayback " , with four missiles , or " Halibut " , with five , could patrol alone . These five submarines made 40 Regulus strategic deterrent patrols between October 1959 and July 1964 , when they were relieved by the carrying the Polaris missile system . " Barbero " also earned the distinction of launching the only delivery of missile mail . Regulus was deployed by the US Navy in 1955 in the Pacific on board the cruiser USS " Los Angeles " . In 1956 , three more followed : USS " Macon " , USS " Toledo " , and USS " Helena " . These four each carried three Regulus missiles on operational patrols in the Western Pacific . " Macon " ’ s last Regulus patrol was in 1958 , " Toledo " ’ s in 1959 , " Helena " ’ s in 1960 , and " Los Angeles " ’ s in 1961 . Ten aircraft carriers were configured to operate Regulus missiles ( though only six ever actually launched one ) . USS " Princeton " did not deploy with the missile but conducted the first launch of a Regulus from a warship . USS " Saratoga " also did not deploy but was involved in two demonstration launches . USS " Franklin D . Roosevelt " and USS " Lexington " each conducted one test launch . USS " Randolph " deployed to the Mediterranean carrying three Regulus missiles . USS " Hancock " deployed once to the Western Pacific with four missiles in 1955 . " Lexington " , " Hancock " , USS " Shangri - La " , and USS " Ticonderoga " were involved in the development of the Regulus Assault Mission ( RAM ) concept . RAM converted the Regulus cruise missiles into an unmanned aerial vehicle ( UAV ) : Regulus missiles would be launched from cruisers or submarines , and once in flight , guided to their targets by carrier - based pilots with remote control equipment . Replacement and legacy . Production of Regulus was phased out in January 1959 with delivery of the 514th missile , and it was removed from service in August 1964 . A number of the obsolete missiles were expended as targets at Eglin Air Force Base , Florida . Regulus not only provided the first nuclear strategic deterrence force for the United States Navy during the first years of the Cold War and especially during the Cuban Missile Crisis , preceding the Polaris missile s , Poseidon missile s , and Trident missile s that followed , but it also was the forerunner of the Tomahawk cruise missile . Surviving examples . The following museums in the United States have Regulus missiles on display as part of their collections :