Design and development Background Nazi Germany's use of the
V-1 flying bomb during
World War II marked the first combat deployment of a
cruise missile, highlighting the potential of a new class of weapon. Even before
Germany's surrender, the United States captured,
reverse-engineered, and
mass-produced its own version of the V-1, the
Republic-Ford JB-2 Loon, intended for use against
Japan. With the war's end and the onset of the
Cold War, the U.S. sought new ways to deploy
nuclear warheads. One proposal, put forward by Captain
Thomas Klakring, was to launch nuclear missiles from submarines. He argued that submarines would be far more difficult to detect and attack than surface ships, such as
aircraft carriers, while also introducing a new method of warhead delivery beyond
aircraft. At the time,
bombers were the U.S. military's only means of delivering nuclear warheads, a reliance that threatened to diminish the Navy's role and overemphasize a single approach to nuclear strategy. Klakring proposed launching the Loon from submarines to test his concept. Work began in 1946, and by 1947,
USS Cusk became the first U.S. submarine to fire a guided missile. Testing continued for several years, but significant issues arose.
Cusk nearly sank when a Loon exploded on deck, and the missile itself was slow, had limited range and payload, and was impractical for military use. Despite these shortcomings, the tests successfully demonstrated how a submarine could surface, launch a missile, and submerge again, making it difficult for an enemy to retaliate. The Navy acknowledged the concept’s potential but recognized the need for a missile specifically designed for submarine deployment.
Design The contract required the missile to have a range of at Mach 0.85, a warhead, and a
circular error probable (margin of error) of . 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, designated
KDU-1 and also used as a target drone, 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.
Ships and submarines deployed with Regulus I The first launch from a submarine occurred in July 1953 from the deck of , a
World War II fleet boat modified to carry Regulus.
Tunny and her sister boat were the United States's first nuclear
deterrent patrol submarines. They were joined in 1958 by two purpose-built Regulus submarines, and , and, later, by the nuclear-powered .
Halibut, with its extremely large internal hangar could carry five missiles and was intended to be the prototype of a whole new class of cruise missile firing SSG-N submarines. The Navy strategy called for four Regulus missiles 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 each, or
Halibut, with five, could patrol alone. Operating from
Pearl Harbor, Hawaii, the five Regulus submarines made 40 nuclear deterrent patrols in the Northern Pacific Ocean between October 1959 and July 1964, including during the
Cuban Missile Crisis of 1962. According to the documentary "Regulus: The First Nuclear Missile Submarines" by
Nick T. Spark, their primary task in the event of a nuclear exchange would be to eliminate the Soviet naval base at
Petropavlovsk-Kamchatsky. These deterrent patrols represented the first by the Navy's submarines and preceded those made by the
Polaris missile submarines.
Barbero also earned the distinction of launching the only delivery of
missile mail. Additional submarines including USS
Cusk and USS
Carbonero were equipped with control systems that allowed them to take control of a Regulus in flight, thus extending its range in a tactical situation. Production of Regulus was phased out in January 1959 with delivery of the 514th missile; in 1962, it was redesignated RGM-6. It was removed from service in August 1964. Some 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 missiles,
Poseidon missiles, and
Trident missiles that followed, but it was also the forerunner of the
Tomahawk cruise missile.Following retirement, a number of Regulus I missiles were converted for
target drone usage under the designation BQM-6C. ==Regulus II==