Original vintage 1965 Goodyear Aerospace advertisement for the company's nuclear warhead-capable UUM44 SUBROC ("Submarine Rocket") anti-submarine missile - of note, this advert was published in the U.S. Boy Scout magazine "Boy's Life," and makes zero disclosure it is a nuclear-armed missile, only noting that the, "SUBROC needn't make a direct hit to be effective.  Once in the enemy's proximity, it re-enters the water, submerges, and explodes the warhead. Shock waves alone could destroy hostile craft" - how very, very Cold War of Goodyear Aerospace.
 
The UUM-44 SUBROC was a type of submarine-launched rocket deployed by the United States Navy as an anti-submarine weapon, and carried a 25 kiloton tactical nuclear warhead configured as a nuclear depth bomb.  The SUBROC was the first and only submarine-launched long-range nuclear armed anti-submarine missile ever deployed by the U.S. Navy.
 
Dimensions: Approximately 9.75 inches wide by 13 inches high.
 
In the early 1950s, sonar technology had advanced to such a level that the detection range of submarines became larger than the range of contemporary torpedoes.  Various studies discussed nuclear-armed submarine-to-submarine missiles to give U.S. attack subs an engagement range matching its detection range.  
 
Finally, in June 1958, the Naval Ordnance Laboratory (NOL) White Oak began the development of a solid-rocket powered underwater-air-underwater missile.  The new missile was designated SUBROC MK 28 at the time.  Early in the program, Goodyear Aerospace – the publisher of the vintage advert here – was selected as prime contractor for system integration and production.
 
The SUBROC could be launched from a 21-inch submarine torpedo tube – after launch, the solid fuel rocket motor fired and SUBROC rose to the surface.  The attitude then changed and SUBROC flew to its destination following a predetermined ballistic trajectory.  At a predetermined time in the trajectory, the reentry vehicle (containing the warhead) separated from the solid fuel motor, and the low kiloton W55 nuclear depth bomb dropped into the water and sank rapidly to detonate near its target.  A direct hit was not necessary.
 
The W55 was 13 inches (33 cm) in diameter, 39.4 inches (100 cm) long, and weighed 465 lb (211 kg).  Some sources suggest the W55 evolved from the experimental bomb tested in the Hardtack I Olive nuclear test on July 22, 1958, which had a full two-stage yield estimated at 202 kilotons.
 
SUBROC's tactical use was as an urgent-attack long-range weapon for time-urgent submarine targets that could not be attacked with any other weapon without betraying the position of the launching submarine by calling for an air-strike, or where the target was too distant to be attacked quickly with a torpedo launched from the submarine.
 
An added advantage was that SUBROC's approach to the target was not detectable by the target in time to take evasive action, although the warhead yield would appear to make evasive maneuvers unrealistic.  However, SUBROC was less flexible in its use than similar non-nuclear weapons – since its only payload was a nuclear warhead, it could not be used to provide stand-off fire in a conventional (i.e., non-nuclear) engagement.
 
SUBROC was one of several weapons recommended for implementation by Project Nobska, a 1956 study on submarine warfare.  Development began in 1958, with the technical evaluation being completed in 1963.  SUBROC reached Initial Operation Capability (IOC) aboard the attack submarine Permit in 1964; when the missile reached the IOC milestone, the US Navy's admiral in charge of weapons procurement stated that SUBROC was "…a more difficult technical problem than Polaris."
 
The first test launch of a SUBROC prototype occurred in August 1959, but numerous technical problems delayed the program.  The SUBROC was launched from torpedo tubes, which had to be filled with water before launch, and the cold sea water chilled the solid fuel, which lead to inefficient missile propulsion.  The creation of air bubbles during the initial underwater passage of the missile could prevent motor ignition or interfere with the guidance system.
 
Finally, all missile systems, including the inertial system and the nuclear warhead, had to withstand the extreme mechanical forces on the missile during water exit and reentry.  These problems where not solved until 1965, when the UUM-44A SUBROC (so designated in June 1963) became operational on the USS Permit (SSN-594).  Apart from the Permit class, SSNs of the Sturgeon (SSN-637) and Los Angeles (SSN-688) classes were also equipped with SUBROC .  The typical SSN load of SUBROCs was four to six UUM-44A missiles.
 
SUBROC production ended in 1968, and the nuclear-based anti-sub missile was never used in combat;  all 285 W55 warheads were decommissioned in 1990 following the end of the Cold War.  Because the nuclear warhead was an integral part of the weapon, SUBROC could not be exported to other navies, and there is no evidence that any were supplied to other NATO allies under the well-established arrangements for supplying other dual-key nuclear weapons.