Titan ballistic missile

Along with the Minuteman II and Minuteman III, the Titan II constituted from the mid 1960s to the mid 1980s the only force of ICBM deployed in the western world. The strong increment - not only in number but in precision and destructive power as well - of the Soviet missiles, led in the mid 1970s to start a new program, the MX, whose realization would take a decade.

In 1953, in the very beginning of the American initiatives to develop an intercontinental ballistic missile (ICBM), the Strategic Missiles Evaluation Committee (SMEC) recommended that, considering the high risk that concurred in so high technical jump, it should be ordered as a safety measure a second ICBM program. In the beginning nothing was done, but in 1955 the picture was different. Some of the basic characteristics of the Atlas, albeit valid, could be improved. A new ICBM could be more efficient if it had two phases in tandem, the second of which would be ignited in conditions near the vacuum, in the very high atmosphere. Instead of a thin inflatable deposit, it should have an autostabilized structure made of a light alloy, allowing the missile to be stored in vertical position without requiring pressurization, either with filled or empty deposits. And it was considered that such structure would allow a higher acceleration in the launching. In 1956 it was perceived as well that a new ICBM should have an exclusively inertial guide system and be emplaced in an undergroud silo. So, the WS-107A-2, the same weapon system than the Atlas, but with the sufix "2", was ordered in October 1955, being awarded the main contract for its development to the Martin Company.

Samely as Convair did, Martin built a new assembly plant, in this case in the outskirts of Denver, in Colorado, specifically designed for building this second ICBM, which received the denomination SM-68. In 1958 the provided inertial guide system - which received the name Titan - was installed in the first ICBM - the Atlas - and it was provided in turn with the tricky, albeit probably more precise, radio-inertial system that had been developed for the Atlas. However, to spend even more money, it was redesigned by different contractors. Western Electric was in charge of the main ensemble of the guide system while the Sperry radar and the new computer of digital technology were assigned to Remington Rand Univac. There were many troubles and no Titan missile could fly before the 6th February 1959, operating only with the first phase, which had an engine Aerojet LR 87-1 fed with liquid oxygen and RP-1 fuel, with two combustion chambers that provided 68040 kilograms of thrust each, while the second phase was ballasted with water.

During the following year there were many failures, but the 2nd February 1960 the Titan B-7A performed a 3540-kilometer flight, a distance limited by the amount of propellers, with operative radio guide. In the late 1961, the crews of the Strategic Air Command (SAC) had performed 31 flights from a total of 41 training launchings and trials that were carried in Vanderberg Airbase. Operative status was reached in Lowry Airbase, near Denver, the 18th April 1962, when the missile had already received its new denomination HGM-25A. The training Titan USM-68A became then the HTM-25B. The propulsion of the second phase was effectuated by an Aerojet LR 91-1, which provided a thrust in vacuum conditions equivalent to 36288 kilograms, with an expansion radius in the nozzle of 25:1 configured for operating in the vacuum (because these ballistic missiles made the most part of their trajectory outside the atmosphere) and with an exhaust for the turbo-pump in the middle of the four nozzles, providing turning and adjustment control by means of Vernier engines.

The nuclear warhead of four megatons, the most powerful used until then in the United States, was housed in an atmosphere-reentry vehicle Avco Mk 4. Reaction time was reduced to twenty minutes by means of an extraordinarily rapid fuelling and its ascension from the bottom of the silo at high speed, before the launching in the surface once the fuel deposits of the different phases would have been filled. The deployment of HGM-25A was completed in the early 1963. There was in total six squadrons of the SAC provided each one with nine missiles. Two squadrons were deployed in Lowry and one in each one of the following bases: Beale (California), Mountain Home (Idaho), Ellsworth (South Dakota) and Larson (Washington State). All of them belonged to the 15th Air Force. The Titan I ceased to be operative in 1966. Like the Atlas, it had been surpassed by a galloping technical progress.


The Titan I was projected for being launched from a silo, but before its launching it had to be raised to the surface to be loaded with fuel.

It could be expected that in such a new field as the ICBM not everything could be done right at the first try. The launching of the Sputnik I - first artificial satellite in History -, in October 1957, was a shock for the Americans and immediately the vulnerability and prolonged reaction time of the ICBM of the SAC was recognized as a serious deficiency. In the early 1958, the Martin Company proposed an improved Titan that would use storable propellant so it would be ready in any moment for its immediate launching. In the late year, the company was granted a contract for an even more advanced project, the SM-68B Titan II. Almost the only characteristic shared with the Titan I was the diameter of the first phase. In the new missile this phase was 2.13 meters longer and the second phase had the same diameter than the first one. This allowed the missile to occupy the same silo than its predecessor while its launching weight had been increased in a 50 percent.

Thanks to the subcontractor Aerojet-General, the rocket engines - based in the ones installed in the Titan I - burned Aerozine 50 (a compound of hydrazines) and nitrogen oxide, which could be loaded in the missile and kept there during months without problems of ebullition, evaporation, corrosion or any other. The engine LR 87-5 of the first phase had two combustion chambers, each of which provided 97978 kilograms of thrust. The engine LR 91-5 of the second phase had a sole chamber, which provided 45360 kilograms of thrust. The expansion radius of the nozzle was no lesser than 45:1. Overall, such force allowed the Titan II to double the payload of the Titan I in a same length. A later very important progress was that the Titan II was projected for being launched from the bottom of the silo, which was provided with a powerful W-shaped flame deflector, which from the base directed the flames and smoke towards the exterior through inclined exhaust ducts. Such system caused that in the launching of a Titan II the missile left the silo between two huge oblique smoke colums. These changes in respect of the previous model reduced reaction time to only 60 seconds.

Also it was used a new inertial guide system, simplifying significantly the launching complex and improving flight prestations. The main contractors were IBM and AC Spark Plug. It was also very important the advantage of the Titan II of being able to carry a much larger reentry vehicle. The final model was the General Electric Mk 6, with a nuclear warhead of 18 megatons, much more powerful than in any other American missile. Thanks to the previous experiences, the program of the Titan II was quickly developed. The first prototype was launched in November 1961 and the whole system reached all the objectives besought the 16th March 1962. Operative status was achieved in 1963, when the system had already been denominated LGM-25C. Overall, were deployed 54 Titan II, in six squadrons having each one three triple complexes very separated each other. In 1983, almost all of them remained in service. Two were entrusted to the Davis-Monthan Air Force Base, in Arizona, adhered to the 15th Air Force of the SAC. Other two were entrusted to the Little Rock Airbase, in Arkansas, and the two remaining to the McDonnell Airbase, in Kansas. These four squadrons were adhered to the 2nd Air Force.

Albeit all the first American ICBM had a short lifespan, the Titan II remained in service more than 20 years. For this to be possible, these missiles had to be continually improved. In the late 1970s they were fitted with a new guide system, which was finally installed in 1981. Said system replaced the parts that had been left outdated, such as the original computer of logic modules. The Titan II - reduced to 52 because of an accident that destroyed two of them in the early 1980s - were retired from service after the introduction of the new American ICBM, the MX, later denominated Peacekeeper. Its long permanence in service was caused by the strong increment of Soviet ICBM, which circa 1970 achieved to equal the force of American ICBM and along the decade grew to the point of widely surpassing their rivals. The original idea was to retire the Titan II from 1973, according to an offical announcement of the Department of Defense of 1970, but their real decommissioning did not start until the mid 1980s.


The Titan II was the largest missile deployed in the West and it could be launched from inside its silo. The two columns of smoke, which seem to emerge from the ground, correspond to the side upper ends of a W-shaped deflector for the rockets exhaust smoke. A launching of a Titan I performed the 3rd May 1961 in Vanderberg Airbase from the first silo equipped with such deflector demonstrated that it was possible to effectuate a launching from inside a silo.



Specifications for Titan I



Specifications for Titan II

Categories: Missiles - Cold War - 20th Century - [General] - [General]

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Article submitted: 2015-01-06