Alternative components built for ICBM Atlas missile were used for the SM-68A Titan I missile as a basis, but Martin soon realized that the new missile would have to have at least two stages, so the interior of the missile’s semi-monocoque structure was reinforced. In this way, it was not necessary to have an internal pressurization system and the missile could withstand greater acceleration during takeoff in addition to being able to carry a greater warhead.At first, the development of the Titan I was practically nil, since it was being taken by the USAF as a substitute for Atlas missile if it could not be operational in the planned deadlines or had to be finally canceled. But in October 1957 everything changed, the launching of the Soviet satellite Sputnik revolutionized the defensive strategy of the United States and suddenly the need to have four Atlas Strategic Missile Squadrons (SMS) and four Titan I Strategic Missile Squadrons (SMS) became urgent before 1962 ended.Despite suffering the inconvenience of having to change the inertial guidance system for a radio command guidance system, Martin was able to present the Titan I missile for its first tests in June 1958. In December of that same year the missile was launched for the first time, with the first real stage installed and the second simulated and filled with water. On its fourth launching, in February 1959, the missile successfully completed a 500 km flight. In the seventh test launching, in May 1959, the separation of the stages was achieved and from here onwards the tests began to achieve the maximum range.Unfortunately, after the successful initial launches, luck turned and Titan I suffered a number of setbacks. From May 1959 to January 1960 it was all disasters, exploding a couple of static test vehicles and two explosions of the complete missile when it was on the launch pad. However, at the end of January 1960 the first 3,600 km two stage flight was achieved and a month later the first flight of 8,000 km was successfully made. These successful flights were repeated 4 times during 3 consecutive months, but in July the problems returned and until August 1960 it was not possible for a series J-model missile to carry out another successful flight of 8,000 km.Test launches continued until the end of January 1962, even though by October 1961 a missile squadron had already been emplaced at Lowry AFB, Colorado. The first Titan I missile squadron was declared operational on April 18, 1962 and only 48 hours later were placed on combat alert. Finally, in May 1963 the six projected Strategic Missile Squadrons (SMS) were operational, distributed in three missile complexes per squadron. The complexes were separated from each other, between 15 and 20 km, and had 3 missile silos and a Launch Control center (LCC). The silos were 48 meters deep and had 232 ton doors that protected them from conventional weapons and from overpressures of up to 100 PSI caused by nuclear weapons. The LCC was built at a depth of 15 meters and connected to the missiles by tunnels. Altogether 54 Titan I missile silos were deployed according to a dispersion pattern designated as “3×3”.Despite being fully operational, training launches continued and twelve Titan I missiles were launched in the period 1963-65. The missile was framed in 6 Strategic Missile Squadrons (SMS) deployed in missile complexes located in: -Beale AFB, California (851st SMS) -Ellsworth AFB, South Dakota (850th SMS) -Larson AFB, Washington (568th SMS) -Lowry AFB, Colorado (724th & 725th SMS) -Mountain Home AFB, Idaho (569th SMS).Titan I missile was a two-stage, liquid-fueled ICBM that used RP-1 fuel and liquid oxygen (LOX) that was mixed with an oxidizer. The problem was that the oxidizer had to be charged just before launch with the missile on the surface, outside the silo. Due to this difficulty, the missile took about 20 minutes to be ready to fire from the moment the order was given, and after the first shot, the other missiles could not be fired at intervals of less than 8 minutes. The first stage was 16 meters long, weighed 76.2 tons and had two Aerojet LR87-3 booster engines that generated 1,467 kN (783,378 hp) of thrust and burn during 138 seconds. The second stage measured 9.8 meters in length, weighed 28.9 tons and had one Aerojet LR91-3 sustainer engine that generated 356 kN (190,104 hp) and burn during 225 seconds.This missile was guided by a radio command system that controlled an autopilot that received altitude information through 3 gyroscopes. After being launched, the missile was controlled for a couple of minutes by a pitch programmer that put it in the correct position towards its target. The missile was followed by an AN/GRW-5 guidance radar that passed the position to an AN/GSK-1 (Univac Athena) missile guidance computer located at the Launch Control Center. The guidance computer sent instructions to the missile via guidance radar until the missile exhausted the second stage and it was verified that the missile had reached the proper speed.Once the missile was on the correct trajectory, the guidance system pre-armed the warhead and separated it from the second stage, that was headed for the target. In the event that guidance radar failed, that of another alternative missile complex could be used to guide the missiles and not abort the mission. The warhead was mounted inside an AVCO Mk 4 re-entry vehicle that had mylar balloons as decoys to improve the chances of hitting the target. These decoys mimicked the re-entry vehicle’s radar signature and confused the enemy air defense. The warhead installed on the Titan I ICBM was the 3.75 megaton thermonuclear W-38 with contact or air blast fuze.Because the Titan I missile could not store liquid fuel in its structure, this required much more maintenance and made operations much more dangerous. There was a serious accident in May 1962 and another in August 1964 due to a liquid oxygen leak and a problem during the RP-1 refueling respectively. In addition, the development of new ICBM missiles such as the Minuteman and the Titan II had already begun, so in May 1963 the progressive withdrawal of the Titan I missile was decided. However, the withdrawal of the missile had been scheduled for 1968, but by mid-April 1965 all the missiles had already been removed from the silos and stored. From the 163 Titan I missiles manufactured, 62 were for development and testing and 101 were operational missiles. A total of 49 development missiles and 17 operational missiles were launched.The Titan I missile program cannot be considered a failure, as spectacular progress was made in the development of the following ICBM missiles. But if we take into account that the development cost 1,643 million dollars, each test launch cost 1.5 million and each missile complex cost 170 million, for a weapon that was only in service for 3 years, the analysis cannot be favorable. Furthermore, contrary to what would happen later with Atlas and Titan II missiles, which were used as space rockets after their withdrawal from the USAF, the Titan I missiles were scrapped. Currently, around 30 Titan I missiles are exhibited in different museums and locations, although not all are complete missiles.
