It used an IMU (inertial measurement unit, a gyroscopic sensor) made by ACDelco derived from original designs from MIT Draper Labs.

[5] The Titan rocket family was established in October 1955, when the Air Force awarded the Glenn L. Martin Company a contract to build an intercontinental ballistic missile (ICBM).

The Titan II also used storable propellants: Aerozine 50 fuel, which is a 1:1 mixture of hydrazine and unsymmetrical dimethylhydrazine (UDMH), and dinitrogen tetroxide oxidizer.

[6] The Department of Defense predicted that a Titan II missile could eventually carry a warhead with a 35 megaton yield, based on projected improvements.

[7] The first Titan II launch, Missile N-2, was carried out on 16 March 1962 from LC-16 at Cape Canaveral and performed extremely well, flying 5,000 miles (8,000 km) downrange and depositing its reentry vehicle in the Ascension splash net.

While this did not affect missile launches for the Air Force, NASA officials were concerned that this phenomenon would be harmful to astronauts on a crewed Gemini flight.

The Range Safety officer sent a manual shutdown command to the second stage, causing premature RV separation and impact well short of the intended target point.

The 25 July test (Vehicle N-4) had been scheduled for 27 June, but was delayed by a month when the Titan's right engine experienced severe combustion instability at ignition that caused the entire thrust chamber to break off of the booster and fall down the flame deflector pit, landing about 20 feet from the pad (the Titan's onboard computer shut the engines down the moment loss of thrust occurred).

While it appeared that the pogo problem was largely contained on this flight, the second stage lost thrust again due to a restriction in the gas generator and so only achieved half its intended range.

Meanwhile, combustion instability was still an issue and was confirmed by Aerojet static-firing tests which showed that the LR91 Liquid-propellant engine had difficulty attaining smooth burning after the shock of startup.

The former's primary aim was to develop a missile system, not a launch vehicle for Project Gemini, and they were only interested in technical improvements to the booster insofar as they had relevance to that program.

While adding more pressure to the propellant tanks had reduced vibration, it could only be done so much before putting unsafe structural loads on the Titan and in any case the results were still unsatisfactory from NASA's point of view.

[12] Despite the Air Force's lack of interest in human-rating the Titan II, General Bernard Adolph Schriever assured that any problems with the booster would be fixed.

On 29 March 1963, Schriever invited Space Systems Development (SSD) and BSD officials to his headquarters at Andrews Air Force Base in Maryland, but the meeting was not encouraging.

[13] A closed-door meeting of NASA and Air Force officials led to the former arguing that without any definitive answer to the pogo and combustion instability problems, the Titan could not safely fly human passengers.

During the first week of April, a joint plan was drafted which would ensure that pogo was to be reduced to fit NASA's target and to make design improvements to both Titan stages.

An umbilical cord failed to separate cleanly, ripping out wiring in the second stage which not only cut power to the guidance system, but also prevented the range safety charges from being armed.

[16] The mishap was traced to an unforeseen design flaw in the silo's construction – there was not enough room for the umbilicals to detach properly which resulted in wiring being ripped out of the Titan.

No useful pogo data was obtained due to the early termination of the flight, and the accident was traced to a stress corrosion of the aluminum fuel valve, which resulted in a propellant leak that caught fire from contacting hot engine parts.

[18] The next flight was Missile N-22, a silo test from Vandenberg Air Force Base on 20 June, but once again the second stage lost thrust due to a gas generator restriction.

[18] On the other hand, only Missile N-11 suffered a malfunction due to pogo and the combustion instability issue had occurred in static firings, but not any actual flights.

The trouble appeared to be with Aerojet, and a visit of MSC officials to their Sacramento, California, plant in July revealed a number of extremely careless handling and manufacturing processes.

[20] On 9 August 1965, a fire and resultant loss of oxygen when a high-pressure hydraulic line was cut with an oxyacetylene torch in a missile silo (Site 373–4) near Searcy, Arkansas, killed 53 people, mostly civilian repairmen doing maintenance.

[27] On 20 June 1974, one of two start cartridges failed to ignite due to faulty wiring on a Titan II launch from Silo 395C at Vandenberg AFB in California.

[citation needed] On 24 August 1978, SSgt Robert Thomas was killed at a site outside Rock, Kansas when a missile in its silo leaked propellant.

Because of the hypergolic propellants involved, the entire missile exploded a few hours later, killing an Air Force airman, SrA David Livingston, and destroying the silo (374-7, near Damascus, Arkansas).

The Titan II space launch vehicle is a two-stage liquid fueled booster, designed to provide a small-to-medium weight class capability.

[42] By the mid-1980s, with the stock of refurbished Atlas E/F missiles finally starting to run out, the Air Force decided to reuse decommissioned Titan IIs for space launches.

The Titan 23G ended up being less of a cost-saving measure than anticipated as the expense of refurbishing the missiles for space launches turned out to be more than the cost of flying a brand-new Delta booster.

Unlike refurbished Atlas missiles, which were completely torn down and rebuilt from the ground up, the Titan 23G had relatively few changes aside from replacing the warhead interface and adding range safety and telemetry packages.