Titan vehicles were also used to lift US military payloads as well as civilian agency reconnaissance satellites and to send interplanetary scientific probes throughout the Solar System.

It was a two-stage rocket operational from early 1962 to mid-1965 whose LR-87 booster engine was powered by RP-1 (kerosene) and liquid oxygen (LOX).

The ground guidance for the Titan was the UNIVAC ATHENA computer, designed by Seymour Cray, based in a hardened underground bunker.

It used an inertial measurement unit made by AC Spark Plug derived from original designs from the Charles Stark Draper Laboratory at MIT.

[4] Liquid oxygen is dangerous to use in an enclosed space, such as a missile silo, and cannot be stored for long periods in the booster oxidizer tank.

The Titan II's hypergolic fuel and oxidizer ignited on contact, but they were highly toxic and corrosive liquids.

In September 1980, at Titan II silo 374-7 near Damascus, Arkansas, a technician dropped an 8 lb (3.6 kg) socket that fell 70 ft (21 m), bounced off a thrust mount, and broke the skin of the missile's first stage,[11] over eight hours prior to an eventual explosion.

[12] The puncture occurred about 6:30 p.m.[13] and when a leak was detected shortly after, the silo was flooded with water and civilian authorities were advised to evacuate the area.

[14] As the problem was being attended to at around 3 a.m.,[13] leaking rocket fuel ignited and blew the 8,000 lb (3,630 kg) nuclear warhead out of the silo.

[13][19] The explosion blew the 740-ton launch tube cover 200 ft (60 m) into the air and left a crater 250 feet (76 m) in diameter.

The most famous use of the civilian Titan II was in the NASA Gemini program of crewed space capsules in the mid-1960s.

[28] The more-advanced Titan IIIC used a Delco Carousel VB IMU and MAGIC 352 Missile Guidance Computer (MGC).

[citation needed] The Titan IIIE, with a high-specific-impulse Centaur upper stage, was used to launch several scientific spacecraft, including both of NASA's two Voyager space probes to Jupiter, Saturn and beyond, and both of the two Viking missions to place two orbiters around Mars and two instrumented landers on its surface.

Derived from the Titan 34D and originally proposed as a medium-lift expendable launch system for the US Air Force, who selected the Delta II instead.

The primary intelligence agency that needed the Titan IV's launch capabilities was the National Reconnaissance Office (NRO).

When it was being produced, the Titan IV was the most powerful uncrewed rocket available to the United States, with proportionally high manufacturing and operations expenses.

As a result of these events and improvements in technology, the unit cost of a Titan IV launch was very high.

Additional expenses were generated by the ground operations and facilities for the Titan IV at Vandenberg Air Force Base for launching satellites into polar orbits.

The Titan IVB was the last Titan rocket to remain in service, making its penultimate launch from Cape Canaveral on 30 April 2005, followed by its final launch from Vandenberg Air Force Base on 19 October 2005, carrying the USA-186 optical imaging satellite for the National Reconnaissance Office.