January 1955 marked the beginnings of the Titan program. The Titan was to serve a twofold purpose in life. The first objective of the Titan was to serve as a backup to the developing Atlas program. Success of the Atlas was by no means certain at this time. The second object was to develop a two stage missile with a heavier payload capability and longer range than the Atlas.

The Titans were produced by the Glenn L. Martin Company, which later became Martin Marietta, and is now Lockheed Martin.

The first of the Titan family, the Titan I, had an effective range of 10,200 km (6340 miles) and could carry a 1816 kg (3000 lb) payload. It burned RP-1 (rocket grade kerosene) and LOX (liquid oxygen). Guidance was a combination of radio and all-inertial. The first launch of the Titan I as an ICBM was in February 1959, but because of the serious drawback of the launch system (the rocket had to raised from its silo for launching) and the fuel used (it took half an hour to fuel the missile and the fuel wasn't storable), the last of the Titan I's were retired by early 1965.

The Titan II had an increased range of 16,100 km (10,000 miles) and a payload of 3750 kg (8250 lbs). It used A-50 hydrazine (50% mixture of hydrazine, a nitrogen/hydrogen compound, and 50% UDMH, unsymmetrical dimethylhydrazine) and N204 (red fuming nitric acid). This fuel was storable and the Titan II could be launched from its silo. The Titan II began to replace the Titan I in the early 1960's (first launch in April 1962) and continued service into the 1980's (last being retired from service as an ICBM in 1987).

Titan II from silo
Titan II being launched from a silo (USAF photo)

Twelve decommissioned Titan II's were refurbished and used during the Gemini program. Originally fifteen were ordered in 1962 but the last three were cancelled on 30 July 1964.
Serial numbers were 62-12556 thru 62-12570.

Gemini Tital 11
Launch of Gemini XI (NASA photo)

Next came the Titan IIIC. This was an upgrade to the Titan II and was increased to three stages. All three stages used the same fuel as the Titan II (A-50 hydrazine and N204). Two strap on solid propellant boosters were also used. Development began in 1961 with the Titan IIIA and the Titan IIIC first flew on 18 June 1965. The last flight was in March 1982. The Titan IIIC was used by the United States Air Force, but as a space booster, not as an ICBM. The Titan IIIC was capable of lifting 13,100 kg (28,900 lbs) into low Earth orbit, or sending 1200 kg (2650 lbs) to Mars. Besides satellite launches, the Titan IIIC was chosen to be the launch vehicle for Dyna-Soar and the Manned Orbiting Laboratory.

The final member of the Titan family was the Titan IV (including the IVA and IVB). This vehicle was a further upgrade to the Titan IIIC. It was capable of putting 21,680 kg (47,800 lbs) into low Earth orbit, 5,760 kg (12,700 lbs) into geosynchronous orbit, or sending 5,660 kg (12,470 lbs) to escape velocity. It could also insert satellites into a polar low Earth orbit. The fuel used was the same as the Titan II and Titan IIIC vehicles. This vehicle could be configured to fly with all three stages, a single upper stage, or with no upper stages. The first launch of the Titan IIIC was in June 1989, and the final flight took place in October 2005.