Titan I SM-68

The SM-68 Titan (individual variants later designated HGM-25 Titan I and LGM-25 Titan II) was the designation of two intercontinental ballistic missiles developed for the United States Air Force. The Titan I and Titan II missiles were operational between 1962 and 1987 during the Cold War. These missiles, particularly the Titan II, were the basis of the Titan family of space launch vehicles.

Titan was originally built as a backup to the SM-65 Atlas. The Titan I used RP-1 and liquid oxygen propellants and required around fifteen minutes to load the rocket and raise it to a launch position. The more powerful Titan II used nitrogen tetroxide and hydrazine, allowing it to be stored with propellant loaded, giving it a much shorter response time.

The Titan I was the first version of the Titan family of rockets. It began as a backup ICBM project in case the Atlas was delayed. It was a two-stage rocket propelled by RP-1 and liquid oxygen. Using RP-1 and LOX meant that the Titan I did not have a quick launch sequence. It took about fifteen minutes to load LOX on the first missile at a complex, raise it topside and launch it, with two other missiles following at about eight-minute intervals. Titan I was operational from early 1962 to mid-1965.

Several US Air Force units operated the Titan I:

568th Strategic Missile Squadron, Larson AFB, Moses Lake, Washington
569th Strategic Missile Squadron, Mountain Home AFB, Mt Home, Idaho
851st Strategic Missile Squadron, Beale AFB, Marysville, California
850th Strategic Missile Squadron, Ellsworth AFB, Rapid City, South Dakota
451st Strategic Missile Wing (formerly 703rd) Lowry AFB, Denver, Colorado

From : Wikipedia