Titan rocket

Titan family
The Titan rocket family.
Role	Expendable launch system with various applications
Manufacturer	Glenn L. Martin Company
First flight	1958-12-20
Introduction	1959
Retired	2005
Primary users	United States Air Force National Aeronautics and Space Administration
Produced	1957–2000s (decade)
Number built	368
Unit cost	US$250–350 million
Variants	Titan I Titan II Titan IIIA Titan IIIB Titan IIIC Titan IIID Titan IIIE Titan 34D Titan IV

Titan is a family of U.S. expendable rockets used between 1959 and 2005. A total of 368 rockets of this family were launched, including all the Project Gemini manned flights of the mid-1960s. Titans were part of the American intercontinental ballistic missile deterrent until the late 1980s, and lifted other American military payloads as well as civilian agency intelligence-gathering satellites. Titans also were used to send highly successful interplanetary scientific probes throughout the Solar System.

The HGM-25A 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 whose LR-87 engine was powered by RP-1 and liquid oxygen. It was operational from early 1962 to mid-1965. The ground guidance for the Titan was the UNIVAC ATHENA computer, designed by Seymour Cray, based in a hardened underground bunker. Using radar data, it made course corrections during the burn phase.

Unlike decommissioned Thor, Atlas, and Titan II missiles, the Titan I inventory was scrapped and never reused for space launches or RV tests, as all support infrastructure for the missile had been converted to the Titan II/III family by 1965.

Most of the Titan rockets were the Titan II ICBM and their civilian derivatives for NASA. The Titan II used the LR-87-5 engine, a modified version of the LR-87, that relied on a hypergolic propellant combination of nitrogen tetroxide for its oxidizer and Aerozine 50 (a 50/50 mix of hydrazine and UDMH) for its fuel instead of the liquid oxygen and RP-1 combination used in the Titan I.