Titan (rocket family)

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.

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 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.