Titan (rocket family)
|The Titan rocket family.|
|Role||Expendable launch system with various applications|
|Manufacturer||Glenn L. Martin Company|
|Primary users||United States Air Force
National Aeronautics and Space Administration
|Unit cost||US$250-350 million|
Titan was 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 to Mars, Jupiter, Saturn, Uranus and Neptune.
Titan I 
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 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 Unisys ATHENA computer, designed by Seymour Cray, based in a hardened underground bunker. Using radar data, it made course corrections during the burn phase.
Titan II 
Most of the Titan rockets were the Titan II ICBM and their civilian derivatives for NASA. The Titan II used LR-87-5 engines, a modified version of the LR-87, that relied on a hypergolic combination of nitrogen tetroxide and Aerozine 50 (a 50/50 mix of hydrazine and UDMH) for its oxidizer and fuel instead of the liquid oxygen and RP-1 combination used in the Titan I.
The first Titan II guidance system was built by AC Spark Plug. It used an IMU (inertial measurement unit, a gyroscopic sensor) made by AC Spark Plug derived from original designs from MIT Draper Labs. The missile guidance computer (MGC) was the IBM ASC-15. When spares for this system became hard to obtain, it was replaced by a more modern guidance system, the Delco Universal Space Guidance System (USGS). The USGS used a Carousel IV IMU and a Magic 352 computer.
The most famous use of the civilian Titan II was in the NASA Gemini program of manned space capsules in the mid-1960s. Twelve Titan IIs were used to launch two U.S. unmanned Gemini test launches and ten manned capsules with two-man crews. All of the launches were successes.
Also, in the late 1980s some of the deactivated Titan IIs were converted into space launch vehicles to be used for launching U.S. Government payloads. The final such vehicle launched a Defense Meteorological Satellite Program (DMSP) weather satellite from Vandenberg Air Force Base, California, on 18 October 2003.
Titan III 
The Titan III was a modified Titan II with optional solid rocket boosters. It was developed on behalf of the United States Air Force as a heavy-lift satellite launcher to be used mainly to launch American military payloads and civilian intelligence agency satellites such as the Vela Hotel nuclear-test-ban monitoring satellites, observation and reconnaissance satellites (for intelligence-gathering), and various series of defense communications satellites.
The Titan IIIA was a prototype rocket booster, which consisted of a standard Titan II rocket with a Transtage upper stage. The Titan IIIB with its different versions (23B, 24B, 33B, and 34B) had the Titan III core booster with an Agena D upper stage. This combination was used to launch the KH-8 GAMBIT series of intelligence-gathering satellites. They were all launched from Vandenberg Air Force Base, California, due south over the Pacific into polar orbits. Their maximum payload mass was about 7,500 lb (3,000 kg).
The powerful Titan IIIC used a Titan III core rocket with two large strap-on solid-fuel boosters to increase its launch thrust, and hence the maximum payload mass capability. The solid-fuel boosters that were developed for the Titan IIIC represented a significant engineering advance over previous solid-fueled rockets, due to their large size and thrust, and their advanced thrust-vector control systems. The Titan IIID was a derivative of the Titan IIIC, without the upper transtage, that was used to place members of the Key Hole series of reconnaissance satellites into low Earth orbits. The Titan IIIE, the one with an additional 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.
The first guidance system for the Titan III used the AC Spark Plug company IMU (inertial measurement unit) and an IBM ASC-15 guidance computer from the Titan II. For the Titan III, the ASC-15 drum memory of the computer was lengthened to add 20 more usable tracks, which increased its memory capacity by 35%.
The more-advanced Titan IIIC used the Delco Carousel VI IMU and the Magic 352 guidance computer.
Titan IV 
The Titan IV is a "stretched" Titan III with non-optional solid rocket boosters on its sides. The Titan IV could be launched with a Centaur upper stage, the USAF Inertial Upper Stage (IUS), or no upper stage at all. This rocket was used almost exclusively to launch American military or civilian intelligence agency payloads. However it was also used for a purely scientific purpose to launch the NASA - ESA Cassini / Huygens space probe to Saturn in 1997. The primary intelligence agency that needed the Titan IV's launch capabilities was the National Reconnaissance Office, the NRO.
By the time it became available, the Titan IV was the most powerful unmanned rocket produced and used by United States, because the extremely large and powerful Saturn V rocket had not been available for some years. Still, the Titan IV was considered to be quite expensive to manufacture and use. By the time the Titan IV became operational, the requirements of the U.S. Department of Defense and the NRO for launching satellites had tapered off due to improvements in the longevity of reconnaissance satellites, and in addition, the declining foreign threat to the security of the United States that followed the internal disintegration of the Soviet Union.
As a result of these events, and improvements in technology, when including the cost of the ground operations and facilities for the Titan IV at Vandenberg Air Force Base for launching satellites into polar orbits, the unit cost of a Titan IV launch was very high. Titan IVs were also launched from the Cape Canaveral Air Force Station in Florida for non-polar orbits.
Rocket fuel 
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. Several Atlas and Titan I rockets exploded and destroyed their silos. The Martin Company was able to improve the design with the Titan II. The RP-1/LOX combination was replaced by a room-temperature fuel whose oxidizer did not require cryogenic storage. The same first stage rocket engines were used with some modifications. The diameter of the second stage was increased to match the first stage. The Titan II's hypergolic fuel and oxidizer ignited on contact, but they were highly toxic and corrosive liquids. The fuel was Aerozine 50 (a 50/50 mix of hydrazine and UDMH) and the oxidizer was nitrogen tetroxide.
Accidents at Titan II silos 
There were several accidents in Titan II silos resulting in loss of life and/or serious injuries. In August 1965, 53 construction workers were killed when hydraulic fluid used in the Titan II caught fire in a missile silo northwest of Searcy, Arkansas. The liquid fuel missiles were prone to developing leaks of their toxic propellants. One airman was killed at a site outside Rock, Kansas, on August 24, 1978 when a missile in its silo leaked propellant. Later, another site at Potwin, Kansas, leaked fuel and was closed, and there were no fatalities. In September 1980, at another Titan II silo (374-7) near Damascus, Arkansas, a technician dropped a wrench that broke the skin of the missile. Leaking rocket fuel ignited and blew the 8,000 lb nuclear warhead out of the silo. It landed harmlessly several hundred feet away. The 54 Titan II's were replaced in the U.S. arsenal by 50 MX "Peacekeeper" solid-fuel rocket missiles in late 1980s. 54 Titan IIs had been fielded along with some 1000 Minutemen from the mid-1960s through the mid-1980s. Most of the decommissioned Titan II ICBMs were refurbished and used for Air Force space launch vehicles, with a perfect launch success record.
The high cost of using hydrazine and nitrogen tetroxide, along with the special care that was needed due to their toxicity, proved too much compared to the higher-performance liquid hydrogen or RP-1-fueled vehicles (kerosene), with a liquid oxygen oxidizer. Lockheed Martin decided to extend its Atlas family of rockets instead of its more expensive Titans—along with participating in joint-ventures to sell launches on the Russian Proton rocket and the new Boeing-built Delta IV class of medium and heavy-lift launch vehicles. 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 (NRO).
- For the specifications, please see the articles on each variant.
See also 
- Titan Missile Museum
- List of Titan launches
- Haas (rocket)
- Comparison of orbital launchers families
- Comparison of orbital launch systems
- Barton, Rusty (2003-11-18). "Titan 1 Chronology". Titan 1 ICBM History Website. Geocities.com. Archived from the original on 2005-01-23. Retrieved 2005-06-05.
- Stakem, Patrick H. The History of Spacecraft Computers from the V-2 to the Space Station, 2010, PRB Publishing, ASIN B004L626U6
- David K. Stumpf. Titan II: A History of a Cold War Missile Program. University of Arkansas Press, 2000. ISBN 1-55728-601-9 (cloth). Pages 63-67.
- Ray, Justin (October 18, 2003). "U.S. weather satellite finally escapes grasp of hard luck". spaceflightnow.com. Retrieved 2009-10-18.
- Paul O. Larson. "Titan III Inertial Guidance System," page 4.
- A.C. Liang and D.L. Kleinbub. "Navigation of the Titan IIIC space launch vehicle using the Carousel VB IMU." AIAA Guidance and Control Conference, Key Biscayne, FL, 20–22 August 1973. AIAA Paper No. 73-905.
- "Escape Route Blocked in Silo Disaster". Ellensburg Daily Record. Associated Press. August 13, 1965. p. 1. Retrieved 2011-01-03.
- "1 killed, 6 injured when fuel line breaks at Kansas Titan missile site". St. Petersburg Times. United Press International. August 25, 1978. p. 4. Retrieved 2009-10-18.
- "Thunderhead Of Lethal Vapor Kills Airman At Missile Silo". The Ledger. Associated Press. August 25, 1978. p. 7. Retrieved 2009-10-18.
- "Light on the Road to Damascus" Time magazine, September 29, 1980. Retrieved 2006-09-12
- David K. Stumpf. Titan II: A History of a Cold War Missile Program. The University of Arkansas Press, 2000. Pages 63–65
- USAF Sheppard Technical Training Center. “Student Study Guide, Missile Launch/Missile Officer (LGM-25).” May 1967. Pages 61–65. Available at WikiMedia Commons: TitanII MGC.pdf
- Larson, Paul O. “Titan III Inertial Guidance System,” in AIAA Second Annual Meeting, San Francisco, 26–29 July 1965, pages 1–11.
- Liang, A.C. and Kleinbub, D.L. “Navigation of the Titan IIIC space launch vehicle using the Carousel VB IMU”. AIAA Guidance and Control Conference, Key Biscayne, FL, 20–22 August 1973. AIAA Paper No. 73-905.
|Wikimedia Commons has media related to: Titan (rocket)|
- Video of a Titan I missile launch
- Video of a Titan II missile launch
- Video of the first Titan III-C launch (June 1965)
- Photo of the last Titan launch, at the APOD archive.
- Titan missiles & variations
- Explosion at 374-7 - Details of the September 1980 Arkansas silo explosion
- Related lists