Titan (rocket family)

See also: LGM-25 Titan

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
Number built	368
Variants	Titan I Titan II Titan IIIA Titan IIIB Titan IIIC Titan IIID Titan IIIE Titan 34D Titan IV

Titan was a family of U.S. expendable rockets used between 1959 and 2005. A total of 368 rockets of this family were launched.

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 powered by RP-1 and Liquid Oxygen. It was operational from early 1962 to mid-1965.

Titan II

Most of the Titan rockets were the Titan II ICBM and their civilian derivatives for NASA. The Titan II used a hypergolic combination of nitrogen tetroxide and Aerozine 50 (a 50/50 mix of hydrazine and UDMH) for its oxidizer and fuel.

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 important 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 80s 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 by the U.S. 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 for the intelligence agencies 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 the two sides. The Titan IV could be launched with either the Centaur upper stage, the NASA Inertial Upper Stage (IUS), 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 purely for 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 been no longer 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 extremely 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 communist Soviet Union (the U.S.S.R.).

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. (Remember, however, that not all Titan IVs were launched from Vandenberg. Some of them were launched from the John F. Kennedy Space Center in Florida.

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.

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, but 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. This marked the beginning of the end for the Titan II as an ICBM. 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.

Current status of Titans

File:Last Titan Rocket-Vanderburg AFB.jpg

The last Titan rocket launched, a Titan IV B

As of 2006, the Titan family of rockets is obsolete. 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. The current owners of the Titan family of rockets, the Lockheed-Martin compay, 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 next-to-last Titan rocket was launched successfully from Cape Canaveral on 29 April 2005. The final Titan rocket was launched successfully from Vandenberg Air Force Base on 19 October 2005, carrying a secret payload for the National Reconnaissance Office (NRO). There are about twenty Titan II rockets at the Aerospace Maintenance and Regeneration Center near Tucson, Arizona, that are set to either be scrapped or used as monuments.

A replica of a Titan II rocket is the centerpiece of the Kansas Cosmosphere and Space Center aerospace museum in Hutchinson, Kansas.

Specifications

For the specifications, please see the articles on each variant.

See also

• Titan Missile Museum
• List of Titan launches

References

• 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.

External links

• 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

• List of missiles