Launch of a Titan IIIE with Voyager 2
|Function||Expendable launch system|
|Country of origin||United States|
|Height||48 metres (157 ft)|
|Diameter||3.05 metres (10.0 ft)|
|Mass||632,970 kilograms (1,395,460 lb)|
|15,400 kilograms (34,000 lb)|
Heliocentric orbit (TMI)
|3,700 kilograms (8,200 lb)|
|Launch sites||LC-41, Cape Canaveral|
|First flight||11 February 1974|
|Last flight||5 September 1977|
|Notable payloads||Voyager (1 / 2)
Viking (1 / 2)
|Boosters (Stage 0) - UA1205|
|Thrust||5,849 kilonewtons (1,315,000 lbf)|
|Specific impulse||263 sec|
|Burn time||115 seconds|
|Thrust||2,340 kilonewtons (530,000 lbf)|
|Specific impulse||302 sec|
|Burn time||147 seconds|
|Thrust||454 kilonewtons (102,000 lbf)|
|Specific impulse||316 sec|
|Burn time||205 seconds|
|Third Stage - Centaur-D|
|Thrust||131 kilonewtons (29,000 lbf)|
|Specific impulse||444 sec|
|Burn time||470 seconds|
|Fourth Stage (optional) - Star-37E|
|Thrust||68 kilonewtons (15,000 lbf)|
|Specific impulse||284 sec|
|Burn time||42 seconds|
The Titan IIIE or Titan 3E, also known as Titan III-Centaur was an American expendable launch system, launched seven times between 1974 and 1977. It was used to launch several high-profile NASA missions, including the Voyager and Viking planetary probes, and the joint West German-US Helios spacecraft.
The Titan IIIE was the largest and most powerful US launch vehicle yet developed for the unmanned space program. While NASA had originally considered using the Transtage, the reliability of it was in doubt, so they went with the proven Centaur. However, Centaur had been designed for the very different Atlas vehicle and a number of changes were needed to accommodate it to the Titan, the biggest being encasing the stage in a large shroud that bulged outward because of the different diameter of the two. There was also the concern that the Titan might generate too much heat because of using hypergolic propellants stored at room temperature and solid rocket motors, and that the Centaur's super-cooled LH2 would get warm enough to turn back into gas. Extra insulation was thus added inside the payload shroud to keep things cool. The Centaur also contained the guidance computer for the entire launch vehicle. A four-stage configuration, with an additional upper stage, a Star-37E, was also available, and was used for the two Helios launches. Star-37E stages were also used on the two Voyager launches, but were considered to be part of the payload rather than the rocket.
The first Titan IIIE launch occurred on February 11, 1974. Original plans were to fly a boilerplate Viking probe, but NASA decided to add a secondary payload: a test satellite called SPHINX (Space Plasma High Voltage Interaction Experiment) which was intended to test the operation of high voltage power supplies in the vacuum of space. The mission was unsuccessful; while the Titan booster performed normally, the Centaur's engines failed to start. Ground controllers waited and issued a manual start command 1:10 seconds later, but still nothing happened. 12 minutes after liftoff, the range safety destruct command was sent from a radar station in Antigua. The cause of the failure was unclear and thought to be either a propellant leak that froze something or a piece of debris obstructing a fuel line, and the only solution to prevent this situation from happening again was performing prelaunch checks of the Centaur's turbopumps to make sure they rotated properly. It took nearly four years to discover the real culprit, which was a workman at Convair who had improperly installed a rivet inside the LOX tank. The rivet then came loose during launch and lodged in one of the boost pumps.Despite the failure, at least one important goal was accomplished in that the bulging Centaur payload shroud was proven to be aerodynamically stable in flight and had jettisoned properly and on schedule. All subsequent launches were successful.
|11 February 1974
|23E-1||TC-1||Sphinx||Failure||Centaur LOX turbopump malfunction. RSO destruct at T+742 seconds.|
|10 December 1974
|20 August 1975
|9 September 1975
|15 January 1976
|20 August 1977
|5 September 1977
- Wade, Mark. "Titan". Encyclopedia Astronautica. Retrieved 2009-01-25.
- Krebs, Gunter. "Titan-3E Centaur-D1T Star-37E". Gunter's Space Page. Retrieved 2009-01-25.
- Krebs, Gunter. "Titan-3E Centaur-D1T". Gunter's Space Page. Retrieved 2009-01-25.
- Dawson, Virginia; Bowles, Mark (2004). Taming Liquid Hydrogen: The Centaur Upper Stage Rocket 1958-2002. NASA. p. 145–146.
Media related to Titan IIIE at Wikimedia Commons
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