Launch of a Titan IIIE with Voyager 2
|Function||Expendable launch system|
|Country of origin||USA|
|Height||48 m (157 ft)|
|Diameter||3.05 m (10.0 ft)|
|Mass||632,970 kg (1,395,460 lb)|
|15,400 kg (34,000 lb)|
Heliocentric orbit (TMI)
|3,700 kg (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 kN (1,315,000 lbf)|
|Specific impulse||263 sec|
|Burn time||115 seconds|
|Thrust||2,340 kN (530,000 lbf)|
|Specific impulse||302 sec|
|Burn time||147 seconds|
|Thrust||454 kN (102,000 lbf)|
|Specific impulse||316 sec|
|Burn time||205 seconds|
|Third Stage - Centaur-D|
|Thrust||131 kN (29,000 lbf)|
|Specific impulse||444 sec|
|Burn time||470 seconds|
|Fourth Stage (optional) - Star-37E|
|Thrust||68 kN (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 enabled several high-profile NASA missions, including the Voyager and Viking planetary probes, and the joint West German-US Helios spacecraft. All seven launches were conducted from Launch Complex 41 at Cape Canaveral.
The Titan IIIE was the largest and most powerful US launch vehicle yet developed for robotic exploration of the Solar System. While NASA had considered using the Titan IIIC and Transtage, development problems with Transtage led to the decision to integrate Centaur with Titan. However, Centaur had been designed for the very different Atlas vehicle and a number of changes were needed to accommodate it to 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 concern about the heat generated by the Titan's large solid boosters and hypergolic engines, requiring design of an insulation system that would protect Centaur's cryogenic propellants without adding unnecessary weight. 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, but still nothing happened. 12 minutes after liftoff, the range safety destruct command was sent from a radar station in Antigua. The failure was traced to the Centaur boost pumps, but the cause was still unclear, thought likely to be either ice or debris. To reduce the chance of a recurrence of the failure, pre-launch procedures to verify Centaur's pumps were free and unobstructed were put in place. It took nearly four years to trace the cause of the failure to an improperly installed clip inside the LOX tank, which came loose 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
|23E-2||TC-2||Helios-A||Successful||First space probe to orbit closer to the Sun than Mercury.|
|20 August 1975
|23E-4||TC-4||Viking 1||Successful||Carried a lander that landed on Mars.|
|9 September 1975
|23E-3||TC-3||Viking 2||Successful||Carried a lander that landed on Mars.|
|15 January 1976
|23E-5||TC-5||Helios-B||Successful||Holds the record for fastest velocity relative to the Sun achieved by a space probe.|
|20 August 1977
|23E-7||TC-7||Voyager 2||Successful||Additionally boosted by a Star 37E upper stage.
Flew by Jupiter, Saturn, Uranus and Neptune, completing the Planetary Grand Tour. Now leaving the Solar System.
|5 September 1977
|23E-6||TC-6||Voyager 1||Successful||Additionally boosted by a Star 37E upper stage.
Flew by Jupiter and Saturn. Exited the Solar System heliosphere in 2012. Currently most distant object from Earth.
- 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 (PDF). NASA. pp. 145–146.
Media related to Titan IIIE at Wikimedia Commons