Titan IIIE

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Titan IIIE
Titan 3E Centaur launches Voyager 2.jpg
Launch of a Titan IIIE with Voyager 2
Function Expendable launch system
Manufacturer Martin Marietta
Country of origin USA
Height 48 m (157 ft)
Diameter 3.05 m (10.0 ft)
Mass 632,970 kg (1,395,460 lb)
Stages 3-4
Payload to
15,400 kg (34,000 lb)
Payload to
Heliocentric orbit (TMI)
3,700 kg (8,200 lb)
Associated rockets
Family Titan
Launch history
Status Retired
Launch sites LC-41, Cape Canaveral
Total launches 7
Successes 6
Failures 1
First flight 11 February 1974
Last flight 5 September 1977
Notable payloads Voyager (1 / 2)
Viking (1 / 2)
Boosters (Stage 0) - UA1205
No boosters Two
Engines 1 solid
Thrust 5,849 kN (1,315,000 lbf)
Specific impulse 263 sec
Burn time 115 seconds
Fuel Solid
First Stage
Engines 2 LR87-11
Thrust 2,340 kN (530,000 lbf)
Specific impulse 302 sec
Burn time 147 seconds
Fuel A-50/N2O4
Second Stage
Engines 1 LR91-11
Thrust 454 kN (102,000 lbf)
Specific impulse 316 sec
Burn time 205 seconds
Fuel A-50/N2O4
Third Stage - Centaur-D
Engines 2 RL-10A-3
Thrust 131 kN (29,000 lbf)
Specific impulse 444 sec
Burn time 470 seconds
Fuel LH2/LOX
Fourth Stage (optional) - Star-37E
Engines 1 solid
Thrust 68 kN (15,000 lbf)
Specific impulse 284 sec
Burn time 42 seconds
Fuel Solid

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,[1] 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.[2] Star-37E stages were also used on the two Voyager launches, but were considered to be part of the payload rather than the rocket.[3]

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.[4] 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.

Launch History[edit]

Date/Time (GMT) S/N Payload Outcome Remarks
Titan Centaur
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.


Schematics of Titan IIIE with two solid rocket motors (Stage 0) and the Titan III core vehicle Stages I and II


  1. ^ Wade, Mark. "Titan". Encyclopedia Astronautica. Retrieved 2009-01-25. 
  2. ^ Krebs, Gunter. "Titan-3E Centaur-D1T Star-37E". Gunter's Space Page. Retrieved 2009-01-25. 
  3. ^ Krebs, Gunter. "Titan-3E Centaur-D1T". Gunter's Space Page. Retrieved 2009-01-25. 
  4. ^ Dawson, Virginia; Bowles, Mark (2004). Taming Liquid Hydrogen: The Centaur Upper Stage Rocket 1958-2002 (PDF). NASA. pp. 145–146. 

External links[edit]

Media related to Titan IIIE at Wikimedia Commons