Overview
The Centaur (SSB-8) is the United State’s first and most powerful upper-stage rocket. Known as the workhorse of the NASA fleet, it has performed more than 160 launches (168 as of December 18, 2003) in its 40-year history. Although it is most commonly used in conjunction with the Atlas rocket but has also been used in conjunction with the Titan.
The Centaur rocket has been crucial to many aspects of space exploration, including the Mariner missions and the launching of telecommunications satellites such at INTELSTAT. It continues to be used today.
Technical Specifications
Length:
Centaur A, B ,C , D , D1A, D1AR, I: 9.10m (30 ft)
Centaur II, II A, III A: 10.06m (33.2 ft)
Centaur IIIB, IIIB DEC, IIIB SEC: 10.68m (35.2ft)
Centaur D1T: 9.6m (31.5 ft)
Centaur T: 9.0m (29.5 ft)
Diameter:Most versions: 3.05m (10 ft)Centaur T: 4.3m (14.1 ft)
Thrust:
Centaur A, B ,C: 133,453 N (30,000 lbf)
Centaur D , D1A, D1AR, D1T: 131,227 N (29,500 lbf)
Centaur I, II, T: 146,810 N (33,000 lbf)
Centaur IIA: 185,019 N (41,600 lbf)
Centaur III A, IIIB SEC: 99,158 N (22,300 lbf)
Centaur IIIB, IIIBDEC: 198,317 N (44,600 lbf)
Engines: Centaur rockets use two
RL-10 engines, developed by
Pratt & Whitney Aircraft. Some versions (IIIA, IIIA SEC) use only one.
History
The Centaur rocket was not originally developed for NASA. In fact, the preliminary proposals from General Dynamics of San Diego, California were reviewed by the U.S. Air Force in 1957 – one year before NASA was created.
The proposal outlined a boosting system utilizing liquid hydrogen and oxygen, providing a much more powerful boost then given by past rocket vehicles. This power was sorely needed, and quickly – Sputnik was launched in 1957 and the United States was falling behind in the space race.
Development of the Centaur rocket began in 1958, and the project management was taken up by NASA on July 1, 1959. The first test launch was set to take place in January of 1961 – and the rocket was expected to perform well enough to allow many more launches for the rest of the decade.
This assumption was proven to be incorrect when the first Centaur test rocket exploded 54 seconds after lift off on May 8, 1962. The next test was scheduled for September of 1962. The task of fixing the problem with the vehicle was given to Dr. Abe Silverstein of the Lewis Research Center in Cleveland, Ohio. The facility’s familiarity with the cryogenic fuels proved to be a great asset – and after ground tests at the Plum Brooke Station in Sandusky, Ohio the first successful launch of the Atlas/Centaur rocket was performed on November 27, 1963.
In 1994 the rights to the Centaur upper stage were sold to Martin Marietta, which in 1995 merged with Lockheed to become Lockheed Martin. The name Centaur is no longer attached to missions that use it as an upper stage.
Missions
The use of the Centaur upper stage has been extensive, at well over 100 launches. Some highlights of its long career follow.
italics indicates an unsuccessful mission
Date, Vehicle, Mission
May 8, 1962, Atlas/Centaur-1, R&D
November 27, 1963, Atlas/Centaur-2, R&D
March 3, 1965, Atlas/Centaur-5, R&D
May 30, 1966 – January 7, 1968, Atlas/Centaur-(in chronological order) (10, 7, 12, 11, 13, 14, 15), Surveyor 1-7
February 24, 1969, Atlas/Centaur-20, Mariner 6
March 27, 1969, Atlas/Centaur-19, Mariner 7
January 25, 1971, Atlas/Centaur-25, Intelsat IV
May 8, 1971, Atlas/Centaur-24, Mariner 8
May 30, 1971, Atlas/Centaur-23, Mariner 9
December 19, 1971 – May 22, 1975, Atlas/Centaur-(26, 28, 31, 32, 33, 35), Intelsat IV
March 2, 1972, Atlas/Centaur-27, Pioneer 10
April 5, 73, Atlas/Centaur-30, Pioneer 11
November 3, 1973, Atlas/Centaur-34, Mariner 10
August 20, 1975 and September 9, 1975, Titan/Centaur-(4, 3), Viking A, B
August 12, 1977 and August 20, 1977, Titan?Centaur-(7,6), Voyager 1,2
May 20, 1978, Atlas/Centaur-50, Pioneer-12
August 8, 1978, Atlas/Centaur-51, Pioneer-13
April 13, 1994 – October 15 1997, Atlas/Centaur-(73,77,79), GOES-(8,9,10)
October 15, 1997, Titan/Centaur-21, Cassini
December 12, 1998, Titan/Centaur-9, Mercury-3
Accidents / Failed Missions
Atlas/Centaur-1: Suborbital test. Payload shroud collapsed.
Atlas/Centaur-3: Test. Centaur experienced hydraulic failure.
Atlas/Centaur-5: Surveyor 1. Exploded on launch pad.
Atlas/Centaur-17: ATS 4. Second ignition failed.
Atlas-Centaur-21: OAO B. Payload shroud did not separate
Atlas-Centaur-24: Mariner 8. Centaur guidance failure
Titan/ Centaur-1: SPINX and VIKING-DS. Centaur failure.
Atlas/Centaur-33: INTELSTAT-4 6. Atlas failed due to electrical problems.
Atlas/Centaur-43: INTELSTST-4A 5. Atlas booster section turbopump failed
Atlas/Centaur-67: FLTSATCOM 6. Lightning strike.
Atlas/Centaur-70: BS 3h. Centaur did not ignite.
Atlas/Centaur-71: Galaxy 1R. Centaur did not ignite.
Titan/Centaur-9: Mercury 3.
Titan/Centaur-14: Milstar-2 1.
References
Spaceflight Now (http://spaceflightnow.com)
NASA Glenn launch vehicle history (http://www.lerc.nasa.gov/WWW/PAO/html/lvpo.htm)
Gunter’s Space Page (http://www.skyrocket.de/space/space.html)