Centaur (rocket stage)

Centaur III
	A single-engine Centaur III being raised for mating to an Atlas V rocket
Manufacturer	United Launch Alliance
Used on	Current Atlas V: Centaur III Vulcan: Centaur V Historical Atlas-Centaur Saturn I Titan III Titan IV Atlas II Atlas III Shuttle-Centaur(not flown)
General characteristics
Height	12.68 m (499 in)
Diameter	3.05 m (120 in)
Propellant mass	20,830 kg (45,920 lb)
Empty mass	2,247 kg (4,954 lb), single engine; 2,462 kg (5,428 lb), dual engine
Centaur III
Powered by	1 or 2 RL10
Maximum thrust	99.2 kN (22,300 lbf), per engine
Specific impulse	450.5 seconds (4.418 km/s)
Burn time	Variable
Propellant	LH2 / LOX
Associated stages
Derivatives	Centaur V; Advanced Cryogenic Evolved Stage
Launch history
Status	Active
Total launches	271 as of January 2024
First flight	May 9, 1962

The Centaur is a family of rocket propelled upper stages that has been in use since 1962. It is currently produced by U.S. launch service provider United Launch Alliance, with one main active version and one version under development. The 3.05 m (10.0 ft) diameter Common Centaur/Centaur III flies as the upper stage of the Atlas V launch vehicle, and the 5.4 m (18 ft) diameter Centaur V has been developed as the upper stage of ULA's new Vulcan rocket.^[4]^[5] Centaur was the first rocket stage to use liquid hydrogen (LH₂) and liquid oxygen (LOX) propellants, a high-energy combination that is ideal for upper stages but has significant handling difficulties.^[6]

^ "Altas V Launch Services User's Guide" (PDF). United Launch Alliance. March 2010. Archived from the original (PDF) on March 6, 2012. Retrieved July 9, 2015.
^ Cite error: The named reference GSPCentaur was invoked but never defined (see the help page).
^ NASA (n.d.). "SPC Centaur Testing". Retrieved February 12, 2012.
^ Berger, Eric (December 11, 2018). "Getting Vulcan up to speed: Part one of our interview with Tory Bruno". Ars Technica. Retrieved December 12, 2018. Centaur 3 (which flies on the Atlas V rocket) is 3.8 meters in diameter. The very first Centaur we fly on Vulcan will go straight to 5.4 meters in diameter.
^ "Vulcan Centaur". United Launch Alliance. 2018. Retrieved December 12, 2018.
^ Helen T. Wells; Susan H. Whiteley; Carrie E. Karegeannes. "Launch Vehicles". Origin of NASA Names. NASA Science and Technical Information Office. p. 11. Archived from the original on July 14, 2019. Retrieved March 29, 2019. because it proposed to make first use of the theoretically powerful but problem-making liquid hydrogen as fuel.

[Altas5Users-1] "Altas V Launch Services User's Guide" (PDF). United Launch Alliance. March 2010. Archived from the original (PDF) on March 6, 2012. Retrieved July 9, 2015.

[GSPCentaur-2] Cite error: The named reference GSPCentaur was invoked but never defined (see the help page).

[3] NASA (n.d.). "SPC Centaur Testing". Retrieved February 12, 2012.

[ars20171211-4] Berger, Eric (December 11, 2018). "Getting Vulcan up to speed: Part one of our interview with Tory Bruno". Ars Technica. Retrieved December 12, 2018. Centaur 3 (which flies on the Atlas V rocket) is 3.8 meters in diameter. The very first Centaur we fly on Vulcan will go straight to 5.4 meters in diameter.

[ulaVulcanCentaur-5] "Vulcan Centaur". United Launch Alliance. 2018. Retrieved December 12, 2018.

[6] Helen T. Wells; Susan H. Whiteley; Carrie E. Karegeannes. "Launch Vehicles". Origin of NASA Names. NASA Science and Technical Information Office. p. 11. Archived from the original on July 14, 2019. Retrieved March 29, 2019. because it proposed to make first use of the theoretically powerful but problem-making liquid hydrogen as fuel.

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