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Vulcan Centaur
Vulcan Centaur is a heavy-lift launch vehicle developed and operated by United Launch Alliance (ULA). It is a two-stage-to-orbit launch vehicle consisting of the Vulcan first stage and the Centaur second stage. Replacing ULA's Atlas V and Delta IV rockets, the Vulcan Centaur is principally designed to meet the needs of the National Security Space Launch (NSSL) program, which supports U.S. intelligence agencies and the Defense Department, but ULA believes it will also be able to price missions low enough to attract commercial launches.
ULA began development of the new launch vehicle in 2014, primarily to compete with SpaceX’s Falcon 9 and to comply with a Congressional mandate to phase out the use of the Russian-made RD-180 engine that powered the Atlas V. The first launch of the Vulcan Centaur was initially scheduled for 2019 but faced multiple delays due to developmental challenges with its new BE-4 first-stage engine and the Centaur second-stage.
The Vulcan Centaur had a near perfect first launch on January 8, 2024, carrying the Peregrine lunar lander, the first mission of NASA's Commercial Lunar Payload Services program. Its second launch, a NSSL certification flight, took place on October 4, 2024, which achieved an acceptable orbital insertion, despite the nozzle on one of the GEM-63XL solid rocket boosters falling off which led to reduced, asymmetrical thrust. Following a five-month review of the launches, the Space Force certified the Vulcan for NSSL missions in March 2025.
The Vulcan Centaur re-uses many technologies from ULA's Atlas V and Delta IV launch vehicles, with an aim to achieve better performance and lower production costs. Also, unlike vertically integrated competitors like SpaceX and Blue Origin, ULA (itself a joint venture between Boeing and Lockheed Martin) relies heavily on subcontractors to build major components of the rocket.
The Vulcan's first stage shares a common heritage with the Delta IV's Common Booster Core. It is built in the same Decatur, Alabama factory using much of the same manufacturing equipment, but is about 0.3 meters (1 ft) larger in diameter. The most significant change in the first stage is its use of liquid methane (liquefied natural gas) as fuel in two BE-4 engines developed by Blue Origin. Compared to the liquid hydrogen used on the Delta IV, methane is denser and has a higher boiling point, allowing for smaller, lighter fuel tanks. It also burns cleaner than the kerosene used in the Atlas V, reducing hydrocarbon buildup in engines, which would facilitate refurbishment under the proposed SMART reuse system.
The rocket's second stage, the Centaur V, is an upgraded version of the Centaur III used on the Atlas V offering enhanced performance. It is powered by two RL10 engines from Aerojet Rocketdyne, fueled by liquid hydrogen.
To further enhance payload capacity, the Vulcan Centaur can be equipped with up to six GEM 63XL SRBs (solid rocket boosters) from Northrop Grumman—a lengthened version of the GEM 63 SRBs used on the Atlas V.
A single-core Vulcan Centaur with six SRBs delivers heavy-lift capabilities comparable to the larger and more expensive three-core Delta IV Heavy. With a single core and six GEM boosters, the Vulcan Centaur can lift 27,200 kilograms (60,000 lb) to low Earth orbit (LEO), surpassing the Atlas V's maximum of 18,850 kg (41,560 lb) with a single core and five GEM boosters, and approaching the 28,790 kg (63,470 lb) capacity of the three-core Delta IV Heavy.
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Vulcan Centaur
Vulcan Centaur is a heavy-lift launch vehicle developed and operated by United Launch Alliance (ULA). It is a two-stage-to-orbit launch vehicle consisting of the Vulcan first stage and the Centaur second stage. Replacing ULA's Atlas V and Delta IV rockets, the Vulcan Centaur is principally designed to meet the needs of the National Security Space Launch (NSSL) program, which supports U.S. intelligence agencies and the Defense Department, but ULA believes it will also be able to price missions low enough to attract commercial launches.
ULA began development of the new launch vehicle in 2014, primarily to compete with SpaceX’s Falcon 9 and to comply with a Congressional mandate to phase out the use of the Russian-made RD-180 engine that powered the Atlas V. The first launch of the Vulcan Centaur was initially scheduled for 2019 but faced multiple delays due to developmental challenges with its new BE-4 first-stage engine and the Centaur second-stage.
The Vulcan Centaur had a near perfect first launch on January 8, 2024, carrying the Peregrine lunar lander, the first mission of NASA's Commercial Lunar Payload Services program. Its second launch, a NSSL certification flight, took place on October 4, 2024, which achieved an acceptable orbital insertion, despite the nozzle on one of the GEM-63XL solid rocket boosters falling off which led to reduced, asymmetrical thrust. Following a five-month review of the launches, the Space Force certified the Vulcan for NSSL missions in March 2025.
The Vulcan Centaur re-uses many technologies from ULA's Atlas V and Delta IV launch vehicles, with an aim to achieve better performance and lower production costs. Also, unlike vertically integrated competitors like SpaceX and Blue Origin, ULA (itself a joint venture between Boeing and Lockheed Martin) relies heavily on subcontractors to build major components of the rocket.
The Vulcan's first stage shares a common heritage with the Delta IV's Common Booster Core. It is built in the same Decatur, Alabama factory using much of the same manufacturing equipment, but is about 0.3 meters (1 ft) larger in diameter. The most significant change in the first stage is its use of liquid methane (liquefied natural gas) as fuel in two BE-4 engines developed by Blue Origin. Compared to the liquid hydrogen used on the Delta IV, methane is denser and has a higher boiling point, allowing for smaller, lighter fuel tanks. It also burns cleaner than the kerosene used in the Atlas V, reducing hydrocarbon buildup in engines, which would facilitate refurbishment under the proposed SMART reuse system.
The rocket's second stage, the Centaur V, is an upgraded version of the Centaur III used on the Atlas V offering enhanced performance. It is powered by two RL10 engines from Aerojet Rocketdyne, fueled by liquid hydrogen.
To further enhance payload capacity, the Vulcan Centaur can be equipped with up to six GEM 63XL SRBs (solid rocket boosters) from Northrop Grumman—a lengthened version of the GEM 63 SRBs used on the Atlas V.
A single-core Vulcan Centaur with six SRBs delivers heavy-lift capabilities comparable to the larger and more expensive three-core Delta IV Heavy. With a single core and six GEM boosters, the Vulcan Centaur can lift 27,200 kilograms (60,000 lb) to low Earth orbit (LEO), surpassing the Atlas V's maximum of 18,850 kg (41,560 lb) with a single core and five GEM boosters, and approaching the 28,790 kg (63,470 lb) capacity of the three-core Delta IV Heavy.
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