Support Equipment

Vulcan Centaur

Also known as
  • Vulcan
  • Vulcan rocket
  • ULA Vulcan
  • Vulcan launch system
  • VC2S
  • VC4S
  • VC6L
  • Centaur V

Vulcan Centaur is United Launch Alliance's single-core successor to Atlas V and Delta IV for national-security, civil, science, cargo, and commercial orbital launch missions. Public sources document payload delivery and Space Force launch certification, not direct use as a battlefield weapon in a named conflict.

Vulcan Centaur, Heavy-lift orbital launch vehicle, Support Equipment
Image source: Vulcan Centaur Rollout Image
National-Security Launch Role

Vulcan Centaur's documented military role is orbital launch support rather than direct conflict employment. Space Systems Command certified the launch system for National Security Space Launch missions in March 2025, and later releases describe Vulcan delivering Space Force payloads to geosynchronous orbits.

Certification path

SSC described certification as a multi-year process with two flight demonstrations, payload-interface verification, subsystem design reviews, and hardware/software audits.

USSF-106

The first operational Vulcan NSSL mission carried demonstrations and experiments for DoD customers, including the NTS-3 navigation experiment, to geosynchronous orbit.

USSF-87

SSC and ULA identified USSF-87 as a VC4S mission carrying GSSAP and additional research, development, and training payloads for geosynchronous operations.

Sources: SSC Vulcan Certification; SSC USSF-106 Launch; SSC USSF-87 Launch; Vulcan USSF-87 Mission.

Profile / Specs

Profile

Origin
United States
Type
Heavy-lift orbital launch vehicle
Designer
United Launch Alliance
Produced
2020s-present launch service
Developed from
Atlas V and Delta IV launch-vehicle heritage

Specifications

Architecture
Single-core Vulcan booster, Centaur V upper stage, and a 5.4 m class payload fairing
Main engines
Two Blue Origin BE-4 engines using liquid oxygen and liquefied natural gas; ULA's user guide lists 550,000 lbf sea-level thrust per engine
Upper stage
Centaur V with pressure-stabilized stainless-steel tanks and two restartable RL10C engines in the 2023 user guide baseline
Solid rocket boosters
Zero, two, four, or six Northrop Grumman GEM 63XL solid rocket boosters; ULA lists two- and six-booster versions as standard offerings
Payload fairings
Standard 15.5 m (51 ft) or long 21.3 m (70 ft) payload fairing options
Mission market
ULA material identifies commercial, civil, science, cargo, and national-security space customers
NSSL status
Space Systems Command certified Vulcan for National Security Space Launch missions on March 26, 2025
Launch sites
ULA lists Space Launch Complex-41 at Cape Canaveral Space Force Station and Space Launch Complex-3E at Vandenberg Space Force Base for Vulcan launch operations
Launch Vehicle Lineage

ULA presents Vulcan Centaur as a new launch vehicle built from selected Atlas V and Delta IV experience rather than a variant of either older system. The user guide ties Vulcan's reliability model, fairing practice, avionics, Centaur upper-stage heritage, booster sizing, GEM 63XL booster path, and launch sites to those earlier ULA families.

  • Atlas V: ULA identifies Atlas V heritage in Vulcan's Centaur, avionics, fairing, and launch-site choices.
  • Delta IV Medium+ (4,2): this two-booster Delta IV Medium+ configuration is one public example of the broader Delta IV family whose booster and reliability history feed Vulcan's design context.

Sources: Vulcan Launch Systems User's Guide; Vulcan Centaur Overview.

Configuration Logic

The public Vulcan designation system is compact: VC identifies the Vulcan booster and Centaur V upper stage, the third character records the solid-rocket-booster count, and the final letter identifies the standard or long payload fairing. ULA's user guide lists zero, two, four, and six-booster combinations, with 15.5 m standard and 21.3 m long fairing options.

Booster

The first stage uses two BE-4 engines burning liquid oxygen and liquefied natural gas.

Upper stage

Centaur V is the cryogenic second stage, with restartable RL10 engines and stainless-steel pressure-stabilized tanks in ULA's 2023 guide.

Boosters

GEM 63XL solid rocket boosters are added in mission-specific sets; ULA lists two- and six-booster versions as the standard offerings.

Fairings

Standard and long 5.4 m fairings let the same core architecture cover different spacecraft volume requirements and multi-manifest missions.

Sources: Vulcan Launch Systems User's Guide; Vulcan Centaur Overview; Vulcan Rocket.

Variants

ULA's Vulcan naming convention uses VC for the Vulcan booster and Centaur V upper stage, a third character for the number of GEM 63XL solid rocket boosters, and S or L for the standard or long payload fairing.

VariantConfigurationDesignation notes
VC2STwo solid rocket boosters, standard payload fairing

ULA's user guide gives VC2S as the example configuration, and the January 2024 Cert-1 mission used a Vulcan VC2S vehicle.

Sources: Vulcan Launch Systems User's Guide, Vulcan Centaur Overview

VC4SFour solid rocket boosters, standard payload fairing

Space Systems Command identified the USSF-87 mission as a VC4S launch with Centaur V, four solid rocket motors, and the standard payload fairing.

Sources: SSC USSF-87 Launch

VC6LSix solid rocket boosters, long payload fairing

ULA's configuration key allows six-booster and long-fairing combinations for higher-performance or larger-volume missions.

Sources: Vulcan Launch Systems User's Guide

Timeline

Vulcan Centaur Key Events

  1. Vulcan Cert-1 mission

    NASA image provenance and ULA mission material identify the January 2024 Peregrine mission as an early Vulcan launch from Space Launch Complex 41.

  2. National-security launch certification

    Space Systems Command announced Vulcan certification for National Security Space Launch missions after two flight demonstrations and extensive vehicle, interface, subsystem, hardware, and software reviews.

  3. USSF-106 first operational NSSL mission

    Space Systems Command reported that Vulcan delivered the USSF-106 demonstrations and experiments to geosynchronous orbit for DoD customers.

  4. USSF-87 national-security launch

    ULA reported that a Vulcan rocket launched the USSF-87 mission for the U.S. Space Force's Space Systems Command from Cape Canaveral.

Media

Vulcan Centaur Images

Vulcan Centaur, Heavy-lift orbital launch vehicle, Support Equipment - view 1
Source: ULA Vulcan Rocket Unveiled at SLC-41 Image
Vulcan Centaur, Heavy-lift orbital launch vehicle, Support Equipment - view 2
Source: Vulcan Centaur Rollout Image
Related Weapon Systems
Project 58181 / Project 58503 Centaur-LK fast assault craft, Armored fast assault / landing craft, Naval SystemsNaval SystemsProject 58181 / Project 58503 Centaur-LK fast assault craftArmored fast assault / landing craftProject 58181 Centaur began as a Ukrainian armored landing-craft design derived from the Gyurza-M gunboat lineage and was revised during construction into Project 58503 Centaur-LK. Built at Kuznya na Rybalskomu for the Ukrainian Navy, the class combines a bow-ramp troop compartment, waterjet propulsion, armored crew and landing spaces, remote weapon stations, 80 mm rocket launchers, and wartime use as a small assault, evacuation, minelaying, and fire-support craft.
X-37B Orbital Test Vehicle, Reusable unmanned orbital test vehicle, Support EquipmentSupport EquipmentX-37B Orbital Test VehicleReusable unmanned orbital test vehicleThe X-37B Orbital Test Vehicle is a Boeing-built, uncrewed autonomous spaceplane operated for U.S. government orbital experimentation by the Department of the Air Force and U.S. Space Force. Public mission reporting describes it as a returnable test platform that has launched on Atlas V, Falcon 9, and Falcon Heavy rockets, landed autonomously at runway sites, and flown eight missions as of the OTV-8 launch in August 2025.
Space-Based Infrared System / SBIRS, Missile-warning satellite constellation, Support EquipmentSupport EquipmentSpace-Based Infrared System / SBIRSMissile-warning satellite constellationSpace-Based Infrared System (SBIRS) is the U.S. Space Force space-based missile-warning constellation that replaced Defense Support Program coverage with geosynchronous satellites, highly elliptical orbit payloads, and consolidated ground processing. Lockheed Martin led the space and ground system, Northrop Grumman supplied infrared payloads, and official reporting says SBIRS provided early warning during Iran's April 2024 missile and drone attack on Israel.

Sources

Vulcan RocketPublisher: United Launch Alliance | Note: Supports Vulcan Centaur manufacturer context, BE-4 engines, LNG/LO2 propellants, optional GEM 63XL solid rocket boosters, and configuration details. | Accessed: 2026-07-13Vulcan Defense LaunchPublisher: United Launch Alliance | Note: Supports the USSF-87 mission, Space Launch Complex-41 launch location, national-security launch context, and ULA's statement that its Atlas, Delta, and Vulcan legacy supports Space Force and NRO missions. | Accessed: 2026-07-13Vulcan Launch Systems User's GuidePublisher: United Launch Alliance | Note: Supports Vulcan Centaur configuration naming, BE-4 thrust, Centaur V baseline, GEM 63XL booster counts, fairing lengths, launch sites, and Atlas V/Delta IV heritage. | Accessed: 2026-07-13Vulcan Centaur OverviewPublisher: United Launch Alliance | Note: Supports Vulcan Centaur market context, Atlas V and Delta IV heritage, and public technical overview details. | Accessed: 2026-07-13SSC Vulcan CertificationPublisher: Space Systems Command | Note: Supports March 2025 certification of Vulcan for National Security Space Launch missions and the certification process details. | Accessed: 2026-07-13SSC USSF-106 LaunchPublisher: Space Systems Command | Note: Supports Vulcan's first operational NSSL mission for the U.S. Space Force and delivery of USSF-106 demonstrations and experiments to geosynchronous orbit for DoD customers. | Accessed: 2026-07-13SSC USSF-87 LaunchPublisher: Space Systems Command | Note: Supports the USSF-87 launch, VC4S configuration, GSSAP payload context, and delivery of payloads to designated orbits. | Accessed: 2026-07-13Vulcan USSF-87 MissionPublisher: United Launch Alliance | Note: Supports the USSF-87 mission profile, VC4S configuration, direct-to-geosynchronous-orbit payload delivery, and Space Launch Complex-41 launch location. | Accessed: 2026-07-13Vulcan GEM 63XL BoostersPublisher: United Launch Alliance | Note: Supports GEM 63XL booster dimensions, propellant load, thrust, burn duration, and relationship to Atlas and Delta GEM-motor heritage. | Accessed: 2026-07-13Vulcan Centaur Rollout ImagePublisher: Wikimedia Commons | Note: Supports public-domain NASA image provenance for the Vulcan rollout image used on this page. | Accessed: 2026-07-13ULA Vulcan Rocket Unveiled at SLC-41 ImagePublisher: Wikimedia Commons | Note: Supports public-domain NASA image provenance for a Vulcan pathfinder test article at Space Launch Complex-41. | Accessed: 2026-07-13USSF-87 SSC Image GalleryPublisher: Space Systems Command | Note: Supports public-domain image provenance for a USSF-87 Vulcan launch photograph from Space Launch Complex-41. | Accessed: 2026-07-13