Vulcan Centaur is United Launch Alliance's heavy-lift rocket, with two BE-4 engines and up to six solid boosters.
ula-vulcan-centaur Vulcan Centaur is a heavy launcher from United Launch Alliance, built for national security, civil and commercial payloads and flown from Florida and California. Two BE-4 engines power the booster, and zero to six solid boosters can be added. It first flew on 8 January 2024, carrying Astrobotic's Peregrine lunar lander.
The booster's tanks are aluminium orthogrid, walls with a grid of stiffening ribs, welded by a stirring method called friction stir welding. The Centaur V upper stage has a thin stainless steel tank that holds its shape from the pressure inside. The fairing is a graphite-epoxy sandwich around a vented aluminium honeycomb core.
Vulcan Centaur launches national security, civil and commercial payloads from Florida and California. Its materials mix aluminum orthogrid tanks, a pressure stabilized stainless Centaur V tank and a composite fairing.
Orthogrid panels formed in a press brake and spun-formed aluminium domes make up the tanks. Two friction stir welding machines built by PAR Systems join them at ULA's Decatur site. The oxygen and natural gas tanks share a common bulkhead, and the booster holds over a million pounds of propellant.
Two BE-4 engines from Blue Origin burn liquid oxygen and liquefied natural gas, each pushing with 2446.5 kilonewtons at sea level. A propellant utilisation system signals when the booster's propellants run out, and that starts the engines' shutdown sequence. An interstage adapter joins the booster to the Centaur V.
Centaur V is 5.4 metres across and 11.7 metres long and holds 120,000 pounds of propellant. Its hydrogen and oxygen tanks share a common bulkhead and are insulated with spray-on foam, plus blankets and radiation shields for long coasts. Two RL10C-1-1A engines of 23,825 pounds-force each power it.
The fairing is 5.4 metres across, and 15.5 metres long as standard or 21.3 metres in its long form. It is a two-piece shell that separates without debris, on spring packs and a frangible joint built to break cleanly. Acoustic panels cut noise for the payload.
Zero, two, four or six GEM 63XL boosters from Northrop Grumman can be strapped on. Each is a stretched Atlas V GEM 63 with 10 percent more total impulse. The case is graphite-epoxy composite, 63 inches across and 21.9 metres long, and the throttle profile is built into the shape of the propellant grain.
Orthogrid panels and spun-formed domes of the booster tanks, welded by friction stir welding. ULA does not name the alloy.
The thin, pressure-stabilised Centaur V tank. No grade is given.
The vented core of the fairing sandwich, under graphite-epoxy face sheets.
The cases of the GEM 63XL boosters. ULA does not name the resin or fibre.
Insulation on the cryogenic tanks, to limit boil-off in flight. ULA does not name the foam.
Blankets that add insulation to the Centaur V tanks for long coasts.
Two BE-4 engines from Blue Origin power the booster, and two RL10C-1-1A engines power the Centaur V. Northrop Grumman supplies the solid boosters. Vulcan replaces Atlas V and Delta IV Heavy, and it builds on Atlas V's Centaur stage and GEM 63 boosters. Its first flight carried the Peregrine lunar lander, and Amazon's Project Kuiper satellites and the Dream Chaser spaceplane are planned payloads.
Primary payload of the first flight (Cert-1)
38 Vulcan launches planned to deploy most of the constellation
Planned cargo flights to the International Space Station
Boeing
NASA plans to certify Vulcan for Starliner after the final Atlas V flight (announced 28 Sep 2026); not yet flown
Replaces Delta IV Heavy
Main engines of the booster
GEM 63XL solid rocket boosters (zero, two, four or six)
Built the friction stir welding machines used on the cryogenic tanks
Joint venture of Lockheed Martin and Boeing
Blue Origin
BE-4 engine. Here: Booster: two engines, each 550,000 lbf at sea level. There: 7 on the reusable first stage of the current 7x2 version.
NASA
RL10 engine. Here: Centaur V: two RL10C-1-1A engines, 23,825 lbf each. There: ICPS: one RL10B-2 engine (24,750 lbf).
United Launch Alliance
RL10 engine. Here: Centaur V: two RL10C-1-1A engines, 23,825 lbf each. There: Common Centaur: one engine (SEC) or two (DEC); RL10A-4-2 in the 2010 guide, RL10C-1 now.
United Launch Alliance
Aluminium. Here: Booster propellant tanks; Booster tank panels and domes. There: Booster LO2 and RP tanks; Propellant feedlines and more.
Aluminium honeycomb core. Here: Payload fairing sandwich construction (refines the existing 5.4 m fairing row); Payload fairing sandwich construction. There: Booster heat shield; 5-m payload fairing and more.
graphite-epoxy composite. Here: GEM 63XL motor case. There: Helium storage bottles (x2, composite).
stainless steel. Here: Centaur V propellant tank. There: Centaur propellant tanks.
ESA
Aluminium. Here: Booster propellant tanks; Booster tank panels and domes. There: Telescope (structure and mirrors, 3 telescopes).
Aluminium honeycomb core. Here: Payload fairing sandwich construction (refines the existing 5.4 m fairing row); Payload fairing sandwich construction. There: Structure (summary).
Multilayer insulation. Here: Multilayer insulation (MLI) blankets and radiation shields. There: Instrument thermal wrap.
NASA
Aluminium. Here: Booster propellant tanks; Booster tank panels and domes. There: Mirror reflective layer; Outer shell.
graphite-epoxy composite. Here: GEM 63XL motor case. There: Frame.
Multilayer insulation. Here: Multilayer insulation (MLI) blankets and radiation shields. There: Multilayer insulation shroud.
NASA
Aluminium. Here: Booster propellant tanks; Booster tank panels and domes. There: Pressure vessel (seven large pieces, friction-stir welded); Backbone assembly (floor structure) and more.
composite. Here: 5.4-m payload fairing; 1575 PAF. There: Oxygen and nitrogen tanks (x3 oxygen, x1 nitrogen).
Multilayer insulation. Here: Multilayer insulation (MLI) blankets and radiation shields. There: Passive thermal control: multilayer insulation blankets (incl. high-temperature blankets at thrusters and nozzle) and heaters.
Pumpkin Space Systems
Aluminium. Here: Booster propellant tanks; Booster tank panels and domes. There: Structure, three major assemblies; Through-hole spacers, aluminium, 15.24 mm x 6.0 mm OD (x16) and more.
stainless steel. Here: Centaur V propellant tank. There: Chassis screws (ten per structure, M3x5mm flathead); Threaded rods, M3 stainless (x4) and more.
ESA
Aluminium. Here: Booster propellant tanks; Booster tank panels and domes. There: TPMU/DSLP housing.
Aluminium honeycomb core. Here: Payload fairing sandwich construction (refines the existing 5.4 m fairing row); Payload fairing sandwich construction. There: H-configuration inner panels (3); Outer panels without cells and more.
ULA's user guide says nothing about alloys. The aluminium alloy of the booster tanks, the grade of the Centaur V stainless steel, and the resin and fibre in the fairing and booster cases are not named. Nor are the makers of valves, batteries and avionics boxes, or the supplier of Vulcan's RL10 engines.
What is written above is built from these numbers and quotes. Each row links to the page it was taken from. Get all of it as JSON, or ask our MCP server.
| What | Value |
|---|---|
| BE-4 thrust | 2446.5 kN (550k-lbf) sea level each, two engines |
| Liftoff thrust | over 3.3M pounds maximum |
| Fairing length | 15.5 m standard or 21.3 m long |
| Booster diameter | 5.4 m |
| Upper stage engines | two RL10C engines |
| First flight (Cert-1) | 8 Jan 2024, 2:18 a.m. EST, Space Launch Complex-41; Astrobotic Peregrine to a trans-lunar orbit |
| First national security launch (USSF-106) | 12 Aug 2025, VC4S, direct to geosynchronous orbit |
| Centaur V size | 5.4 m diameter, 11.7 m long, 120,000 lb propellant capacity |
| Vehicle height | about 61.6 m (202 ft) with the standard fairing; 67.4 m (221 ft) with the long fairing |
| RL10C-1-1A thrust | 23,825 lbf (106 kN) each |
| GEM 63XL total mass and thrust | 117,700 lb (53,400 kg); maximum thrust 463,249 lbf; 864 in long |
| GEM 63XL maximum thrust | 463,249 lbf |
| GEM 63XL length | 864 in (2,195 cm); longest single-cast solid motor produced |
| SRB burn | about a minute and a half, then jettisoned |
| Launch manifest at first flight | more than 70 launches on the manifest |
Each material named in the sources: where it is used here, which other products use it, and its key numbers when its material page exists.
Used in 2 partsBooster propellant tanks · Booster tank panels and domes
Used in 2 parts5.4-m payload fairing · 1575 PAF
Used in 2 partsPayload fairing sandwich construction (refines the existing 5.4 m fairing row) · Payload fairing sandwich construction
Used in 1 partGEM 63XL motor case
Used in 1 partMultilayer insulation (MLI) blankets and radiation shields
Used in 1 partSpray-on foam insulation (SOFI)
Used in 1 partCentaur V propellant tank
The user guide names the structural material of the booster, Centaur V, fairing type and the 1575 PAF. It gives no alloys, composite systems or internal parts lists. Components, suppliers and links were added from public sources. A material is left blank where no source states it.
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| Booster propellant tanks“The Vulcan booster is made of aluminum orthogrid tanks” | aluminum (orthogrid panels)aluminium | — | — |
| Booster tank panels and domes“Brakepress-formed Orthogrid panels” | aluminum (alloy not stated)aluminium | — | — |
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| Centaur V propellant tank“Centaur V uses a pressure stabilized stainless steel tank” | stainless steel (grade not stated)stainless-steel | — | — |
| RL10C-1-1A engines (x2)Restartable hydrogen/oxygen upper-stage engines“powered by two RL10C-1-1A engines producing 23,825 pounds (106 kilo-Newtons) of thrust” | Not said | — | — |
| Centaur V LH2 and LO2 tanks with common bulkhead and aft bulkheadCryogenic propellant tanks of the stage“The Centaur upper stage is 5.4 m (17.7 ft) in diameter and 11.7 m (38.5 ft) long with a 120,000-lb propellant capacity.” | Not said | — | — |
| Centaur V LH2 feedlineCarries liquid hydrogen to the engines“Centaur Fuel (LH2) Feedline” | Not said | — | — |
| Spray-on foam insulation (SOFI)Cuts cryogen boil-off in flight“The cryogenic tanks are insulated with spray-on foam insulation (SOFI) to manage boil off of cryogens during flight.” | spray-on foam insulation (foam type not stated)sofi-spray-on-foam | — | — |
| Multilayer insulation (MLI) blankets and radiation shieldsAdded tank insulation for long coast“multilayer insulation (MLI) blankets, radiation shields and spray-on foam insulation (SOFI)” | multilayer insulation (MLI) blanketsmultilayer-insulation-mli | — | — |
| Aft equipment shelfStructural mounting for the fault-tolerant avionics“A fault-tolerant avionics system is mounted on an aft equipment shelf.” | Not said | — | — |
| Centaur V launch vehicle forward adapter (LVFA)Mounts the payload attach fitting on top of the stage“mounted to the Centaur V Launch Vehicle Forward Adapter (LVFA)” | Not said | — | — |
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| 5.4-m payload fairing“Composite 5.4m Payload” | composite (type not stated)fibre-reinforced-polymer-composite | — | — |
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| 1575 PAF“composite fiber reinforced polymer/aluminum honeycomb structure with metallic forward and aft interface rings” | composite fiber reinforced polymer / aluminum honeycombfibre-reinforced-polymer-composite | — | — |
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| GEM 63XL motors“Stretched version of Atlas V GEM 63 with 10% greater total impulse” | Not said | — | — |
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| BE-4 engines (x2)First-stage main engines, liquid oxygen and liquefied natural gas“Blue Origin BE-4 main engines, each delivering 2446.5-kN” | Not said | — | Supplier: Blue Origin |
| Booster liquefied natural gas (LNG) fuel tankHolds the methane fuel for the BE-4 engines“Booster Fuel (LNG) Tank” | Not said | — | — |
| Booster liquid oxygen (LO2) tankHolds the oxidizer; over a million pounds of LO2 and LNG in total“Booster Oxidizer (LO2) Tank” | Not said | — | — |
| Booster common bulkheadShared dome between the oxygen and natural gas tanks“spun-formed aluminum domes with a common bulkhead” | Not said | — | — |
| Booster LO2 feedlineCarries oxidizer to the engines“Booster Oxidizer (LO2) Feedline” | Not said | — | — |
| Interstage adapterJoins the booster to the Centaur V“Interstage Adapter” | Not said | — | — |
| Booster propellant utilization systemSignals depletion so the BE-4 shutdown sequence can start“The BE-4 engine shutdown sequence is initiated when depletion of booster propellants is indicated by the propellant utilization system.” | Not said | — | — |
| Friction-stir welded tank barrels and domesWelded on PAR Systems friction stir machines at ULA Decatur“designing and engineering two state-of-the-art Friction Stir Welding machines to meet the precise requirements needed for manufacturing of Vulcan’s cryogenic tanks” | Not said | — | Supplier: PAR Systems (welding machines) |
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| GEM 63XL motor caseGraphite-epoxy composite pressure case“are constructed of a graphite-epoxy composite with the throttle profile designed into the propellant grain” | graphite-epoxy composite (resin and fibre grades not stated)graphite-epoxy | — | Supplier: Northrop Grumman |
| GEM 63XL nozzleFixed exhaust nozzle of each solid motor“Solid Rocket Booster Nozzle” | Not said | — | — |
| GEM 63XL nose coneAerodynamic cap of each solid motor“Nose Cone” | Not said | — | — |
| GEM 63XL propellant grainThrottle profile is designed into the grain shape“Solid Rocket Propellant” | Not said | — | — |
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| Payload fairing sandwich construction (refines the existing 5.4 m fairing row)Two-piece bisector shell around the spacecraft“a sandwich composite structure made with a vented aluminum-honeycomb core and graphite-epoxy face sheets” | graphite-epoxy face sheets over a vented aluminium-honeycomb corealuminium-honeycomb-hexweb | — | — |
| Payload fairing separation systemDebris-free horizontal and vertical separation“The PLF separates using a debris-free horizontal and vertical separation system with spring packs and frangible joint assembly.” | Not said | — | — |
| Fairing acoustic panelsCut acoustic loads on the payload“Fairing Acoustic Panels” | Not said | — | — |
| Payload fairing access doors (up to x2) and ECS inletPayload access and conditioned air through the upper cylinder“The PLF has up to two standard access doors 180° apart” | Not said | — | — |
| Payload adapters and separation systems (1575, 2624, 4991 mm interfaces)ULA-provided adapters to the payload interface“These components are designed to adapt to the 1575-mm, 2624-mm and 4991-mm interfaces” | Not said | — | — |
| Payload fairing sandwich constructionTwo-piece bisector shell around the spacecraft; names the material left as type-not-stated in the current fairing row“a sandwich composite structure made with a vented aluminum-honeycomb core and graphite-epoxy face sheets” | graphite-epoxy face sheets over a vented aluminium-honeycomb corealuminium-honeycomb-hexweb | — | — |
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| Aft Bulkhead Carrier (ABC)Rideshare carrier at the aft end of the Centaur“The Aft Bulkhead Carrier (ABC) interfaces at the aft end of the Centaur upper stage” | Not said | — | — |
| EELV secondary payload adapter (ESPA ring and ESPA Grande)Ring that carries several small satellites around the primary payload“The Secondary Payload Adapter (ESPA Ring) is located between the upper stage and the primary payload” | Not said | — | — |
| Multi-Launch System: multi-launch adapter, aft payload attach fitting, internal canisterLoad-bearing canister that encloses an aft payload under a forward one“the Multi-Payload Canister System is a load-bearing separating canister that can be utilized to enclose an aft small satellite” | Not said | — | — |
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| Avionics systemGuidance, flight control and sequencing in booster and Centaur phases“controlled by an avionics system that provides guidance, flight control and vehicle sequencing functions during the booster and Centaur phases of flight” | Not said | — | — |
Aluminum alloy, stainless grade and fairing composite not stated; GEM 63XL case and propellant materials not stated in this guide; BE-4 and RL10 internals not covered; first flight date not in the guide. More detail: The 2023 user guide has no vehicle-description chapter, so booster and Centaur V internals come from ULA fact sheets and the USSF-106 page. Not published in the pages read: aluminium alloy of the booster tanks, stainless grade of Centaur V, resin and fibre of the fairing and GEM 63XL case, RL10C-1-1A internals, and the makers of valves, batteries, avionics boxes and the Centaur V forward adapter. The RL10 maker for Vulcan is not named in these ULA pages (ULA's Atlas V page names L3Harris for RL10C-1). The fairing sandwich statement (graphite-epoxy faces over vented aluminium honeycomb) resolves the 'composite (type not stated)' row in the current entry, and the GEM 63XL case statement resolves the missing SRB case material. More detail: The 2023 user guide has no vehicle-description chapter, so booster and Centaur V internals come from ULA fact sheets and the USSF-106 page. Not published in the pages read: aluminium alloy of the booster tanks, stainless grade of Centaur V, resin and fibre of the fairing and GEM 63XL case, RL10C-1-1A internals, and the makers of valves, batteries, avionics boxes and the Centaur V forward adapter. The RL10 maker for Vulcan is not named in these ULA pages (ULA's Atlas V page names L3Harris for RL10C-1). The fairing sandwich statement (graphite-epoxy faces over vented aluminium honeycomb) resolves the 'composite (type not stated)' row in the current entry, and the GEM 63XL case statement resolves the missing SRB case material.
Collected from public pages and documents, checked 4 Nov 2026.
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