Thrust chamber and nozzle
- Combustion chamber
- Divergent nozzle (SWAN sandwich nozzle)
- Nozzle structural reinforcements
- Nozzle steering (gimbal) system
Illustration
ArianeGroup
Vulcain 2.1 engine
Gas-generator LOX/LH2 engine for the Ariane 6 core stage; sources state a laser-welded sheet-metal nozzle built by GKN Aerospace and a 3D-printed gas generator whose injection head is a nickel-based alloy. Few other materials are published.
Product ID
arianegroup-vulcain-2-1 - Height
- 3.7 m
- Diameter
- 2.5 m
- Mass
- About 2 tonnes
- Vacuum thrust
- More than 1370 kN
In short
Gas-generator LOX/LH2 engine for the Ariane 6 core stage; sources state a laser-welded sheet-metal nozzle built by GKN Aerospace and a 3D-printed gas generator whose injection head is a nickel-based alloy. Few other materials are published.
Application
Vulcain 2.1 is the single engine of the Ariane 6 core stage. It burns for about eight minutes to lift the launcher away from Earth before the Vinci upper stage takes over. Its laser-welded nozzle and 3D-printed gas generator were introduced to simplify production compared with the Ariane 5 Vulcain 2.
Photos
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How it is built
Gas generator
- Gas generator
- Gas generator injection head
- Oxygen heater for tank pressurization
Turbopumps
- Liquid hydrogen turbopump
- Liquid oxygen turbopump (Mk2)
- Liquid oxygen turbopump Dynamic Seal Package
- Liquid oxygen turbopump Active Balancing System
- Turbine assemblies
Ignition, valves and pressurisation
- Combustion chamber ignition system (ground-based)
- Gas generator igniter and turbine pump starter
- Hot gas valve (electrically operated)
- Valves and pressure regulators
- Turbopumps5
- Thrust chamber and nozzle4
- Ignition, valves and pressurisation4
- Gas generator3
What it is made of
- nickel-based alloy (grade not stated)
Used in Gas generator injection head.
How it connects to other things
Used in
Builds on
-
Vulcain engine (Ariane 5)
upgraded version of the Ariane 5 main-stage engine
-
Vulcain 2 engine
version of Vulcain 2 adapted for the Ariane 6 main stage
Made or supplied by
-
ArianeGroup
developer of the engine, with European partners, for ESA
-
GKN Aerospace
SWAN nozzle, built at Trollhattan, Sweden
1 more detail
turbine assemblies for the turbopumps
-
Avio
liquid oxygen turbopump
-
ArianeGroup France (Vernon)
liquid oxygen turbopump responsibility moving here from Avio
-
Safran (Turin site, former Microtecnica)
valves and pressure regulators
What we do not know
No alloys for the nozzle sheets, chamber liner or jacket, injector, turbopump rotors, bearings, seals, valves or ducts. No standards.
The detailed data
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.
Features
- Upgraded version of the Ariane 5 Vulcain engine
- 3D-printed gas generator, simplified divergent nozzle and electrically operated hot gas valve
- Nozzle built by laser-welding two large sheets of metal with cooling channels
- Nozzle part count cut from about 1000 parts to 100
- Combustion chamber ignition system moved from the engine to the launch pad
- Nozzle is tilted during flight to steer the rocket
- ArianeGroup says 3D printing cut the manufacturing cycle of the gas generator by half
- Liquid oxygen turbopump is common to Ariane 5 and Ariane 6
Specifications
| What | Value |
|---|---|
| Vacuum thrust | More than 1370 kN |
| Vacuum thrust (eoPortal) | 1,371 kN |
| Specific impulse (vacuum) | 432 s |
| Chamber pressure | 118.8 bar |
| Mixture ratio (oxidizer to fuel) | 6.03 |
| Cycle | Gas generator, two independent turbopumps |
| Propellants | Liquid oxygen and liquid hydrogen |
| Propellant flow and burn time | Over 327 kg/s for 468 s |
| Height | 3.7 m |
| Diameter | 2.5 m |
| Mass | About 2 tonnes |
| Nozzle diameter (SWAN nozzle) | 2.5 m |
| Engines per vehicle | One, on the Ariane 6 main (core) stage |
| First hot-fire test of the Ariane 6 version | DLR P5 test facility, Lampoldshausen, reported 23 January 2018 |
| Qualification | Completed |
| First flight | Ariane 6 maiden launch, 9 July 2024 |
Materials in detail
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.
-
nickel-based alloy (grade not stated)
nickel-based-alloyUsed in 1 partGas generator injection head
Also in 2 other productsMaterial page coming soon
Every part we have
Only the gas generator injection head has a stated material (a nickel-based alloy, from a French CETIM customer sheet). The nozzle is described as laser-welded sheet metal with no alloy named. Chamber, turbopumps, igniters and valves are listed from ESA, ArianeGroup, Avio, GKN and trade sources with no material stated.
Material IDs
nickel-based-alloy
Thrust chamber and nozzle4
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| Combustion chamber“Two turbopumps inject hydrogen and oxygen into the combustion chamber.” | Not said | — | — |
| Divergent nozzle (SWAN sandwich nozzle)“built by laser-welding two large sheets of metal together” | Not said | — | — |
| Nozzle structural reinforcements“additively manufactured structural reinforcements” | Not said | — | — |
| Nozzle steering (gimbal) system“Its nozzle is rapidly tilted and turned during a launch to keep the rocket flying upright” | Not said | — | — |
Gas generator3
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| Gas generator“a gas generator built using 3D printing, a simplified divergent nozzle, and an oxygen heater for tank pressurization” | Not said | — | — |
| Gas generator injection head“la conformité de cette pièce en alliage à base de nickel” | nickel-based alloy (grade not stated)nickel-based-alloy | — | — |
| Oxygen heater for tank pressurization“Additional 3D printed components include the gas generator and the Oxygen heater for tank pressurization” | Not said | — | — |
Turbopumps5
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| Liquid hydrogen turbopump“Two turbopumps inject hydrogen and oxygen into the combustion chamber.” | Not said | — | — |
| Liquid oxygen turbopump (Mk2)“the Mk2 turbopump features a host of improvements in hydraulics, balance, sealing, and turbine performance” | Not said | — | Avio |
| Liquid oxygen turbopump Dynamic Seal Package“In particular, Avio improved the Dynamic Seal Package (DSP)” | Not said | — | Avio |
| Liquid oxygen turbopump Active Balancing System“the Active Balancing System (ABS), which compensates for the axial forces generated by the turbine” | Not said | — | Avio |
| Turbine assemblies“These turbine assemblies will be manufactured at GKN Aerospace” | Not said | — | GKN Aerospace |
Ignition, valves and pressurisation4
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| Combustion chamber ignition system (ground-based)“the combustion chamber ignition system has been moved from the engine to the launch pad” | Not said | — | — |
| Gas generator igniter and turbine pump starter“crucial components like a Thrust Chamber Igniter (TCI), Gas Generator Igniter (GGI) and a Turbine Pump Starter (TPS)” | Not said | — | — |
| Hot gas valve (electrically operated)“a new electrically-operated hot gas valve” | Not said | — | — |
| Valves and pressure regulators“In Turin, Italy, the former Microtecnica site now owned by Safran produces valves and pressure regulators” | Not said | — | Safran, Turin |
What the sources leave out
No alloys for the nozzle sheets, chamber liner or jacket, injector, turbopump rotors, bearings, seals, valves or ducts. No standards.
Where this comes from
14 pages from 9 websites
- esa.int/Enabling_Support/Space_Transportation/Ariane/The_engines_of_Ariane_6
- directory.eoportal.org/other-space-activities/ariane6
- iafastro.directory/iac/archive/browse/IAC-16/C4/1/34554
- ariane.group/en/space/propulsion
- esa.int/ESA_Multimedia/Images/2017/10/Vulcain_2.1
- adsgroup.org.uk/knowledge/industry-member-news/gkn-delivers-advanced-ariane-6-nozzle-
- ariane.group/en/news/successful-first-test
- esa.int/Enabling_Support/Space_Transportation/Ariane/Ariane_6_what_s_it_made_
- imeche.org/news/news-article/3d-printing-slashes-manufacturing-time-for-european
- avio.com/cryogenic-turbopumps
- adsgroup.org.uk/knowledge/industry-member-news/gkn-aerospace-wins-ariane-6-rocket-eng
- cetim.fr/content/download/170551/fichier/Fiche%20Ref%20-%20ArianeGroup%20(FR).
- 3dprintingindustry.com/news/vulcain-2-1-test-fired-3d-printed-rocket-engine-parts-lift-off-2
- esa.int/Enabling_Support/Space_Transportation/Ariane/Ariane_6_made_in_Italy
More space products
Collected from public pages and documents, checked 4 Nov 2026.
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