ABOUT VULCAIN 2
The Vulcain 2 is the cryogenic main engine of the Ariane 5 core stage, developed by ArianeGroup (formerly Snecma/SEP). It uses a gas-generator cycle burning liquid hydrogen and liquid oxygen, producing 1,359 kN of vacuum thrust. The Vulcain 2 powered over 100 successful Ariane 5 flights and represented Europe’s premier large cryogenic engine technology.
Image: ESA
PERFORMANCE
| Thrust (Sea Level) | 960 kN (215,800 lbf) kN |
| Thrust (Vacuum) | 1,359 kN (305,500 lbf) kN |
| ISP (Sea Level) | 318 s s |
| ISP (Vacuum) | 434 s s |
| Chamber Pressure | 11.5 MPa (1,668 psi) bar |
| Mass | 2 kg |
| Thrust-to-Weight | 68 |
| Throttle Range | Not throttleable |
| Restart Capable | No |
THRUST CONVERSIONS (VACUUM)
| Kilonewtons | 1.0 kN |
| Pounds-force | 225 lbf |
ENGINE CYCLE
Gas Generator
A gas generator cycle taps off a small portion of propellants to drive turbopumps via a separate combustion chamber. The turbine exhaust is dumped overboard, making it less efficient but simpler and more reliable. Used by the Merlin, F-1, and RS-27.
PROPULSION
| Propellant | Liquid Hydrogen (LH₂) |
| Oxidizer | LOX |
| Engine Cycle | Gas Generator |
| Mixture Ratio | 6.1:1 |
| Flow Rate | ~320 kg/s kg/s |
PHYSICAL
| Dimensions | 1.76 m diameter × 3.0 m length |
| Combustion Chambers | 1 |
| Nozzle Expansion Ratio | 58.5:1:1 |
GENERAL
| Manufacturer | ArianeGroup |
| Country | France / Europe |
| Status | Retired (with Ariane 5) |
| First Flight | April 16, 2026 |
VARIANTS (3)
- Vulcain
- Vulcain 2
- Vulcain 2.1
VEHICLES USING VULCAIN 2 (2)
- Ariane 5 ECA
- Ariane 6
ENGINE LINEAGE
Vulcain→Vulcain 2→Vulcain 2.1 (Ariane 6)
⚖ PROPELLANTS
🏢 MANUFACTURER
