The Vulcain 2.1 from Arianespace is a Satellite Launch Vehicle Cryogenic Engine that produces a vacuum thrust of 1371 kN and has a specific impulse of 432 sec. This main stage engine has a combustion pressure of 118.8 bar and uses a combination of liquid hydrogen (LH2) and liquid oxygen (LOX) as the propellant. The Vulcain 2.1 incorporates recent technological developments such as 3D printing, SWAN nozzle, etc., and draws on the proven reliability of the Vulcain engine. It measures 3.6 m (height) and has a nozzle diameter of 2.1 m. This engine powers the Ariane 6 cryogenic main stage and is being developed by ArianeGroup in cooperation with its European partners on behalf of the European Space Agency (ESA).
