Country of origin France Last flight 18 December 2009 Manufacturer Snecma | First flight 04 June 1996 Designer Snecma Application Main stage engine | |
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Vulcain is a family of European first stage rocket engines for the Ariane 5. Its development began in 1988 and the first flight was completed in 1996. The updated version of the engine – Vulcain 2 was first successfully flown in 2005. Both members of the family use liquid oxygen/liquid hydrogen cryogenic fuel. As of 2012 no new version of the engine is in development.
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History
The development of Vulcain, carried out by a European partnership, began in 1988 with the Ariane 5 rocket program. It first flew in 1996 powering the ill-fated flight 501 without being the cause of the disaster, and had its first successful flight in 1997 (flight 502). In 2002 the upgraded Vulcain 2 with 20% more thrust first flew on flight 517, although a problem with the engine turned the flight into a failure. The cause was due to flight loads being much higher than expected, as the inquiry board concluded. Subsequently the nozzle was redesigned to include mechanical reinforcement of the structure and improvement of the thermal situation of the tube wall through enhancing hydrogen coolant flow as well as applying a thermal barrier coating to the flame-facing side of the coolant tubes. The first successful flight of the (partially redesigned) Vulcain 2 occurred in 2005 on flight 521.
Future development
Although different upgrades to the engine have been proposed, there is no current program to develop an uprated version of the engine. If there will ever be one, it is likely that the new engine would be introduced after the "PA batch" of 30 Ariane 5 ECAs ordered on 10 May 2004 will be expended.
On 17 June 2007 Volvo Aero announced that in spring of 2008 it expected to hot-fire test a Vulcain 2 nozzle manufactured with a new "sandwich" technology.
Overview
The Vulcain engines are gas-generator cycle cryogenic rocket engines fed with liquid oxygen and liquid hydrogen. They feature regenerative cooling through a tube wall design, and the Vulcain 2 introduced a particular film cooling for the lower part of the nozzle, where exhaust gas from the turbine is re-injected in the engine They power the first stage of the Ariane 5 launcher, the EPC (Étage Principal Cryotechnique, main cryogenic stage) and provide 8% of the total lift-off thrust (the rest being provided by the two solid rocket boosters). The engine operating time is 600 s in both configurations. 3 m tall and 1.76 m in diameter, the engine weighs 1686 kg and provides 137 t of thrust in its latest version. The oxygen turbopump rotates at 13600 rpm with a power of 3 MW while the hydrogen turbopump rotates at 34000 rpm with 12 MW of power. The total mass flow rate is 235 kg/s, of which 41.2 kg/s are of hydrogen.
Contractors
The main contractor for the Vulcain engines is Snecma Moteurs (France), which also provides the liquid hydrogen turbopump. The liquid oxygen turbopump is the responsibility of Avio (Italy), and the gas turbines that power the turbopumps and the nozzle are developed by GKN (Formerly Volvo) (Sweden).