Vinci (rocket engine)

The Vinci rocket engine is a {{Convert|180|kN|adj=on}} restartable, upper stage cryogenic engine using the expander cycle and fed with liquid hydrogen and liquid oxygen. Its biggest improvement over the HM7B engine used on the Ariane 5 is the capability of restarting four times. It is the first European expander cycle engine, removing the need for a gas generator to drive the fuel and oxidizer pumps. The expander cycle was found to be the most promising option to achieve higher reliability, higher performance, multiple ignition capability and low recurring cost.

The engine features a high-performance hydrogen turbopump, an optimized combustion chamber cooling circuit, and cutting-edge manufacturing processes, including powder metallurgy impellers and high-speed cooling channel milling. The combustion chamber body incorporates a smooth-wall design, utilizing the same technology as the HM7B and Vulcain engines, except significantly lengthened.{{Cite journal |last=Alliot |first=P. |last2=Delange |first2=J.-F. |last3=Korver |first3=V. De |last4=Sannino |first4=J.-M. |last5=Lekeux |first5=A. |last6=Vieille |first6=B. |date=2019 |title=VINCI, the European reference for Ariane 6 upper stage cryogenic propulsive system |url=https://www.eucass-proceedings.eu/articles/eucass/abs/2019/01/eucass2019_481/eucass2019_481.html |journal=Progress in Propulsion Physics – Volume 11 |language=en |publisher=EDP Sciences |volume=11 |pages=481–494 |doi=10.1051/eucass/201911481 |isbn=978-5-94588-228-7|doi-access=free }}

To enable re-ignition, the Vinci engine is paired with an auxiliary propulsion unit (APU), which performs two important functions. First, the APU can heat up small amounts of propellant inside a 3D-printed gas generator and that gas is injected back into the tanks to re-pressurize them. Secondly, the APU can produce a low level of thrust, to either settle floating propellant in the tanks before re-ignition of the Vinci engine or to make fine orbital adjustments (similar to a thruster). Using the APU reduces overall weight, by eliminating the need to carry a helium tank (the traditional method of re-pressuring propellant tanks).{{Cite web |last=Clark |first=Stephen |date=2024-07-10 |title=Europe’s first Ariane 6 flight achieved most of its goals, but ended prematurely |url=https://arstechnica.com/space/2024/07/europes-first-ariane-6-flight-achieved-most-of-its-goals-but-ended-prematurely/ |access-date=2024-07-11 |website=Ars Technica |language=en-us}}

The preliminary design of Vinci began under the Ariane 5+ program managed by CNES, delegated by ESA. Between 2006 and 2008, engineering and testing were conducted under ESA's Future Launcher Preparatory Program (FLPP). From 2009 to 2014, Vinci was developed as the upper-stage propulsion system for the next evolution of the upgraded Ariane 5ME (Midlife Evolution) launcher by the space engines division of Safran Aircraft Engines. However, funding for the Ariane 5ME programme was cut in 2014 in favour of developing Ariane 6.

By the end of 2014, Vinci successfully completed its critical design review (CDR), following successful CDRs for its major subsystems (combustion chamber, fuel and oxygen turbopumps) throughout the latter half of the year.

In July 2017, the newly-formed Ariane Group, a joint venture between Airbus and Safran, reported that the first flight models of the combustion chamber had entered production.{{cite web|url=https://www.ariane.group/en/news/airbus-safran-launchers-starts-production-of-the-first-flight-model-for-the-vinci-engine-combustion-chamber-intended-for-the-ariane-6-upper-stage/|access-date=28 July 2017 |title=ArianeGroup starts production of the first flight model for the VINCI engine combustion chamber intended for the Ariane 6 upper stage}}

In October 2018, Ariane Group announced that qualification tests had been completed, proving the engine and upper stage were capable of operating for at least 900 seconds and four burns. The company said that during tests to push the engine beyond its operational requirements, it had successfully fired the engine 20 times during a single test of 300 seconds and, in another test, had fired the engine for a total duration of 1,569 seconds.{{Cite press release |last= |date=22 October 2018 |title=Ariane 6 Vinci engine: successful qualification tests |url=https://www.ariane.group/en/news/ariane-6-vinci-engine-successful-qualification-tests/ |access-date=2024-07-11 |website=ArianeGroup |language=en-US}}

The first flight of the Ariane 6 rocket with Vinci took place on 9 July 2024. The engine worked normally during the initial launch and a brief second burn. However, it failed to restart for a third burn due to an anomaly with its auxiliary propulsion unit,{{Cite tweet |number=1810791073272492464 |user=planet4589 |title=Anomaly on the Ariane 6 mission: the APU did not properly restart in the second coast phase. The APU operation affects the orbital parameters, and these did not change as expected. Unclear if the deorbit burn can be performed. |first=Jonathan |last=McDowell |author-link=Jonathan McDowell |date=9 July 2024}}{{Cite news |last=Amos |first=Jonathan |date=2024-07-10 |title=Europe's Ariane-6 rocket blasts off on maiden flight |url=https://www.bbc.com/news/articles/c19km33k1mpo |access-date=2024-07-10 |work=BBC |language=en-GB}} precluding a deorbit burn.{{Cite tweet |number=1810812852292165927 |user=AndrewParsonson |title=Ending off the press conference, Martin Sion confirmed that the upper stage can not be deorbited. Considering ESA's recent focus on its Zero Debris charter, this isn't a great look. Sion was also surprisingly flippant in his response to how long the stage would remain in orbit. |first=Andrew |last=Parsonson |date=10 July 2024}}

• Spacecraft propulsion
• M10 (rocket engine)

• RL10
• RL60
• HM7B
• YF-75D
• RD-0146
• LE-5B-2
• CE-20

{{reflist}}

• [http://www.esa.int/Our_Activities/Launchers/Vinci_engine_hot-firing_test_a_success ESA news 2005-05-20: Vinci engine hot-firing test a success]
• [http://www.esa.int/Our_Activities/Launchers/Testing_the_new_Vinci_engine ESA news 2005-06-14: Testing the new Vinci engine]
• [http://www.esa.int/Our_Activities/Launchers/Thumbs_up_for_60-second_firing ESA news 2005-07-29: Thumbs up for 60-second firing]
• [http://www.esa.int/Our_Activities/Launchers/Second_Vinci_engine_ready_for_testing ESA news 2005-11-07: Second Vinci engine ready for testing]

{{Rocket engines}}

{{Ariane}}

{{Snecma aeroengines}}

{{DEFAULTSORT:Vinci}}

Category:Rocket engines using hydrogen propellant

Category:Rocket engines using the expander cycle