Prometheus (rocket engine)


The Prometheus rocket engine is an ongoing European Space Agency (ESA) development effort begun in 2017 to create a reusable methane-fueled rocket engine for use on the Themis reusable rocket demonstrator and Ariane Next, the successor to Ariane 6, and possibly a version of Ariane 6 itself.[1][2]

Prometheus is a backronym standing for "Precursor Reusable Oxygen Methane cost Effective propulsion System", and for the Titan Prometheus, from Greek mythology, creator of humanity, and god of fire, known for giving fire to humanity in defiance of the gods.

By 2020, the development program was funded, and is being developed for the ESA by Ariane Group.[3]

The engine is aimed to be reusable with substantially lower costs than traditional engines manufactured in Europe. The cost goal is to manufacture the Prometheus engine at one-tenth the cost of the Ariane 5's first-stage engine.[4][3]

General characteristics

The engine is planned to have the following features:

  • Methane–oxygen propellant.
  • Extensive use of metal 3D printing (up to 50% of the engine).[3]
  • Open gas-generator cycle.[5]
  • 980 kN of thrust (~100 tonnes), variable from 30% to 110% thrust.[5]
  • 100 bar (10,000 kPa) chamber pressure.[5]
  • 360 s specific impulse (Isp).[citation needed]
  • Reusable 3 to 5 times.[citation needed]
  • Around 1 million euros production cost.[5]


The European Space Agency (ESA) began funding Prometheus engine development in June 2017 with €85 million provided through the Future Launchers Preparatory Programme, 63% of which coming from France.[1]

By June 2017, Patrick Bonguet, lead of the Ariane 6 launch vehicle program at Arianespace, indicated that it was possible the Prometheus engine could find a use on a future version of the expendable Ariane 6 launcher. In this scenario, a "streamlined version of Vulcain rocket engine called Vulcain 2.1 would have the same performance as Vulcain 2". The expendable Ariane 6 was then expected to make an initial launch in 2020.[4]

By June 2020, the ESA was onboard with this plan and had agreed to completely fund the development of the Prometheus precursor engine to bring the "engine design to a technical maturity suitable for industry". The objective of the overall program as stated in June 2020 was to utilize Prometheus technology to eventually "lower the cost of production by a factor of ten of the current main stage Ariane 5 Vulcain 2 engine".[3]

See also


  1. ^ a b Henry, Caleb (5 October 2017). "France's Prometheus reusable engine becomes ESA project, gets funding boost". SpaceNews. Retrieved 9 January 2018.
  2. ^ Patureau de Mirand, Antoine (July 2019). Ariane Next, a vision for a reusable cost efficient European rocket (PDF). 8th European Conference for Aeronautics and Space Sciences. doi:10.13009/EUCASS2019-949. Retrieved 18 August 2021.
  3. ^ a b c d "ESA moves ahead on low-cost reusable rocket engine". European Space Agency. 4 June 2020. Retrieved 4 June 2020.
  4. ^ a b Henry, Caleb (8 January 2018). "France, Germany studying reusability with a subscale flyback booster". SpaceNews. Retrieved 9 January 2018.
  5. ^ a b c d Iannetti, A.; Girard, N.; Tchou-kien, D.; Bonhomme, C.; Ravier, N.; Edeline, E. (July 2017). PROMETHEUS, A LOX/LCH4 REUSABLE ROCKET ENGINE (PDF). 7th European Conference for Aeronautics and Space Sciences. doi:10.13009/EUCASS2017-537. Retrieved 2 March 2019.

External links

  • ESA Prometheus website