Ariane 6
Ariane 6 is a European expendable launch system developed for the European Space Agency and French Space Agency and manufactured by a consortium of European companies, led by the prime contractor ArianeGroup. As part of the Ariane rocket family, it is operated by Arianespace, replacing the Ariane 5. The project's primary contributors were France, Germany and Italy, with the remaining work distributed among ten other participating countries.
This two-stage rocket utilizes liquid hydrogen and liquid oxygen engines. The first stage features an upgraded Vulcain engine from Ariane 5, while the second uses the Vinci engine, designed specifically for this rocket. The Ariane 62 variant uses two P120C solid rocket boosters, while Ariane 64 uses four. The P120C booster is shared with Europe's other launch vehicle, and is an improved version of the P80 used on the original Vega.
Selected in December 2014 over an all-solid-fuel alternative, Ariane 6 was initially planned for a 2020 debut. However, the program faced delays, with the first launch eventually taking place on 9 July 2024. While the rocket successfully launched, the mission experienced a partial failure when the upper stage malfunctioned and was not able to complete its final deorbit burn. The second launch was therefore postponed to 6 March 2025, successfully delivering its first commercial payload to orbit, the CSO-3 reconnaissance satellite.
Ariane 6 was designed to halve launch costs and increase annual launch capacity from seven to eleven missions compared to its predecessor., neither target has been achieved. The program has been subject to criticism over high costs and lack of reusability versus competitors' rockets, such as SpaceX's Falcon 9. European officials defend the program, saying it provides crucial independent space access for its member states.
Description
Two variants of Ariane 6 are offered:- Ariane 62, with two P120C solid boosters, weighs around at liftoff and is mainly for government and scientific missions. It can launch up to into geosynchronous transfer orbit and into low Earth orbit. The first launch in 2024 used this variant;
- Ariane 64, with four P120C boosters, has a liftoff weight of around and is intended for commercial dual-satellite launches of up to into GTO and into LEO. Like Ariane 5, it will be able to launch two geosynchronous satellites together.
First stage
The first stage of Ariane 6 is called the Lower Liquid Propulsion Module. It is powered by a single Vulcain 2.1 engine fueled by liquid hydrogen with liquid oxygen. The LLPM is in diameter and contains approximately of propellant.Boosters
Additional thrust for the first stage will be provided by either two or four P120C model solid rocket boosters, known within Ariane 6 nomenclature as Equipped Solid Rockets. Each booster contains approximately of propellant and delivers up to of thrust. The P120C engine is also used in the first stage of the upgraded Vega C launcher. By sharing motors, production volumes can be increased, lowering production costs. The first full-scale test of the ESR occurred at Kourou, French Guiana, on 16 July 2018, and the test completed successfully with thrust reaching in vacuum.Second stage
The second stage of Ariane 6 is called the Upper Liquid Propulsion Module. It shares the same diameter as the LLPM and is also fueled by LH2 and LOX. It is powered by the Vinci engine, which delivers of thrust, burns for up to 900 seconds and is capable of up to five restarts. The ULPM carries about of propellant.ASTRIS
The Ariane Smart Transfer and Release In-orbit Ship was originally conceived as a kick stage to enable higher orbits for specific payloads. However, it was decided during the November 2025 ESA Council Meeting to evolve ASTRIS into an orbital transfer vehicle.Designed specifically for the Ariane 6 rocket, it will be an optional add-on to the upper stage and interface directly with the payload. ASTRIS features a steerable main engine that can reignite multiple times to perform orbital changes, and it has six thrusters to perform manoeuvres such as reorienting itself in space along its trajectory.
This will simplify many missions by off-loading some of the required built-in propulsion capabilities of payloads to move themselves to their final orbital position. For example, Astris could enable deep space exploration for ridesharing payloads with destinations such as asteroids, the Moon and Mars; insert a payload directly into geostationary orbit; or augment Ariane 6’s ability to deploy multiple payloads such as a constellation into separate low Earth orbits on a single launch.
ASTRIS can also deliver satellites for a small constellation directly into their operational orbits, allowing for the satellites to be smaller and cheaper to build. Ground qualification is expected by the end of 2028, with the inaugural flight in 2029.
Fairing
The payload fairing, constructed by Beyond Gravity from a carbon fibre-polymer composite, is designed as a nose cone that splits vertically into two halves at the top of the Ariane 6 rocket. It is available in two sizes: a long version and a short version, both with a diameter of. The interior of the cylindrical payload compartment is in diameter and the long variant measures in height, or when including the conical portion of the fairing.Block 2
A more powerful "Block 2" version of Ariane 6 is slated to enter service in 2026, featuring enlarged P160C solid rocket boosters and an enhanced Vinci engine in the upper stage with increased thrust of. These improvements will expand the rocket’s flight envelope and significantly boost its payload capacity, with an expected gain of to low Earth orbit on the Ariane 64.Development of the P160C boosters began in 2022. The upgraded boosters are extended by to carry an additional of propellant. Notably, 16 of the 18 planned Kuiper launches on Ariane 6 will incorporate this upgraded booster. The first P160C booster casing was built in June 2024, with fueling and static fire tests anticipated in 2025.
To support these more powerful rockets, CNES is assisting in modifying the existing launch pad. The first Ariane 6 launch with the P160C is planned for Q2 2026 in the Ariane 64 configuration.
Block 3
An additional Block 3 upgrade is being discussed by the European Space Agency, ArianeGroup and CNES. Increased performance will primarily be achieved via an upgraded upper stage.PHOEBUS is a program to replace the metal tanks currently used with lighter linerless CFRP tanks for Ariane 6. This offers the possibility of saving several tonnes of mass, allowing for more payload mass. A full scale liquid oxygen model is being readied for tests in early 2026, while tests with liquid hydrogen will start in April 2026.
The impetus for the upgrade is a number of upcoming lunar missions, including the European Argonaut logistics lunar lander project. A decision is expected during the November 2025 European ministerial meeting.
History
Ariane 6 was conceived in the early 2010s to be a replacement launch vehicle for Ariane 5, and a number of concepts and high-level designs were suggested and proposed during 2012–2015. Development funding from several European governments was secured by early 2016, and contracts were signed to begin detailed design and the build of test articles. In 2019, the maiden orbital flight had been planned for 2020, however by May 2020, the planned initial launch date was delayed into 2021. In October 2020, the European Space Agency formally requested an additional in funding from the countries sponsoring the project to complete development of the rocket and get the vehicle to its first test flight, which had slipped to the second quarter of 2022. By June 2021, the date had delayed to late 2022. In June 2022, a delay was announced to "some time in 2023" and by October 2022, ESA clarified that the first launch would be no earlier than the fourth quarter of 2023, while providing no public reason for the delay. In August 2023, ESA announced that the date for the first launch had slipped again to 2024.Concept and early development: 2010–2015
Following detailed definition studies in 2012, ESA announced in July 2013 the selection of the "PPH" configuration for Ariane 6. It would be capable of launching up to to Geostationary transfer orbit, with a first flight projected to be as early as 2021–2022. Development was projected to cost €4 billion. A 2014 study concluded that development cost could be reduced to about €3 billion by limiting contractors to five countries.While Ariane 5 typically launches one large and one medium satellite at a time, the PPH proposal for Ariane 6 was intended for single payloads, with an early 2014 price estimate of approximately US$95 million per launch. The SpaceX Falcon 9 and the Chinese Long March 3B both launch smaller payloads but at lower prices, approximately $57 million and $72 million respectively as of early 2014, making the Falcon 9 launch of a midsize satellite competitive with the cost of the lower slot of a dual payload Ariane 5. For lightweight all-electric satellites, Arianespace intended to use the restartable Vinci engine to deliver the satellites closer to their operational orbit than the Falcon 9 could, thus reducing the time required to transfer to geostationary orbit by several months.
Ariane 6.1 and Ariane 6.2 proposals
In June 2014, Airbus and Safran surprised ESA by announcing a counter proposal for the Ariane 6 project: a 50/50 joint venture to develop the rocket, which would also involve buying out the French government's CNES interest in Arianespace.This proposed launch system would come in two variants, Ariane 6.1 and Ariane 6.2. While both would use a cryogenic main stage powered by a Vulcain 2 engine and two P145 solid boosters, Ariane 6.1 would feature a cryogenic upper stage powered by the Vinci engine and boost up to to GTO, while Ariane 6.2 would use a lower-cost hypergolic upper stage powered by the Aestus engine. Ariane 6.1 would have the ability to launch two electrically powered satellites at once, while Ariane 6.2 would be focused on launching government payloads.
French newspaper La Tribune questioned whether Airbus Defence and Space could deliver on the promised costs for their Ariane 6 proposal, and whether Airbus and Safran Group could be trusted when they were found to be responsible for a failure of Ariane 5 flight 517 in 2002 and a more recent 2013 failure of the M51 ballistic missile. The companies were also criticised for being unwilling to incur development risks, and asking for higher initial funding than originally planned instead of. Estimated launch prices of for Ariane 6.1 and for Ariane 6.2 did not compare favorably to SpaceX offerings. During the meeting of EU ministers in Geneva on 7 June 2014, these prices were deemed too high and no agreement with manufacturers was reached.