Ariane 5 () is a retired European heavy-lift space launch vehicle operated by Arianespace for the European Space Agency (ESA). It was launched from the Guiana Space Centre (CSG) in French Guiana. It was used to deliver payloads into geostationary transfer orbit (GTO), low Earth orbit (LEO) or further into space. The launch vehicle had a streak of 82 consecutive successful launches between 9 April 2003 and 12 December 2017. In development since 2014, Ariane 6, a direct successor system was first launched in 2024.
The system was designed as an expendable launch vehicle by the Centre National d'Études Spatiales (CNES), the French government's space agency, in cooperation with various European partners. Despite not being a direct derivative of its predecessor launch vehicle program, it was classified as part of the Ariane rocket family. Aérospatiale, and later ArianeGroup, was the prime contractor for the manufacturing of the vehicles, leading a multi-country consortium of other European contractors. Ariane 5 was originally intended to launch the Hermes spacecraft, and thus it was rated for human space launches.
Since its first launch, Ariane 5 was refined in successive versions: "G", "G+", "GS", "ECA", and finally, "ES". The system had a commonly used dual-launch capability, where up to two large geostationary belt communication satellites can be mounted using a SYLDA (Système de Lancement Double Ariane, meaning "Ariane Double-Launch System") carrier system. Up to three, somewhat smaller, main satellites are possible depending on size using a SPELTRA (Structure Porteuse Externe Lancement Triple Ariane, which translates to "Ariane Triple-Launch External Carrier Structure"). Up to eight secondary payloads, usually small experiment packages or minisatellites, could be carried with an ASAP (Ariane Structure for Auxiliary Payloads) platform.
Following the launch of 15 August 2020, Arianespace signed the contracts for the last eight Ariane 5 launches, before it was succeeded by the new Ariane 6 launcher, according to Daniel Neuenschwander, director of space transportation at the ESA. Ariane 5 flew its final mission on 5 July 2023.
Vehicle description Cryogenic main stage
Ariane 5's cryogenic H173 main stage (H158 for Ariane 5G, G+, and GS) was called the EPC (Étage Principal Cryotechnique — Cryotechnic Main Stage). It consisted of a diameter by high tank with two compartments, one for liquid oxygen and one for liquid hydrogen, and a Vulcain 2 (Vulcain 1 for Ariane 5G, G+, and GS) engine at the base with a vacuum thrust of . The H173 EPC weighed about , including of propellant. After the main cryogenic stage runs out of fuel, it re-entered the atmosphere for an ocean splashdown.
Solid boosters Attached to the sides were two P241 (P238 for Ariane 5G and G+) solid rocket boosters (SRBs or EAPs from the French Étages d'Accélération à Poudre — ), each weighing about full and delivering a thrust of about . They were fueled by a mix of ammonium perchlorate (68%) and aluminium fuel (18%) and HTPB (14%). They each burned for 130 seconds before being dropped into the ocean. The SRBs were usually allowed to sink to the bottom of the ocean, but, like the Space Shuttle Solid Rocket Boosters, they could be recovered with parachutes, and this was occasionally done for post-flight analysis. Unlike Space Shuttle SRBs, Ariane 5 boosters were not reused. The most recent attempt was for the first Ariane 5 ECA mission in 2009. One of the two boosters was successfully recovered and returned to the Guiana Space Center for analysis. Prior to that mission, the last such recovery and testing was done in 2003.
The French M51 submarine-launched ballistic missile (SLBM) shared a substantial amount of technology with these boosters.
In February 2000, the suspected nose cone of an Ariane 5 booster washed ashore on the South Texas coast, and was recovered by beachcombers before the government could get to it.
Second stage
The second stage was on top of the main stage and below the payload. The original Ariane — Ariane 5G — used the EPS (Étage à Propergols Stockables — Storable Propellant Stage), which was fueled by monomethylhydrazine (MMH) and nitrogen tetroxide, containing of storable propellant. The EPS was subsequently improved for use on the Ariane 5G+, GS, and ES.
The EPS upper stage was capable of repeated ignition, first demonstrated during flight V26 which was launched on 5 October 2007. This was purely to test the engine, and occurred after the payloads had been deployed. The first operational use of restart capability as part of a mission came on 9 March 2008, when two burns were made to deploy the first Automated Transfer Vehicle (ATV) into a circular parking orbit, followed by a third burn after ATV deployment to de-orbit the stage. This procedure was repeated for all subsequent ATV flights.
Ariane 5ECA used the ESC (Étage Supérieur Cryotechnique — Cryogenic Upper Stage), which was fueled by liquid hydrogen and liquid oxygen. The ESC used the HM7B engine previously used in the Ariane 4 third stage. The propellent load of 14.7 tonne allowed the engine to burn for 945 seconds while providing 6.5 tonne of thrust. The ESC provided roll control during powered flight and full attitude control during payload separation using hydrogen gas thrusters. Oxygen gas thrusters allowed longitudinal acceleration after engine cutoff. The flight assembly included the Vehicle Equipment Bay, with flight electronics for the entire rocket, and the payload interface and structural support.European Space Agency, "Ariane 5ECA": http://www.esa.int/Enabling_Support/Space_Transportation/Launch_vehicles/Ariane_5_ECA2 Discussed in context of other launch vehicles in Gérard Maral, Michel Bousquet, and Zhili Sun, Satellite Communications Systems: Systems, Techniques and Technology, sixth edition, London: Wiley, 2020
Fairing The payload and all upper stages were covered at launch by a fairing for aerodynamic stability and protection from heating during supersonic flight and acoustic loads. It was jettisoned once sufficient altitude has been reached, typically above . It was made by Ruag Space and since flight VA-238 it was composed of 4 panels.
Launch preparations With the exception of the solid rocket boosters (for safety and cost reasons), the components were assembled in Europe, and then shipped to French Guyana by boat. Once at Kourou, the components were assembled in the Launcher Integration Building (BIL), then transferred into the Final Assembly Building (BAF) for mating the payload and fairing, before the completed rocket was transferred to the Launch Zone (ZL) for fueling and launch.
Variants Variant Description G The original version was dubbed Ariane 5G (Generic) and had a launch mass of . Its payload capability to geostationary transfer orbit (GTO) was for a single satellite or for dual launches. It flew 16 times with one failure and two partial failures. G+ The Ariane 5G+ had an improved EPS second stage, with a GTO capacity of for a single payload or for two. It flew three times in 2004, with no failures. GS At the time of the failure of the first Ariane 5ECA flight in 2002, all Ariane 5 launchers in production were ECA versions. Some of the ECA cores were modified to use the original Vulcain engine and tank volumes while the failure was investigated; these vehicles were designated Ariane 5GS. The GS used the improved EAP boosters of the ECA variant and the improved EPS of the G+ variant, but the increased mass of the modified ECA core compared to the G and G+ core resulted in slightly reduced payload capacity. Ariane 5GS could carry a single payload of or a dual payload of to GTO. The Ariane 5GS flew 6 times from 2005 to 2009 with no failures. ECA The Ariane 5ECA (Evolution Cryotechnique type A), first flown in 2002 but ending in failure, and first successfully flown in 2005, used an improved Vulcain 2 first-stage engine with a longer, more efficient nozzle with a more efficient flow cycle and denser propellant ratio. The new ratio required length modifications to the first-stage tanks. The EPS second stage was replaced by the ESC-A (Etage Supérieur Cryogénique-A), which had a dry weight of and was powered by an HM-7B engine burning of cryogenic propellant. The ESC-A used the liquid oxygen tank and lower structure from the Ariane 4's H10 third stage, mated to a new liquid hydrogen tank. Additionally, the EAP booster casings were lightened with new welds and carry more propellant. The Ariane 5ECA started with a GTO launch capacity of for dual payloads or for a single payload. Later batches: PB+ and PC, increased the max payload to GTO to . The Ariane 5 ECA flew 72 times from 2002 to 2019 with one failure and one partial failure. ECA+The Ariane 5ECA+ (Evolution Cryotechnique type A+), first successfully flown in 2019, used an improved ESC-D (Etage Supérieur Cryogénique-D). ES The Ariane 5ES (Evolution Storable) had an estimated LEO launch capacity of . It included all the performance improvements of Ariane 5ECA core and boosters but replaced the ESC-A second stage with the restartable EPS used on Ariane 5GS variants. It was used to launch the Automated Transfer Vehicle (ATV) into a circular low Earth orbit inclined at 51.6° and was used 3 times to launch 4 Galileo navigation satellites at a time directly into their operational orbit. The Ariane 5ES flew 8 times from 2008 to 2018 with no failures. ME(cancelled) The Ariane 5ME (Mid-life Evolution) was under development until December 2014 when funding was cut in favour of developing Ariane 6. Last activities for Ariane 5ME were completed at the end of 2015. Vinci upper stage engine, under development for the 5ME, transferred to Ariane 6.
Launch pricing and market competition , the Ariane 5 commercial launch price for launching a "midsize satellite in the lower position" was approximately €50 million, competing for commercial launches in an increasingly competitive market.
The heavier satellite was launched in the upper position on a typical dual-satellite Ariane 5 launch and was priced higher than the lower satellite, on the order of €90 million .
Total launch price of an Ariane 5 – which could transport up to two satellites to space, one in the "upper" and one in the "lower" positions – was around €150 million .
Cancelled plans for future developments
Ariane 5 ME The Ariane 5 ME (Mid-life Evolution) was in development into early 2015, and was seen as a stopgap between Ariane 5ECA/Ariane 5ES and the new Ariane 6. With first flight planned for 2018, it would have become ESA's principal launcher until the arrival of the new Ariane 6 version. ESA halted funding for the development of Ariane 5ME in late 2014 to prioritize development of Ariane 6.
The Ariane 5ME was to use a new upper stage, with increased propellant volume, powered by the new Vinci engine. Unlike the HM-7B engine, it was to be able to restart several times, allowing for complex orbital maneuvers such as insertion of two satellites into different orbits, direct insertion into geosynchronous orbit, planetary exploration missions, and guaranteed upper stage deorbiting or insertion into graveyard orbit. The launcher was also to include a lengthened fairing up to and a new dual launch system to accommodate larger satellites. Compared to an Ariane 5ECA model, the payload to GTO was to increase by 15% to and the cost-per-kilogram of each launch was projected to decline by 20%.
Development Originally known as the Ariane 5ECB, Ariane 5ME was to have its first flight in 2006. However, the failure of the first ECA flight in 2002, combined with a deteriorating satellite industry, caused ESA to cancel development in 2003. Development of the Vinci engine continued, though at a lower pace. The ESA Council of Ministers agreed to fund development of the new upper stage in November 2008.