Ariane 5
Ariane 5 is a retired European heavy-lift space launch vehicle operated by Arianespace for the European Space Agency. It was launched from the Guiana Space Centre in French Guiana. It was used to deliver payloads into geostationary transfer orbit, low Earth orbit 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, 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 carrier system. Up to three, somewhat smaller, main satellites are possible depending on size using a SPELTRA. Up to eight secondary payloads, usually small experiment packages or minisatellites, could be carried with an ASAP 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 was called the EPC. It consisted of a diameter by high tank with two compartments, one for liquid oxygen and one for liquid hydrogen, and a Vulcain 2 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 solid rocket boosters, each weighing about full and delivering a thrust of about. They were fueled by a mix of ammonium perchlorate and aluminium fuel and HTPB. 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 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, which was fueled by monomethylhydrazine 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 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, 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.
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, 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, then transferred into the Final Assembly Building for mating the payload and fairing, before the completed rocket was transferred to the Launch Zone for fueling and launch.Variants
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 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.In 2009, EADS Astrium was awarded a €200 million contract, and on 10 April 2012 received another €112 million contract to continue development of the Ariane 5ME with total development effort expected to cost €1 billion.
On 21 November 2012, ESA agreed to continue with the Ariane 5ME to meet the challenge of lower priced competitors. It was agreed the Vinci upper stage would also be used as the second stage of a new Ariane 6, and further commonality would be sought. Ariane 5ME qualification flight was scheduled for mid-2018, followed by gradual introduction into service.
On 2 December 2014, ESA decided to stop funding the development of Ariane 5ME and instead focus on Ariane 6, which was expected to have a lower cost per launch and allow more flexibility in the payloads.
Solid propellant stage
Work on the Ariane 5 EAP motors was continued in the Vega programme. The Vega 1st stage engine – the P80 engine – was a shorter derivation of the EAP. The P80 booster casing was made of filament wound graphite epoxy, much lighter than the current stainless steel casing. A new composite steerable nozzle was developed while new thermal insulation material and a narrower throat improved the expansion ratio and subsequently the overall performance. Additionally, the nozzle had electromechanical actuators which replaced the heavier hydraulic ones used for thrust vector control.These developments could maybe have made their way back into the Ariane programme, but this was most likely an inference based on early blueprints of the Ariane 6 having a central P80 booster and 2-4 around the main one. The incorporation of the ESC-B with the improvements to the solid motor casing and an uprated Vulcain engine would have delivered to LEO. This would have been developed for any lunar missions but the performance of such a design might not have been possible if the higher Max-Q for the launch of this launch vehicle would have posed a constraint on the mass delivered to orbit.
Ariane 6
The design brief of the next generation launch vehicle Ariane 6 called for a lower-cost and smaller launch vehicle capable of launching a single satellite of up to to GTO. However, after several permutations the finalized design was nearly identical in performance to the Ariane 5, focusing instead on lowering fabrication costs and launch prices., Ariane 6 was projected to be launched for about €70 million per flight, about half of the Ariane 5 price.Initially development of Ariane 6 was projected to cost €3.6 billion. In 2017, the ESA set 16 July 2020 as the deadline for the first flight. The Ariane 6 successfully completed its maiden flight on 9 July 2024.