Ariane 5 is a European heavy lift launch vehicle that is part of the Ariane rocket family, an expendable launch system used to deliver payloads into geostationary transfer orbit (GTO) or low Earth orbit (LEO). Ariane 5 rockets are manufactured under the authority of theEuropean Space Agency (ESA) and the Centre National d'Etudes Spatiales. Airbus Defence and Space is the prime contractor for the vehicles, leading a consortium of sub-contractors. Ariane 5 is operated and marketed by Arianespace as part of the Ariane programme.Astrium builds the rockets in Europe and Arianespace launches them from the Guiana Space Centre in French Guiana.
Ariane 5 succeeded Ariane 4, but was not derived from it directly. Ariane 5 has been refined since the first launch in successive versions, "G", "G+", "GS", "ECA", and most recently, "ES". ESA originally designed Ariane 5 to launch the Hermes spaceplane, and thus intended it to be human rated from the beginning.
Two satellites can be mounted using a SYLDA carrier (SYstème de Lancement Double Ariane). Three main satellites are possible depending on size using SPELTRA (Structure Porteuse Externe Lancement TRiple Ariane). Up to eight secondary payloads, usually small experiment packages or minisatellites, can be carried with an ASAP (Ariane Structure for Auxiliary Payloads) platform.
As of July 2015 Arianespace has signed contracts for Ariane 5 ECA launches up till 2023, after planned introduction of Ariane 6 in 2020.
Ariane 5 succeeded Ariane 4, but was not derived from it directly. Ariane 5 has been refined since the first launch in successive versions, "G", "G+", "GS", "ECA", and most recently, "ES". ESA originally designed Ariane 5 to launch the Hermes spaceplane, and thus intended it to be human rated from the beginning.
Two satellites can be mounted using a SYLDA carrier (SYstème de Lancement Double Ariane). Three main satellites are possible depending on size using SPELTRA (Structure Porteuse Externe Lancement TRiple Ariane). Up to eight secondary payloads, usually small experiment packages or minisatellites, can be carried with an ASAP (Ariane Structure for Auxiliary Payloads) platform.
As of July 2015 Arianespace has signed contracts for Ariane 5 ECA launches up till 2023, after planned introduction of Ariane 6 in 2020.
Solid boosters
]Ariane 5’s cryogenic H173 main stage (H158 for Ariane 5 G, G+, and GS) is called the EPC (Étage Principal Cryotechnique—Cryotechnic Main Stage). It consists of a large tank 30.5 metres high 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 142 tonnes-force (1,390 kilonewtons). The H173 EPC weighs about 189 tonnes, including 175 tonnes of propellant.
Attached to the sides are two P241 (P238 for Ariane 5 G and G+) solid rocket boosters (SRBs or EAPs from the French Étages d’Accélération à Poudre), each weighing about 277 tonnes full and delivering a thrust of about 722 tonnes-force (7,080 kilonewtons). These SRBs are usually allowed to sink to the bottom of the ocean, but like the Space Shuttle Solid Rocket Boosters they can be recovered with parachutes, and this has occasionally been done for post-flight analysis. (Unlike Space Shuttle SRBs Ariane 5 boosters are not reused.) The most recent attempt was for the first Ariane 5 ECA mission. 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 SLBM shares 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 bybeachcombers before the government could get to it.
Second stage
The second stage is on top of the main stage and below the payload. The Ariane 5G used the EPS (Étage à Propergols Stockables—Storable Propellant Stage), which is fueled by monomethylhydrazine (MMH) and nitrogen tetroxide. The EPS was improved for use on the Ariane 5 G+, GS, and ES. Ariane 5 ECA uses the ESC (Étage Supérieur Cryotechnique—Cryogenic Upper Stage), which is fueled by liquid hydrogen and liquid oxygen.
The EPS upper stage is capable of multiple ignitions, 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.
Fairing
The payload and all upper stages are covered at launch by a fairing, which is jettisoned once sufficient altitude has been reached (typically above 100 km).