Ariane 5 is, as a part of 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 the European Space Agency (ESA) and the Centre National d'Etudes Spatiales (CNES). Astrium, an EADS company, 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 manned mini shuttle Hermes, 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.
By mid 2007, Arianespace has ordered a total of 99 Ariane 5 launchers from Astrium. The first batch ordered in 1995 consisted of 14 launchers, while the second—P2—batch ordered in 1999 consisted of 20 launchers. A third—PA—batch consisting of 25 ECA and 5 ES launchers was ordered in 2004. The latest batch ordered in mid 2007 consist of another 35 ECA launchers. Through these orders, the Ariane 5 will be the workhorse of Arianespace at least through 2015.