Ariane 5 - Variants

Variants

• The original version is dubbed Ariane 5 G (Generic) with a launch mass of 737 tonnes. Its payload capability to geostationary transfer orbit (GTO) was initially specified as 5,970 kg (13,200 lb), but was increased after the qualification flights to 6,200 kg (14,000 lb).

• The Ariane 5 G+ had an improved second stage, with a GTO capacity of 6,950 kg (15,300 lb) for a single payload. It flew three times in 2004.

• It was replaced in 2005 by the Ariane 5 GS, with the same EAP boosters as the ECA and ES variants and a first stage based on the later Evolution EPC, but with the original tank volumes and a Vulcain 1B engine. The GS was introduced following the failure of the first Ariane 5 ECA flight - since all the vehicles then in production were ECA versions, it was decided to modify some of them to use the original Vulcain engine while the failure was investigated. It can carry a single payload of 6,100 kg (13,000 lb) to GTO. The last of 6 Ariane 5 GS rockets was launched in 2009.

• The Ariane 5 ECA (Evolution Cryotechnique type A) has a GTO launch capacity of 10,000 kg (22,000 lb) for dual payloads or 10,500 kg (23,000 lb) for a single payload. This variant uses a new Vulcain 2 first-stage engine, and an ESC-A (Etage Supérieur Cryogénique-A) second stage, powered by an HM-7B engine, weighing 2,100 kg (4,600 lb) and carrying 14,000 kg (31,000 lb) of cryogenic propellant. The second stage uses the liquid oxygen tank and lower structure from the Ariane 4's H10 third stage, mated to a new liquid hydrogen tank. The revised Vulcain has a longer, more efficient nozzle with more efficient flow cycle and denser propellant ratio. The new ratio demanded length modifications to the first-stage tanks. Also, the solid EAP casings have been lightened with new welds, and packed with more propellant. The ESC-A cryogenic second stage does not improve the performance to Low Earth orbit compared to Ariane 5G, and for this reason the Ariane 5 ECA will not be used to launch the Automated Transfer Vehicle (ATV).

• The Ariane 5 ES (Evolution Storable) is used to launch the Automated Transfer Vehicle (ATV) into a 260 km circular low Earth orbit inclined at 51.6°. It includes all the performance improvements of Ariane 5 ECA on EPC (Etage Principal Cryogénique—main stage) and EAP (Etage d'Accélération à Poudre—solid rocket booster) stages while the second stage is the EPS (Etage à Propergols Stockable) used on Ariane 5 GS variants. It is estimated that the Ariane 5 ES can put up to 21,000 kg (46,000 lb) in LEO. The first such launch occurred at 04:03 GMT on 9 March 2008.

• The Ariane 5 ES Galileo is a modification of the standard ES version able to launch four Galileo satellites at a time into 23,000 km circular orbits and due to enter service in the latter half of 2014. It will feature modifications to the payload fairing and payload delivery system to grant the ability to launch four satellites into unique orbits in a single launch. The variant was approved in February 2012 and alongside Soyuz launching two at a time will deliver the second Galileo constellation of 16 satellites during 2014 and 2015.

Comparable rockets: Delta IV · Atlas V · Chang Zheng 5 · Angara · Proton · Falcon 9 · H-IIB