Artist's view of the Ariane 5 ECA

An evolution of the generic Ariane 5 launcher, the Ariane 5 ECA features an increased propellant load in its solid booster stages (EAP) and an improved capacity liquid oxygen tank for the cryogenic core stage (EPC) to feed its new Vulcain 2 main engine.

Various upper stages can be fitted on top of the Ariane 5 ECA.
The Ariane 5 ECA (left) features the ESC-A cryogenic upper stage developed around the HM-7B engine, thrust frame and liquid oxygen tank of Ariane 4’s third stage.

The Ariane 5 ECA (right) is fitted with a restartable version of Ariane 5 G storable propellant upper stage (EPS). One of its primary payloads will be the Autonomous Transfer Vehicle (ATV) for resupply and reboost missions to the International Space Station. This version will be introduced in 2005.