Using a limited number of engines, Ariane 5 has an architecture that is both simple and robust. The vehicle consists of a main cryogenic core stage, two solid booster stages, and an upper stage.

The Main Cryogenic Stage
This 30-meter-tall stage is the core of the Ariane 5 launcher and operates on non-toxic cryogenic propellant for just under 600 sec. Its Vulcain engine is ignited seven seconds before the launcher's liftoff, allowing full monitoring during startup and stabilization of thrust.

The Solid Booster Stage
Standing more than 30 meters tall, the two solid boosters deliver more than 90 percent of the total launcher's thrust at the start of flight.

The Storable Propellant Stage
The EPS is the first upper stage developed for Ariane 5. It propels the launcher's payload to its final orbit and provides an accurate orbital injection.