Launch complex No. 3 (ELA-3) is a vast area that brings together all the infrastructure required for the assembly and launch of Ariane 5.
The 200-hectare site consists of two zones 2.8 km apart: the preparation zone and the launch zone. It also includes storage areas for liquid hydrogen and oxygen (the launcher’s oxidiser and fuel), technical buildings and the launch centre for supervising the operations.
The preparation of Ariane 5 begins at the launcher integration building. ArianeGroup’s operators begin by preparing the launcher’s cryogenic main stage. The EAPs (the two boosters) must then be added to it, followed by the upper stage. Finally, the vehicle equipment bay is mounted on top of the launcher. It is the electronic brain that monitors and orchestrates the flight programme commands.
The launcher is assembled vertically.
Ariane 5 on the table!
From the beginning of its preparation to lift-off, Ariane 5 never leaves its launch table. The launch table is a vital interface for the launcher, and connects Ariane 5 to its power source both in the preparation buildings and during a transfer between them. With its 870 tonnes of armoured steel, it also houses the launcher monotoring elements and protects them from the violent phenomena at lift-off.
Once assembled, Ariane 5 goes to the Final assembly building. This is where the operators will install the satellite on top of the launcher. In the case where two satellites are to be launched, the first satellite is mounted on the launcher. It is then covered with the upper composite: this is the assembly of the dual launch adapter, topped by the fairing containing the other satellite.
The configuration operations for the Ariane 5 engines also take place in the Final assembly building.
Once these operations have been completed, Ariane 5 can be moved to the launch zone.
Ariane 5 makes several transfers: From the Launcher integration building to the Final assembly building, or on to the launch zone. These transport operations are extremely precise and require flawless organisation. A truck tows the launcher, on its launch table, on the rails that connect the various facilities. Equipped with 28 gears, the truck accelerates very gradually to 4 km/h, before decelerating smoothly prior to arriving at its destination. Throughout the transfer, Ariane 5 is connected to an ancillary service unit, a 47-metre long “little train” that supplies it with fluids and energy.
Ariane 5 lifts off from the launch zone.
Once rolled out to the launch zone, Ariane 5 is propped against the Cazes tower. This 40-metre high tower protects the launcher from wind and vibration, and supplies it with fluids and electricity. Four lightning rods around the launcher protect it from lightning. Opposite the Cazes tower are the two flues, which are the exhaust pipes for the launcher during lift-off. Finally, the water tower, located a few hundred metres from the zone, sprays the facilities at lift-off to cool them down and protect them from flames and sound vibrations. It is 90 m high and empties in less than a minute.
A large-scale construction project
The Ariane launch complex No. 3 took 10 years of work for its development, construction and qualification. It was started on 14 November 1988 and launched the first Ariane 5 on 4 April 1996. The launch zone underwent several upgrades, such as in 2000, to adapt it to the different versions of Ariane 5.
This building, located 4 km from the launch zone, houses the Ariane 5 “cockpit”, a room dedicated to the remote supervision of operations on the launcher.