ARIANE 5 ECA VEHICLE EQUIPMENT BAY

Toulouse – Last July Astrium Toulouse delivered the first flight model of the new ECA vehicle equipment bay (VEB) for launcher 517 which is scheduled to make its first flight on November 28, 2002. The Stentor and Hotbird 7 satellites will be carried on board. This will be the first flight of the Ariane 5 heavy launcher with a cryogenic upper stage, capable of placing a payload of about 10 t on geostationary transfer orbit.

The VEB made by Astrium in Toulouse has been re-designed (as part of the Ariane 5 Plus programme led by French space agency CNES on behalf of the European Space Agency) to adapt to the new upper stage, to improve the launcher’s performance capabilities, and to reduce costs. This VEB has a lighter structure made of carbon fibre. The structure supports upgraded electronics, using SMDs. It also features guidance units offering higher performance levels and built around a single, three-axis rate gyro.

The ARIANE 5 Vehicle Equipment Bay drives all the flight control and monitoring functions of the launcher.

The flight control commands are generated by onboard computers and dedicated electronics, using the attitude and speed information supplied by guidance units. These computers are also used to send the launcher all the commands required for correct operation, such as motor ignition, stage release, or release of the payloads. A continuous flow of data is also transmitted via the telemetry link to the ground, at a maximum rate of one million bits per second. The functional electric system is fully redundant, i.e.: all equipment items are duplicated. The ECA vehicle equipment bay is a cylindrical structure measuring 5.40 m in diameter and 1.12 m in height. The bay's weight is 950 kg.

This ECA bay is produced as part of the P2 production contract for 20 bays, which also includes two other new types of equipment:

• P1+ bays, which extend the current series. Like the ECA version, these bays have a lighter structure and upgraded electronics, a new separation system ensuring an attenuated dynamic environment during operation. * "ES" bays similar to the previous one, but adapted to ARIANE 5's versatile missions, with multiple re-ignitions of the upper stage, and possible change of the orbit plane.

Since Astrium started operations in Toulouse more than 25 years ago, it has turned out nearly 160 vehicle equipment bays – a clear demonstration of the technical expertise of its teams.