Ariane 5 completes its initial integration

The propulsive elements for Flight 165’s Ariane 5 G vehicle have been
assembled in the Spaceport’s launcher integration building, marking another
step forward in preparations for this upcoming mission.

Completion of the basic launcher was achieved with the installation of
Ariane 5’s vehicle equipment bay, followed by the EPS upper stage.

The vehicle equipment bay is considered the launcher’s “brains,” and is
fitted with the power distribution system, flight control unit, telemetry
system and other components that provide flight guidance, orientation and
sequencing during the mission.

The EPS upper stage has the longest burn time of any propulsive stage on
Ariane 5, and will carry the mission’s French Helios II military
reconnaissance satellite into orbit after separation from the launch
vehicle.

The photo at left shows the upper stage as it is hoisted in the launcher
integration building. Evident in the image are four large aluminum tanks
that contain the MMH fuel and N204 oxidizer (covered with gold-colored
thermal protection), along with the nozzle extending from stage’s Aestus
engine. Also visible are two black bottles with helium that pressurizes the
stage’s fuel/ oxidizer tanks.

In addition to Flight 165’s Helios II primary payload, the mission also will
carry five small secondary payloads.