Flight 171 is the 27th Ariane 5 launch and the second in 2006. An ARIANE 5 ECA (Cryogenic Evolution type A), the most powerful version in the ARIANE 5 range, will be used for this flight.
This will be the 23rd commercial mission for Ariane 5. Launcher 529, the 23rd production phase Ariane 5, is the second of the 30 PA contract launchers, for which Airbus Defence and Space is production prime contractor. 529 is consequently the second complete launcher to be delivered to Arianespace, integrated and checked out under Airbus Defence and Space responsibility in the Launcher Integration Building (BIL).
In a multi-payload configuration using the SYLDA 5 "E" (300 mm stretched) system, and a middle pattern fairing, the launcher is carrying two telecommunications satellites: the satellite SATMEX 6 in the upper position and the satellite THAICOM 5 in the lower position.