Flight 185 is the 41st ARIANE 5 launch and the fifth in 2008. 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 37th commercial mission for ARIANE 5. Launcher 542, the 37th production phase ARIANE 5, is the fifteenth of the 30 PA contract launchers, for which AIRBUS DEFENCE AND SPACE is production prime contractor. 542 is consequently the sixteenth 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 dual-payload configuration using the SYLDA 5 A (6.4m high) system and a long pattern fairing (total height: 17m), the launcher is carrying a Japanese telecommunications satellite, SUPERBIRD 7 in the upper position, and a US telecommunications satellite, AMC 21 in the lower position.