Flight 157 postponed a few days
Arianespace issued the following press release this afternoon regarding the delay in the launch of the Ariane 5 10-tonne launcher.
The launch of flight 157 has been postponed by a few days following an anomaly that occurred during the final phase of the launch preparation sequence.
At 6.8 seconds before the transmission by the on-board system control to ignite the Vulcain 2 engine, the ground operations control system simultaneously gave the order to open the cryogenic arms and initiate the external igniters (AMF) of the launch table, whose function is to ignite the hydrogen which pre-chills the engine.
The igniter activation status report failed to reach the ground operation control software and as a result the onboard control system did not trigger the ignition sequence as scheduled at -3.0 seconds. Operations then ceased and the launch vehicle, HOTBIRD 7 and STENTOR, and the launch system went into safe mode.
Draining of the cryogenic upper stage via the launch vehicle purge lines is currently in process. The operations will continue until Saturday morning, when the launch vehicle will be transferred back to the Assembly building. At that point it will be possible to ascertain why the AMF ignition was not acknowledged by the ground operations control system.
Rectifying the anomaly and reconfiguring the flight are not expected to take more than a few days. A new launch date will be announced early next week.