During the final seconds prior to a launch from French Guiana an “anomaly” was detected, and the launch was interrupted and subsequently postponed. The planned launch was scheduled for late-afternoon on September 5th.
“The Ariane 5 and its Intelsat 37e and BSAT-4a payloads immediately switched to a safe mode. Analysis of data is underway to determine the cause of the anomaly. In parallel, the launcher will be transferred back to the Final Assembly Building at the Spaceport in French Guiana – where it is to be returned to a flight-ready condition,” said Arianespace in statement.
The postponement was truly last minute, as the rocket’s main Vulcain engine had already ignited and the two booster engines would have been ignited just seven seconds later and immediately prior to lift-off from the launch pad at the Kourou Space Centre. Had the two booster engines been lit then the launch would have had to happen as they contain solid fuel which, once lit, cannot be paused.
Arianespace said a new date would be announced shortly once the anomaly had been identified.