An investigation has revealed the cause of the Vega launch failure on flight VV15 which lost the Falcon Eye 1 satellite causing an insurance loss of circa US$416 million. After what appeared to be successful luanch at 0153 GMT from the Kourou Space Centre on 11 July 2019, at T+130s after separation of the first stage and after ignition of the Zefiro 23 second stage which burned for 14 seconds, sudden “violent” anomaly occurred which resulted in the remaining rocket breaking into two parts – the Zefiro 23 second stage as the first part and the third stage with attached AVUM upper stage as the second part.

Mission control in Kourou wonders what went wrong with the Vega launch. Courtesy: Arianespace

The Avio-built rocket operated by Arianespace was detected as having an anomalous trajectory at T+135s and the rocket parts and its Falcon Eye 1 Earth Observation satellite for the UAE Defence Forces did not achieve orbit and fell into the Atlantic Ocean.  A neutralising range-safety destruction command was sent to the remains at 213s into the flight. At 314s telemetry data and signals ceased.

The cause was found by an investigating commission to be a therm-structural failure of the forward dome area of the Zefiro-23 solid rocket stage. While the exact mechanism of this failure is not determined, checks and corrective actions are being implemented to allow flights of the Vega rocket to resume.