The inquiry commission mandated after the accident of the light launcher of Arianespace occurred on July 11 presented its conclusions. The flight resumption of Vega is expected for the first quarter of 2020.
For the record, on July 11, the European light-weight launcher Vega was destroyed in flight, for the first time in 7 years and a half of career and 15 missions. The event occurred a little over two minutes after the lift-off, when the ignition of the second stage developed by Avio, the Zefiro 23 (Z23), was switched on.
An inquiry commission was immediately called, to analyze the reasons for the failure and to define the measures that need to be implemented for the return to flight of the launcher. Co-chaired by Toni Tolker-Nielsen (Inspector General of the European Space Agency) and Roland Lagier (Senior Vice President of Technical and Quality of Arianespace), it also included experts from Avio and the CNES. It issued the results of its work on September 4.
“Possible” cause.
The press release issued today by Arianespace reports that the inquiry commission concludes that all the operations of preparation and chronology of the launch VV15, the operation of the first stage P80, then the ignition phase of the engine Z23 proceeded in a nominal way.
The propulsion of the Z23 was consistent with previous flights for 14 seconds and 25 milliseconds, until an “anomaly” occurred at H0 + 130 seconds and 850 milliseconds of flight.
The “most probable” cause of the anomaly would be “a thermo-structural failure” in the forward dome area of the Z23 motor. The tracks of inadvertent activation of the Z23 neutralization system the engine or act of malevolence, as we have sometimes read (especially in some Italian media speculating that the payload was an Emirati reconnaissance satellite).
Optimism?
In addition to this cautious explanation, the inquiry commission made two main recommendations for a flight resumption of Vega in the first quarter of 2020: “an exhaustive verification plan of [these] findings based on analyses and tests” as well as “corrective actions on all subsystems, processes and equipment concerned.”
We understand that new investigations are expected, potentially followed by changes for the Z23, and therefore validation tests, all in less than seven months...