Engineers, proving the failure of the European Vega Launcher flight in July derived the conclusion that super-hot gas emanating from the burning solid propellant had built up within the structure of the second stage rocket booster of the launcher. The buildup caused the launch vehicle to disintegrate minutes after its liftoff from the French Guiana. The launch vehicle was carrying a Falcon Eye 1 reconnaissance satellite built by Airbus for the UAE military. This was disclosed by Avio, the Italian rocket-maker on Monday.
The investigation of the failed launch of July 10 was co-chaired by European Space Agency (ESA) and Arianespace. The probed finally concluded that the launch failed due to a thermo-structural failure that was suffered by the forward dome of theZ23 second stage motor of Vega.
It was the first failure of any Vega launch vehicle following 14 back to back successes. As per the investigators probing into the failure, the first indication of the problem surfaced 130.85 seconds after the lift-off on July 10, when the Z23 motor encountered an unexpected violent incident, which led to the disintegration of the rocket into two parts. The Z23 motor with an upper section is comprised of the Zefiro 9 third stage, the liquid-fueled fourth stage and the Falcon Eye 1 satellite and its payload blanket.
The mission carried an insurance blanket of €369 million or $407 million, which included the price of the satellite along with the launch itself.
As per an official space release, which announced the result of the investigation officially, engineers rules out the likely causes of the mishap, which included a faulty destruct system of Zefiro 23.
The launch sequence till the T + 2 minute, 10-second mark went off perfectly, as planned. The P80 first stage fired perfectly till complete burnout and separation after 2 minutes following the liftoff. The Zefiro 23 motor ignition and 103-second firing sequence went off normally as well.