The launch occurred on time at the rescheduled date of 2022-12-21. At around 3:26 after launch (18:25 in the video), during the burn of the rocket’s Zefiro 40 second stage solid rocket motor, there was a visible brightening of the plume (shown in the small box at the right in the video—ignore the animation at the left which is disconnected from reality) and afterward it began to change as if, perhaps, the stage was tumbling, Kerbal-style. As soon as the trajectory box appears at the bottom of the screen at 18:33 in the video the velocity (Vitesse) can be seen to be falling. Thereafter, the trajectory (while initially rising ballistically) begins to deviate below the green expected trajectory line, By 20:00 in the video (5:04 after launch) the plotted trajectory is falling and continues to do so until telemetry is lost at 21:50 in the video (T+6:52) at an altitude of 47 km. There follows some painful-to-listen-to commentary and finally, at 25:39 in the video, Arianespace CEO Stéphane Israël announces the failure, described as an “underpressure observed on the Zefiro 40” second stage.
This is only the second launch of the Vega C configuration. The first launch on 2022-07-13 was successful.