The launch has been delayed by several days due to unacceptable upper-level winds ... Eye-1 to space for the first time. Vega’s fourth stage, Avum, uses liquid propellant and can be shut ...

But soon after the fourth stage of the Vega ignited its ... of roughly 250 kilometers (155 miles), the Vega’s Attitude Vernier Upper Module (AVUM) failed to maintain the velocity and heading ...