Vega fourth stage

The Vega fourth stage, the Attitude and Vernier Module (AVUM) performs the following functions:

• roll control during 2nd, 3rd and 4th stage flights
• attitude control during coasting phase
• correction of axial velocity error due to solid rocket motor performance scatter
• generation of the required velocity change for orbit circularisation
• satellite pointing
• payload(s) release manoeuvres