Upper stage for orbital positioning and attitude control. The AVUM+ stage consists of two different sections – one that hosts the propulsion system (APM: AVUM Propulsion Module), and the other which is devoted to the platform that houses the avionics (AAM: Avum Avionics Module).
The APM provides attitude and axial thrust control for the Vega Launcher during the final stages of flight, in accordance with mission requirements. The current standard configuration includes a liquid bi-propellant system for primary manoeuvres which uses nitrogen tetroxide (NTO) as the oxidant and unsymmetrical dimethylhydrazine (UDMH) as the fuel – both propelled by pressurised helium gas – and a cold gaseous nitrogen system (GN2) for attitude control. Total propellant load varies from 460 to 740 Kg, depending on configuration and mission. The AMM avionics module hosts the main components of the launch vehicle’s avionic subsystem.