VEGA launch vehicle upper stage and payloads in-orbit collision analysis

In-orbit collision and generation of space debris, a potential limiting factor for the spacecrafts operational life, has increasingly caught the public eye, as well as the legislators. The trend of international policies on the matter is expected to get more stringent, with a clear impact on the companies offering access to space. As prime contractor of VEGA launcher ELV had to cope with this context. VEGA is a light launcher designed to lift small payloads in Low Earth Orbit (LEO). Vega is a four stage rocket. In the frame of system design activities, this analysis is aimed to study possible in-orbit collisions among the bodies left into space at the end of mission, included the last stage of the launch vehicle. The in-orbit collision analysis was a key task during the Final Mission Analysis Review of VEGA qualification flight. In this paper ELV tool are proposed, together with the adopted logic for this kind of study.