COSMO-SkyMed di Seconda generazione (CSG) Ground Segment is based on an interoperable and multi-mission design, allowing the exhibition of CSG services to external partners and the access through CSG to services belonging to other Earth Observation partners. Moreover CSG Ground Segment design allows supporting the cooperation by expansion through replication of UGS instances according to different access options. This way, the CSG GS will be able to manage Earth Observation Foreign Missions by enabling centralized and multi-mission access in an integrated environment, offering very valuable technological solutions to the Defense and Civilian communities. This paper provides a thorough description of the CSG system access portfolio.