5G mobile networks will be soon fully available, handling all types of applications and providing services to massive number of users.In this complex and dynamic network ecosystem, an optimized end-to-end satellite support is key to manage requirements imposed by multiple vertical industries requiring full global connectivity. The European space sector acknowledged this as a key opportunity to expand its business towards the massive deployment of broadband services, what resulted in standardization efforts to adapt 5G to satellite needs. In this context, the aim of TRANTOR is to perform a significant step forward by paving the path for the 5G NTN evolution  towards 6G. To do so, TRANTOR targets the in-orbit validation of a complete satellite value chain involving an automated management of satellite resources across multiple bands, satellites, and orbits, and a converged radio access network. Specifically, at the ground segment, TRANTOR targets the development of novel satellite network management solutions, fully integrated in the 3GPP management framework, which allow the significant scaling up of heterogeneous satellite traffic demands and capacities in a cost-effective, highly dynamic, band and orbit agnostic manner. AI governance will be a main pillar here enabling real time radio resource management across multiple satellite systems for efficiently and trustworthy addressing satellite client needs. In parallel, in the user segment, TRANTOR aims to radically increase the flexibility of access architecture by enabling pre-6G non-terrestrial multi-connectivity. It will be supported by the design of a multi-orbit and multi-band antenna for satellite UEs as well as by the development of gNB and UE 5G NTN equipment able to attend the multi-connectivity needs. Finally, TRANTOR aims to introduce security mechanisms to provide resilience to all types of cyber-threads, specially those emerging from the integrated management and multi-connectivity framework proposed.