Non-Terrestrial Networks for Space Vehicles Beyond 6G: Applications, Architecture, and Capacity Limits

Non-Terrestrial Networks (NTNs) are becoming in-creasingly popular in serving ground and airborne users on the way from 5G to 6G networks. In this work, we present and analyze a novel attractive use case for satellite networks - serving other satellites and space vehicles used for scientific and commercial missions. We start by presenting our visionary approach and its rationale from technical and commercial perspectives. We then discuss possible system architectures to implement such a service in existing and forthcoming NTNs. We finally present a simple first-order case study, illustrating performance gains with the proposed approach when using both existing Ku-band wireless links (18 GHz) and currently under development sub-terahertz links (220 GHz). Our preliminary findings confirm that, if implemented properly, such a vision may offer up to an order of magnitude improvement in capacity, contact time, and energy efficiency for next-generation scientific, military, and commercial satellites.