Reshaping 5th Generation Wireless Communications with Gaps in Liquid Crystal Adaptable Infrastructure towards SpaceX Orbital AI Data Centers

Wireless communications, coupled with hardware and software intelligence, are leaping towards a full rollout of the 5th generation (5G) and a bold vision beyond (e.g., 6th generation), as evidenced in the recent plan of SpaceX's AI satellite orbital data centers. For the emerging intersatellite communications, the frontend high-frequency subsystem's performance, e.g., phase-shifting stability, dispersion, and linearity, critically impacts the beam-steering accuracy and hence the reconfigurable functionality of the service. This work identifies critical knowledge gaps in the physics that underpin the reliable hardware rollout of nematic liquid crystal (NLC)-based millimeter-wave reconfigurable devices as key elements for future agile networks. Specifically, we investigate three underexplored areas: (1) the practical physical limits of coaxial NLC tunable devices incorporating necessary guard bands for space applications, (2) the vulnerability and impact of non-terrestrial dielectric leakage in NLC devices, and (3) the performance determinants of NLC-based bandstop filters with adaptive notching functionality, analyzed through the impact of anti-parallel rubbing directions and reference biasing states. A roadmap towards Explainable AI (XAI) with NLC towards 6G is outlined in the outlook.