As wireless technologies evolve, the demand for robust, high-performance communication beyond conventional terrestrial systems is growing. The NextG research group pioneers the next generations of wireless communication (6G and beyond), focusing on extreme environments such as underwater, space, and highly dynamic (autonomous) vehicles. By advancing wireless communication in these settings, we tackle the unique propagation challenges of radio, acoustic, and optical communications in underwater and space environments. Leveraging artificial intelligence, we enhance resource allocation, network adaptation, and spectrum management, ensuring that future networks dynamically respond to environmental constraints. At NextG, theory, simulation, and experimental validation converge to bridge the gap between fundamental research and real-world deployment. By pushing the boundaries of wireless communication, we aim to shape the future of ubiquitous, intelligent, and resilient networks in the most challenging environments