Day 2 of ELIXIRION Schools 3 & 4 in Barcelona at the Barcelona Supercomputing Center, where students explored non-terrestrial networks, AI, and nanonetworks.Thanks to Dr. Evgenii Vinogradov, Dr. Jordi Perez-Romero, Dra. Irene Vilà Muñoz, & Dr. Sergi Abadal for their talks!