Getting back to the moon is the primary goal of NASA’s Artemis program, but what do we do once we get there? That is the challenge tackled by a group of students at the University of Illinois Urbana-Champaign, who wrote a proposal for a lunar infrastructure module they call the Trans-lunar Hub for Exploration, ISRU, and Advancement—or THEIA, after the proposed object that crashed into the Earth that created the moon as we know it today.