In April and May 2025, NOAA’s Space Weather Prediction Center (SWPC) conducted an interagency exercise in support of NASA’s upcoming crewed mission to the Moon. This event marked the inaugural use of SWPC’s new Space Weather Prediction Testbed (SWPT). The SWPT serves as an operational proving ground i.e., a physical environment that fosters collaboration and enables realistic simulations of forecasting and decision support. Over 70 participants from NASA, DoD, commercial space, and academia worked through realistic radiation storm scenarios using new tools and operational models. The exercise highlighted NOAA’s capacity to deliver mission-critical space weather services and underscored the value of integrated collaboration between forecasters, researchers, and operators.