Jeremy Graeber, Artemis assistant launch director within NASA’s Exploration Ground Systems Program, participates in the first joint integrated launch countdown simulation for Artemis II inside Firing Room 1 of the Launch Control Center on Thursday, Sept. 11, 2025 at the agency’s Kennedy Space Center in Florida. The training exercise involved engineers from Kennedy, Marshall Space Flight Center in Huntsville, Alabama, and Johnson Space Center in Houston coming together to rehearse all aspects of the launch countdown, from cryogenic loading – filling tanks in the SLS (Space Launch System) rocket’s core stage with liquid hydrogen and liquid oxygen – to liftoff. These simulations will help certify that the launch team is ready for Artemis II – the first crewed Artemis mission that will send four astronauts around the Moon and back.