Artemis II 23rd Cryo Simulation and 24th Terminal Count Simulation

Artemis launch team members participate in an integrated launch countdown simulation for Artemis II inside Firing Room 1 of the Launch Control Center on Wednesday, Dec. 10, 2025. 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. For Artemis II, four astronauts will venture around the Moon, the first crewed mission on NASA’s path to establishing a long-term presence for science and exploration through Artemis.