The wet dress rehearsal for NASA’s Artemis II concluded early Tuesday morning. The SLS (Space Launch System) tanks were successfully loaded with cryogenic propellant after a team was sent out to the launch pad to close out Orion and safely drain the rocket. A wet dress rehearsal is a prelaunch test, concluded to fuel the rocket and to identify any problems that might appear during the launch, and if any problem appears, engineers try to solve it on the spot. NASA began a countdown of approximately 49 hours on 31 January. During the whole operation NASA’s engineers monitored how the cold weather of Florida affected the systems and maintained procedures in place to keep hardware safe.
NASA concludes Artemis II wet dress rehearsal after delays and termination
The Artemis II wet dress rehearsal countdown was terminated at T-5 minutes and 15 seconds after teams detected a liquid hydrogen leak at the tail service mast umbilical. Elevated hydrogen levels had already been observed at the same interface earlier in the countdown, raising concerns as the test progressed.The leak surfaced during tanking. Engineers spent hours working through it, enough to push the timeline out of alignment. At different points, liquid hydrogen flow into the core stage was paused, the hardware was allowed to warm, and propellant flow was adjusted in an effort to settle the seals. The issue never fully cleared.
Additional issues noted during test operations
Other problems surfaced along the way. A valve tied to the pressurisation of the Orion crew module hatch, recently replaced, needed to be retorqued. Closeout tasks took longer than expected. Cold temperatures caused issues with several cameras and pieces of ground equipment. None of those stopped the rehearsal, though they would have drawn more attention on an actual launch day.Audio systems have also been under review in recent weeks, with engineers tracking intermittent communication dropouts between ground teams. Several of those dropouts occurred again during the test.During closeout operations, teams followed updated procedures inside the White Room. Instead of gaseous nitrogen, breathing air was used to purge cavities in Orion’s service module. The change is meant to support safer conditions for personnel assisting the crew and sealing the spacecraft, a small adjustment tested quietly alongside a rehearsal that never quite settled.
Review underway as March remains possible launch window
March remains a possible launch window, though no date has been set. Teams are expected to spend the coming period reviewing data from the test, working through each issue as needed, and returning to additional testing before committing to a target.NASA has said crew safety continues to guide the process. Artemis II astronauts Reid Wiseman, Victor Glover, and Christina Koch, along with Canadian Space Agency astronaut Jeremy Hansen, are expected to return home at the end of the mission, and planning remains focused on that outcome.Agency leadership is also beginning to speak publicly about the test. Alongside a statement released Tuesday by NASA Administrator Jared Isaacman, officials are scheduled to discuss early results from the wet dress rehearsal during a conference later in the day. The briefing is set for 1 p.m. ET (10:30 p.m. IST), a shift from the earlier plan to begin at noon, and will be streamed live on NASA’s YouTube channel.
