NASA started making final preparations for the Artemis 2 mission in early January, with the hope of opening its launch window as soon as February 6. After issues appeared during the mission’s wetsuit rehearsal in the early hours of February 3, however, the agency had to push back the earliest opportunity to launch in March.

“With more than three years between SLS launches, we fully expect to encounter challenges. That’s exactly why we conduct wet dress rehearsals. These tests are designed to deal with issues before the flight and set up launch day with the highest probability of success,” Administrator of NASA Jared Isaacman say that in X.

During a wetsuit rehearsal, the spacecraft that will be used for a mission is filled with propellants to simulate actual preparations and countdowns to takeoff. NASA explained that the Space Launch System of Artemis 2, already on the launch pad, suffered a liquid hydrogen leak that engineers spent hours troubleshooting. They finally filled all the rocket tanks and began the countdown to launch. But with approximately five minutes left in the countdown, the ground launch sequencer automatically stopped due to the increased rate of leakage of liquid hydrogen in the spacecraft.

The agency admitted that they still have other issues that need to be fixed based on what happened during the rehearsal. It should ensure that cold weather does not affect the mission’s equipment during the actual launch in the same way as the test. The Orion crew module hatch pressurization process is taking longer than expected, and that won’t happen on launch day. NASA also had to fix audio communication channels for its ground teams after they went down several times during rehearsals. Artemis’ ground crew will review the data from the wet dress rehearsal and resolve the aforementioned problems. NASA needs to do another test to confirm they are taken care of before announcing the mission’s launch window.