Excess hydrogen concentration in a tail service mast umbilical interface had brought the countdown to an end during the first test.

NASA Administrator Jared Isaacman announced on Saturday that Artemis II is likely to be rolled back after issues were discovered overnight.

NASA's second attempt to run a "wet test" of the Space Launch System (SLS) for its Artemis II mission was successful. Following a failure of some seals during the first attempt earlier this month, NASA pushed the launch back to March to conduct additional tests.

NASA is providing a commentary-free, 24-hour livestream of SLS during the WDR, which can be viewed here on Space.com as well as on YouTube. The agency said that it will also air a separate stream featuring important WDR activities; Space.com will simulcast that feed, if it's made available.

NASA halted the flow of liquid hydrogen to its Space Launch System rocket on February 2, 2026, after a leak during the Artemis II wet dress rehearsal exceeded safety thresholds, forcing the agency to push the earliest crewed lunar flyby to March and schedule a second fueling test.