NASA has postponed the Artemis II lunar fly-by by at least a month after critical problems surfaced during a wet dress rehearsal at Kennedy Space Center. Teams began fueling the Space Launch System rocket when sensors detected a hydrogen leak. After crews troubleshooted that leak, a second leak appeared when the tank was pressurized.
Launch director Charlie Blackwell-Thompson said the leak appeared quickly during pressurization. Hydrogen leaks also affected the uncrewed Artemis I mission in 2022; although lessons from that flight were applied to Artemis II, NASA officials say further investigation is required.
The rehearsal also exposed several issues with the Orion capsule. A pressurization valve required extra attention, teams took longer than expected to close the hatch during practice without crew on board, cold temperatures interfered with cameras, and there were audio dropouts across communications channels.
On social media, NASA reiterated that safety remains the agency’s top priority and that it will only launch when ready. Blackwell-Thompson called the day successful in many respects while acknowledging additional work is needed.
Engineers will address the problems and conduct another wet dress rehearsal before approving a crewed launch. NASA is targeting a March launch window, with the earliest opportunity on March 6 and additional openings on March 7, 8, 9 and 11.
The Artemis II crew — NASA astronauts Reid Wiseman, Victor Glover and Christina Koch, and Canadian Space Agency astronaut Jeremy Hansen — were released from quarantine and will remain in Houston. They are scheduled to re-enter quarantine about 14 days before the next launch attempt and travel to Kennedy Space Center six days before liftoff.
If launched, Artemis II will carry the four astronauts on an approximately ten-day mission to circle the moon and return to Earth, traveling farther into deep space than any humans have gone. The flight will test key Orion systems, including maneuvering and life support, ahead of Artemis III, which aims to return humans to the lunar surface. Artemis II would be the first crewed lunar mission since Apollo’s final moonflight in 1972.