NASA has postponed the Artemis II lunar flyby launch by at least one month after a critical pre-launch wet dress rehearsal at Kennedy Space Center uncovered multiple problems. Teams halted the test when they detected a hydrogen leak while fueling the Space Launch System (SLS) rocket; pressurizing the tank then revealed additional leakage inside the cavity, according to launch director Charlie Blackwell-Thompson.
The rehearsal also exposed issues with the Orion crew capsule. A valve that pressurizes the vehicle required extra attention, closing the hatch took longer than planned, cold temperatures affected cameras, and teams experienced audio dropouts across communications channels. NASA Administrator Jared Isaacman said safety remains the agency’s top priority and that flight operations will proceed only when ready.
Hydrogen leaks previously complicated Artemis I in 2022, and NASA is applying lessons from that uncrewed flight while continuing investigations into the current anomalies. Engineers will focus on repairs and troubleshooting and plan to run another wet dress rehearsal before allowing astronauts to board.
The earliest new launch opportunity is March 6, with additional windows on March 7, 8, 9 and 11. The 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 will return to quarantine about 14 days before the next launch attempt and travel to Kennedy Space Center six days before liftoff.
Artemis II is a roughly ten-day mission to circle the Moon and return to Earth, carrying humans farther into deep space than any have gone before. It will test key Orion systems such as maneuvering and life support ahead of Artemis III, which aims to return humans to the lunar surface. If successful, Artemis II would be the first crewed mission to the Moon since Apollo’s final lunar mission in 1972.