NASA has delayed the launch of the Artemis II lunar flyby mission by at least a month after problems emerged during a critical pre-launch test at Kennedy Space Center. The wet dress rehearsal on Monday was halted when teams detected a hydrogen leak during fueling of the Space Launch System (SLS) rocket; another leak appeared when the tank was pressurized. Launch director Charlie Blackwell-Thompson said teams troubleshot the initial leak, but pressurization revealed additional leakage inside the cavity.
The rehearsal also uncovered issues with the Orion crew capsule. A valve that pressurizes the vehicle required extra attention, and closing the hatch took longer than expected. Cold-weather effects caused camera problems, and teams experienced audio dropouts across communications channels. NASA Administrator Jared Isaacman said safety remains the agency’s top priority and that NASA will only proceed when ready.
Hydrogen leaks previously challenged Artemis I in 2022, and NASA is applying lessons from that uncrewed flight while continuing investigations. Work now focuses on fixing the problems and conducting another wet dress rehearsal before astronauts will be allowed aboard.
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, plus Canadian Space Agency astronaut Jeremy Hansen—were released from quarantine and will stay in Houston. They will re-enter 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 flown before. It will test critical Orion systems such as maneuverability and life support ahead of Artemis III, which is planned to return humans to the lunar surface. If successful, Artemis II will mark the first crewed mission to the Moon since Apollo’s final lunar mission in 1972.