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NASA now says March is the earliest window for a launch of the Artemis II mission after it found a liquid hydrogen leak during what’s known as a “wet dress rehearsal” this week.
The space agency had been targeting a Feb. 8 launch date for the mission, which will send four astronauts on a 10-day journey around the moon.
“To allow teams to review data and conduct a second wet dress rehearsal, NASA now will target March as the earliest possible launch opportunity for the flight test,” the space agency said in a statement.
The team had begun loading the rocket with millions of litres of hydrogen midday on Monday as part of the rehearsal, before the leak was identified. NASA says its engineers spent several hours troubleshooting the leak around an interface that’s used to route the hydrogen into the rocket’s core stage, putting the team behind.
“Attempts to resolve the issue involved stopping the flow of liquid hydrogen into the core stage, allowing the interface to warm up for the seals to reseat, and adjusting the flow of the propellant,” NASA said in their update.
Problems also came up with a valve on the vessel, while ground audio also dropped out at times during the rehearsal and “closeout operations” took longer than planned, according to NASA.

The mission is the second in the multibillion-dollar Artemis moon program, following an uncrewed flight in 2022. Artemis II, which is crewed by Canadian astronaut Jeremy Hansen and three American astronauts, is a precursor test to the Artemis III mission, which would see the agency’s first astronaut moon landing since 1972.
In a post on X, NASA Administrator Jared Isaacman said rooting out issues like these is “precisely why” wet dress rehearsals are done.
“These tests are designed to surface issues before flight and set up launch day with the highest probability of success,” Isaacman wrote.
“Safety remains our top priority…. We will only launch when we believe we are as ready to undertake this historic mission.”
- Are you going to Florida to watch the Artemis II launch? We want to hear from you. Send an email to [email protected].
As a result of the changed schedule, NASA said the astronauts on the mission will be released from quarantine, which they first entered on Jan. 21 in preparation for the February launch window. They will go back into quarantine about two weeks before the next launch opportunity.

