Just a day after NASA announced it was on track to launch its upcoming moon mission, Artemis II, as soon as March 6, the agency revealed a new problem with the mission’s rocket that “almost assuredly” scuttles that plan, according to a social media post by NASA administrator Jared Isaacman.
In a blog post on Saturday, NASA said that engineers had detected an interruption in the flow of helium in the upper stage of the Space Launch System (SLS) rocket. In his social media post, Isaacman confirmed the problem and said that the rocket will be removed from the launchpad and returned to the Vehicle Assembly Building for repair work.
“We will begin preparations for rollback, and this will take the March launch window out of consideration,” Isaacman wrote in a follow-up social media post.
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Engineers are deciding what do next, NASA said in its blog post. The mission’s predecessor, Artemis I, also suffered from a helium problem, Isaacman wrote on social media. It is not yet clear if Artemis II’s issue is the same.
Artemis II has already been delayed numerous times, most recently because of its failed initial “wet dress rehearsal.” This key test involves loading the rocket with fuel, preparing the capsule that will house the Artemis II crew for the duration of the mission for launch and simulating a launch countdown. The first attempt was plagued by hydrogen fuel leaks and other problems. But the second attempt, which took place just days ago, was a success—that’s why NASA had been confident in a March launch date mere hours before this new problem arose.
When it does eventually launch, Artemis II will see four astronauts—NASA’s Christina Koch, Reid Wiseman, and Victor Glover and Canadian astronaut Jeremy Hansen—fly on a 10-day journey around the moon and back. Together, they will observe the moon’s elusive farside and perform critical tests that will help form the basis for Artemis III—NASA’s planned mission to, by 2028, return humans to the lunar surface for the first time in more than half a century.
Editor’s Note (2/23/26): This article was edited after posting to better clarify the descriptions of Jared Isaacman’s social media posts and to reflect an update to NASA’s blog post.