NASA is delaying the launch of the Artemis II mission, pushing the earliest possible liftoff to April 2026, after discovering an issue with the flow of helium to the rocket’s upper stage during a wet dress rehearsal last weekend.
The Space Launch System (SLS) rocket, currently on the launchpad at Kennedy Space Center in Florida, will be rolled back to the Vehicle Assembly Building (VAB) on Tuesday, February 24, to address the problem, according to NASA. The rollback, a four-mile journey, will allow engineers to assess and repair the helium flow issue within the rocket’s interim cryogenic propulsion stage (ICPS).
“The quick work to begin preparations for rolling the rocket and spacecraft back to the VAB potentially preserves the April launch window, pending the outcome of data findings, repair efforts, and how the schedule comes to fruition in the coming days and weeks,” NASA stated on Monday.
The Artemis II mission aims to send astronauts Victor Glover, Reid Wiseman, and Christina Koch of NASA, along with Canadian Space Agency astronaut Jeremy Hansen, on a 10-day flight around the Moon. The mission is designed to test the Orion spacecraft’s systems and verify human capabilities for deep space exploration, paving the way for future crewed lunar landings, including the Artemis III mission.
This is not the first delay for the Artemis II mission. NASA had originally targeted February 8 for launch, but a problem identified during the first wet dress rehearsal prompted a postponement. A March 6 launch date was subsequently proposed, but that target has now been abandoned due to the latest issue.
The Artemis II crew had exited quarantine on Saturday evening and were at NASA’s facility in Houston, Texas, when the latest delay was announced.
The mission builds on the success of the uncrewed Artemis I flight in 2022 and represents a key step toward establishing a long-term presence on the Moon and eventually sending crewed missions to Mars, according to NASA.