NASA has delayed the Artemis II mission to April 1 following a helium flow problem that rolled the rocket back from the pad, building on prior fixes for hydrogen leaks during fueling tests. This first crewed lunar orbit since 1972 faces ongoing maintenance before returning to the launch site.
Following a successful Wet Dress Rehearsal fueling test in mid-February—after an initial hydrogen leak setback—Artemis II encountered a new issue on February 22. Ground teams could not flow helium into the Space Launch System (SLS) rocket's upper stage during preparations at Kennedy Space Center.
The 322-foot (98-meter) SLS was rolled back to the Vehicle Assembly Building on February 25. Inspections revealed a dislodged seal in the quick disconnect, blocking helium flow. Teams disassembled, repaired, and tested the system at reduced flow rates.
"Engineers are assessing what allowed the seal to become dislodged to prevent recurrence," NASA stated. While in the assembly building, technicians are performing maintenance: activating flight termination system batteries, replacing batteries across stages and boosters, recharging Orion's abort system batteries, and swapping a core stage liquid oxygen seal.
The rocket won't return to Launch Complex 39B until late March. Launch windows open April 1 at 6:24 pm EDT (22:24 UTC) for two hours, with backups on April 3-6.
Artemis II will send four astronauts—commander Reid Wiseman, pilot Victor Glover, mission specialists Christina Koch, and Jeremy Hansen—around the Moon's far side in Orion, testing systems for landings by 2028. This updates the prior March 6 target set after fueling success.
