Updated March 20, 2026 — Early Friday at NASA’s Kennedy Space Center, the repaired Artemis II moon rocket began a slow, roughly 12-hour roll back to the launch pad, setting up a delayed April 1 attempt to send four astronauts on a nine-day lunar flyby.
Mounted on an Apollo-era crawler-transporter, the 332-foot Space Launch System and its mobile launch platform left the Vehicle Assembly Building about 12:20 a.m. EDT, about four-and-a-half hours later than planned after high winds along Florida’s Space Coast delayed the start. The roughly four-mile move to Launch Pad 39B was expected to finish around midday, after which teams will reconnect fuel lines, power and data cables and run tests to verify all pad connections and systems.
NASA says the earlier issue that forced an extra fueling test has been addressed and that the next time the SLS is loaded with more than 750,000 gallons of liquid hydrogen and oxygen it will be for launch. Artemis II commander Reid Wiseman and crewmates Victor Glover, Christina Koch and Canadian astronaut Jeremy Hansen entered pre-flight medical quarantine Wednesday night. The quartet plans to travel to Kennedy about a week before the planned liftoff and aims to strap in at 6:24 p.m. EDT on April 1, the opening of a two-hour launch window.
This mission will be the first time astronauts fly atop an SLS rocket and inside an Orion crew capsule. The 2022 Artemis I flight was uncrewed and lacked the life-support systems that will be used on Artemis II. During their first full day in space the crew will check propulsion, navigation, communications and life support systems before setting a course for a lunar swing-by.
Artemis II is the first piloted lunar mission since Apollo 17 in 1972. The crew will perform a free-return trajectory that swings around the far side of the moon and returns for a Pacific Ocean splashdown without entering lunar orbit. If launched as planned, the mission will carry humans farther from Earth than anyone in history. A successful Artemis II would clear the way for follow-on SLS/Orion flights to test rendezvous and docking with moon landers being developed by SpaceX and Blue Origin, with at least one — and possibly two — crewed landings targeted for 2028.
The flight was originally scheduled for early February but was delayed after hydrogen leaks were detected during a rehearsal countdown. That leak was corrected at the pad and a subsequent fueling test completed without major issues, shifting the target to March. Engineers then ran into a separate problem: they were unable to repressurize the rocket’s upper stage with high-pressure helium, which is used to push propellants to engines and purge tanks and lines. Because the upper-stage hardware could not be reached at the pad, the SLS was rolled back into the Vehicle Assembly Building where technicians, using extendable platforms, located out-of-place seals in a quick-disconnect fitting and repaired them. Teams also replaced batteries in the flight termination system, recharged others and replaced seals on a first-stage liquid-oxygen umbilical.
NASA has a limited launch opportunity that runs through April 6. If Artemis II cannot launch in that window, the mission would need to slip roughly three weeks to the next favorable Earth–moon alignment and appropriate lighting and solar power conditions.