NASA’s plans to send astronauts around the Moon for the first time in more than half a century have hit another setback. Engineers troubleshooting the Artemis II mission encountered problems repressurizing helium tanks in the upper stage of the Space Launch System (SLS) rocket late Friday, forcing officials to order a rollback of the towering vehicle from Launch Complex 39B to the Vehicle Assembly Building (VAB) for further investigation.
NASA’s Artemis II SLS (Space Launch System) rocket and Orion spacecraft stand vertical on mobile launcher 1 at Launch Complex 39B at NASA’s Kennedy Space Center in Florida. Credit: NASA/Ben Smegelsky
The move effectively eliminates any chance of launching in March and shifts the earliest possible liftoff to early April, NASA officials confirmed Saturday.
The issue surfaced after what had otherwise been a strong performance during a full “wet dress rehearsal” countdown that concluded Thursday. During that test, teams successfully loaded more than 750,000 gallons of supercold liquid hydrogen and liquid oxygen propellants into the SLS rocket without the hydrogen leaks that plagued earlier attempts.
Pressurized helium plays a critical role in rocket operations. It is used to force propellants toward engines for ignition and to purge fuel lines before cryogenic propellants begin flowing. Engineers now face an unresolved problem preventing helium from flowing back into the rocket’s upper stage tanks following the test.
“Regardless of the potential fault, accessing and remediating any of these issues can only be performed in the VAB,” NASA Administrator Jared Isaacman said in a statement posted on X. “We will begin preparations for rollback, and this will take the March launch window out of consideration.”
Because the upper stage systems are not fully accessible at the pad, the 322-foot-tall rocket must be transported back inside the cavernous assembly building for detailed inspections and repairs.
The delay marks the latest scheduling change for Artemis II, which had already slipped from an earlier target after hydrogen leaks were discovered during an initial fueling rehearsal. After completing a second, largely successful fueling test this week, managers had been preparing for a March 6 launch attempt.
However, the lunar launch calendar is constrained by orbital mechanics. Specific alignments between Earth and the Moon are required to meet trajectory, lighting and recovery conditions for the 10-day mission. The current launch window closes March 11. The next viable opportunities open April 1, 3, 4, 5 and 6.
With the rollback now required, early April is the soonest the mission could realistically fly.
Astronauts Stand Down from Quarantine
Artemis II will carry four astronauts — Reid Wiseman, Victor Glover, Christina Koch and Canadian Space Agency astronaut Jeremy Hansen — on a journey around the far side of the Moon and back. The mission is designed to thoroughly test the Orion spacecraft and SLS systems in deep space before NASA attempts a crewed lunar landing under Artemis III, currently targeted for 2028.
Hoping for a March launch, the four crew members entered pre-flight medical quarantine at Johnson Space Center on Friday evening and were scheduled to travel to Kennedy Space Center on March 1. With the launch now postponed, they will exit quarantine and await further updates.
“I understand people are disappointed by this development,” Isaacman said. “That disappointment is felt most by the team at NASA, who have been working tirelessly to prepare for this great endeavor.”
Artemis II represents the first crewed lunar mission since the Apollo era. NASA views it as a pivotal step toward establishing a sustained human presence on and around the Moon — including plans for a lunar base and regular missions in the coming decade.
Isaacman acknowledged the program’s challenges, drawing parallels to the setbacks experienced during the 1960s race to the Moon.
“There are many differences between the 1960s and today, and expectations should rightfully be high after the time and expense invested in this program,” he said. “We will return in the years ahead, we will build a Moon base, and undertake what should be continuous missions to and from the lunar environment. Where we begin with this architecture and flight rate is not where it will end.”
For now, NASA engineers will focus on resolving the helium system issue inside the VAB — a reminder that even after a successful fueling rehearsal, spaceflight remains an unforgiving technical endeavor.
Add comment
Comments