NASA is preparing to roll the Artemis II rocket from its launch site at Kennedy Space Center back into the Vehicle Assembly Building, delaying a mission launching four astronauts on a trip around the moon for at least a month.
Over the weekend, engineers at KSC encountered an issue with the rocket’s helium system. Helium gas is used to pressurize the SLS rocket’s propellant tanks, which store super-cooled liquid hydrogen and oxygen.
Teams were “not able to properly flow helium during normal operations” and had switched to a backup, according to a NASA blog post.
The system, which sits at the top of the rocket and just below the Orion space capsule, can only be serviced while inside NASA’s massive Vehicle Assembly Building.
After discovering the issue, ground teams began preparing the Artemis II for its four-mile trip back to the VAB ahead of the move, which could happen as early as Tuesday. The SLS rocket and Orion spacecraft sit on a mobile launch pad, allowing NASA to move the entire Artemis II stack to and from its hangar.
“I understand people are disappointed by this development,” said NASA Administrator Jared Isaacman on X. “That disappointment is felt most by the team at NASA, who have been working tirelessly to prepare for this great endeavor.”
What comes next?
NASA was targeting a launch next month, with the earliest launch opportunity on March 6. Rolling back the rocket to the VAB takes that launch window off the table. The earliest Artemis II can now launch is now April 1, pending the outcome of a review of the issue and its repair. NASA has not announced a new target date.
The rollback comes just as the launch team completed a successful wet dress rehearsal last week of the rocket’s fueling and countdown. An earlier attempt was cut short after a sensor picked up a hydrogen leak. During last week’s test, that leak was plugged, allowing the team to perform a practice run of launch day.
Isaacman said that during that wet dress rehearsal, the helium system was working properly. Launch teams saw a similar issue with the helium system during the Artemis I mission – an uncrewed flight that launched November 2022.
The four Artemis II astronauts – NASA’s Reed Wiseman, Victor Glover and Christina Koch, and Canadian Space Agency’s Jeremy Hansen – have left quarantine and will remain in Houston until a new launch date is announced.
Artemis II will mark the first time humans venture to the moon – and into deep space – since the final Apollo lunar mission in 1972.
“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,” Isaacman said. “Where we begin with this architecture and flight rate is not where it will end.”
