NASA announced it is evaluating whether to roll the 322-foot Space Launch System rocket back to its hangar for repairs following an interrupted helium flow detected during preparations for Artemis II. Officials also said the work could potentially be completed at the launch pad.

The issue is confined to the SLS rocket’s interim cryogenic propulsion stage, the upper stage responsible for placing the Orion crew capsule into a high-altitude orbit around Earth after liftoff. The stage is later designed to separate and serve as a docking practice target for the astronauts as part of preparations for future lunar missions.

Hydrogen fuel leaks had already delayed the lunar fly-around mission by about a month. A second fueling test earlier this week showed minimal leakage, giving managers confidence to target a March launch before the latest technical concern emerged.

The four astronauts assigned to Artemis II entered a mandatory two-week quarantine Friday night to avoid illness ahead of the planned flight. “I understand people are disappointed by this development,” NASA Administrator Jared Isaacman said, adding that the team had worked tirelessly to prepare for the mission.

Artemis II would mark the first crewed lunar mission since the Apollo era, when 24 astronauts traveled to the moon between 1968 and 1972. The Artemis program has completed one uncrewed lunar-orbiting test flight in 2022, which also experienced hydrogen fuel leaks and a helium issue prior to launch. A crewed moon landing under Artemis remains several years away.