Nasa’s Artemis II mission, which recently completed a wet dress rehearsal and was targeting an early March launch window, may now face delays after engineers detected an interruption in helium flow in the rocket. A day after announcing that its ambitious moon mission successfully completed the wet dress rehearsal, Nasa shared overnight observations on Saturday that revealed an interruption in the flow of helium into the Space Launch System (SLS) rocket’s interim cryogenic propulsion stage – a critical system required for launch. Nasa is now evaluating whether the issue will require rolling the rocket and its Orion spacecraft back to the Vehicle Assembly Building (VAB) at Kennedy Space Center in Florida.In a post on X, Nasa Administrator Jared Isaacman said, “After overnight data showed an interruption in helium flow in the SLS interim cryogenic propulsion stage, teams are troubleshooting and preparing for a likely rollback of Artemis II to the VAB at @NASAKennedy. This will almost assuredly impact the March launch window. @NASA will continue to provide updates as they become available.”The announcement came just a day after the four astronauts assigned to the mission entered quarantine in Houston in preparation for the early March launch. The rocket had recently undergone a wet dress rehearsal, simulating launch day operations and fueling up to T-29 seconds, with no evidence of leaks reported during the test. This followed a previous hydrogen leak that had forced Nasa to repeat the prelaunch test earlier this month, USA Today reported.According to Nasa, “Teams are actively reviewing data, and taking steps to enable rollback positions for Nasa to address the issue as soon as possible while engineers determine the best path forward.”To maintain troubleshooting options at both Pad 39B and the VAB, Nasa teams are preparing to remove the pad access platforms installed on February 20. The platforms cannot be removed during periods of high winds, which are forecast for February 22 near the Cape. The space agency further emphasised that while the rollback preparations are underway, engineers are still assessing the best course of action to resolve the helium flow interruption and safeguard the Artemis II launch schedule.