NASA’s Artemis II mission, the first crewed flight to the moon’s vicinity since the Apollo program, is facing a new delay due to a technical issue with the rocket’s upper stage.
The space agency announced that a targeted launch for March 6 is no longer possible, forcing a rollback of the Space Launch System (SLS) rocket and Orion spacecraft from the launch pad to the Vehicle Assembly Building (VAB) at Kennedy Space Center. The rollback is scheduled for February 24.
The problem originated in the early hours of February 21, when NASA observed an interrupted flow of helium to the SLS rocket’s interim cryogenic propulsion stage. Helium is essential for maintaining proper environmental conditions for the stage’s engine and for pressurizing the liquid hydrogen and liquid oxygen propellant tanks. According to NASA, the systems functioned correctly during wet dress rehearsals, which concluded on February 19. However, teams were unable to properly flow helium during normal operations and reconfigurations following the rehearsal. Operators have since switched to a backup method to maintain conditions for the upper stage engines and the rocket, which remains in a safe configuration.
The rollback to the VAB is a four-mile journey that will take several hours to complete. NASA Administrator Jared Isaacman confirmed on X that this move eliminates the March launch window. The agency noted that the April launch window is potentially preserved, pending the outcome of data findings and repair efforts. A media briefing is planned for this week to discuss the problem and next steps.
The four-person Artemis II crew—Commander Reid Wiseman, Pilot Victor Glover, Mission Specialist Christina Koch, and Canadian Space Agency astronaut Jeremy Hansen—entered quarantine on February 20, one day before the issue was identified. They have since come out of quarantine.
Earlier in 2025, NASA announced an accelerated timeline for the mission, moving the launch up from a previous target of April 2026 after delays occurred in 2024. The launch had already been pushed from early February to March due to issues identified during the wet dress rehearsal. Artemis II is a 10-day mission and the first crewed flight of the SLS rocket, during which astronauts will orbit the moon in the Orion spacecraft.
