NASA Postpones Artemis II Launch to Address Rocket's Helium Flow Issue

NASA is set to roll back the Artemis II Space Launch System (SLS) rocket and Orion spacecraft from Launch Pad 39B to the Vehicle Assembly Building (VAB) at Kennedy Space Center on Wednesday, February 25, to address a helium flow issue in the rocket's upper stage. The rollback is scheduled to commence around 9 a.m. EST and is expected to take up to 12 hours to complete.

The decision follows the detection of an interruption in helium flow within the SLS's interim cryogenic propulsion stage during overnight data reviews on February 21. Helium is essential for pressurizing the rocket's propellant tanks, which hold approximately 730,000 gallons of liquid hydrogen and liquid oxygen.

This development has led NASA to postpone the Artemis II mission, originally targeted for a March launch window. The next available launch opportunities are in early and late April, though specific dates have not been confirmed.

Artemis II aims to send four astronauts—NASA's Reid Wiseman, Victor Glover, and Christina Koch, along with the Canadian Space Agency's Jeremy Hansen—on a roughly 10-day mission around the Moon and back to Earth. This mission marks NASA's first crewed lunar flight since the Apollo era over 50 years ago.

Once back in the VAB, teams will install platforms to access the area of the helium flow issue and begin necessary repairs. Additionally, they will replace batteries in the flight termination system and the upper stage.

NASA will continue to provide updates as the situation develops and as new launch dates are determined.