NASA Rolls Back Artemis II Rocket Amid Helium Leak Issues

NASA has decided to roll back the Artemis II rocket and the Orion spacecraft to the Vehicle Assembly Building at the Kennedy Space Center due to helium leaks that cannot be addressed at the launch pad. The rollback is scheduled for February 25, 2026, and will involve a journey of approximately six kilometers, taking about 12 hours to complete using the Crawler-Transporter 2.

The initial plan was to execute the rollback earlier, but adverse weather conditions, including cold temperatures and high winds, delayed the operation. These conditions interfered with preparations, including the removal of access platforms required for the engineers to conduct their work.

This decision means that the anticipated launch window for the Artemis II crewed lunar flyby mission in March 2026 will not be met. The helium leak was discovered following the second wet dress rehearsal on February 19, 2026. While the propellant loading and countdown simulation proceeded as expected, engineers faced difficulties achieving the necessary helium flow to the Interim Cryogenic Propulsion Stage (ICPS). Helium is crucial for maintaining the engine’s environmental conditions and pressurizing the liquid hydrogen and liquid oxygen tanks.

NASA engineers are currently investigating potential causes of the leak. They are examining the ground-to-rocket helium interface, an upper-stage valve, and an inline filter. Additionally, data from previous troubleshooting for helium pressurization during the Artemis I mission is being reviewed to assist in identifying the issues.

Once the rocket is returned to the Vehicle Assembly Building, teams will install platforms to access the affected areas. Engineers will then diagnose the problem and implement necessary repairs. This rollback preserves the possibility of launching in April 2026, depending on the timelines for repairs and analysis.

Artemis II marks a significant milestone as it is NASA’s first deep-space crewed mission since the Apollo missions over 50 years ago. The mission will feature a crew of four: Commander Reid Wiseman, Pilot Victor Glover, and Mission Specialists Christina Koch and Jeremy Hansen. They are set to embark on a ten-day lunar flyby, making this mission the first integrated test of the Space Launch System (SLS) and Orion spacecraft in cislunar space.

As preparations continue, NASA aims to address these technical challenges to ensure the success of Artemis II and its ambitious goals for lunar exploration.