NASA's crewed Artemis II launch gets pushed back again, this time due to a helium issue

Source: Engadget

Background

NASA’s Artemis II is the agency’s first crewed mission to the Moon’s vicinity since the final Apollo flight over 50 years ago. The mission will use the Space Launch System (SLS) rocket and the Orion spacecraft for a 10‑day lunar flyby. Earlier in the year, NASA announced an accelerated timeline, moving the launch from an original April 2026 target to early 2025, then to early February 2025, and later to a March window.

Helium Flow Issue

During the early hours of February 21, NASA detected an interrupted flow of helium to the SLS’s interim cryogenic propulsion stage (ICPS). Helium is required to:

• Maintain proper environmental conditions for the upper‑stage engine.
• Pressurize the liquid‑hydrogen and liquid‑oxygen propellant tanks.

The upper stage performed correctly during Artemis II’s wet‑dress rehearsals, but after the rehearsal concluded on February 19, the helium flow could not be re‑established during normal operations and reconfigurations. Teams are currently using a backup method to keep the upper‑stage environment stable while the rocket remains in a safe configuration.

Impact on Launch Schedule

Because the helium issue requires the SLS to be rolled back from the launch pad to the Vehicle Assembly Building (VAB) for troubleshooting and repairs, the March 2025 launch window is no longer viable. NASA plans to transport the rocket and Orion spacecraft—a four‑mile move that will take several hours—targeting February 24 for the rollback.

A media briefing is scheduled later this week to discuss the findings and next steps. NASA’s blog notes that the effort potentially preserves the April 2025 launch window, pending the outcome of data analysis, repair work, and schedule adjustments in the coming weeks.

Crew Status

The Artemis II crew consists of:

• Commander: Reid Wiseman
• Pilot: Victor Glover
• Mission Specialist: Christina Koch
• Mission Specialist / Canadian Space Agency astronaut: Jeremy Hansen

The crew entered quarantine on February 20, a day before the helium issue was identified. They have since been released from quarantine.

Timeline Overview