Overview
- Engineers detected an interrupted helium flow to the SLS interim cryogenic propulsion stage during routine repressurization after a successful wet dress rehearsal.
- NASA Administrator Jared Isaacman said the rollback preparation removes the March launch window from consideration.
- Earliest opportunities now shift to early April, with reported dates of April 1 and 3–6 pending inspections, repairs and readiness reviews.
- Helium is required to purge engines and pressurize liquid hydrogen and oxygen tanks; the vehicle remains in a safe configuration using backup methods while teams diagnose the issue.
- Possible culprits under review include a filter, valve, umbilical interface or onboard check valve; Artemis II will carry Reid Wiseman, Victor Glover, Christina Koch and Jeremy Hansen on a roughly 10‑day lunar flyby to validate SLS and Orion.