Artemis II Readies For Crewed Moon Flight As Fueling Begins

Engineers planned to begin pumping nearly 760,000 gallons of super-cold liquid oxygen and hydrogen into the 322-foot-tall SLS rocket's two stages starting around 7:34 a.m. ET Wednesday.

The fueling is the final step before a two-hour launch window opening at 6:24 p.m. ET Wednesday for Artemis II, NASA's first piloted moonshot in half a century that will carry three Americans and one Canadian on a roughly 10-day lunar mission.

Engineers said they were optimistic that a repaired quick-disconnect fitting that leaked during a February dress rehearsal would be leak-free, and senior countdown test director Jeff Spaulding said teams were "excited and ready."

Officials said forecasters put odds of favorable weather at 80% and launch controllers will monitor hydrogen leaks during fueling, aiming to keep leak rates below 16% after prior delays from hydrogen leaks and clogged helium lines.

If fueling and vehicle checks go well, the crew will be awakened about two hours after fueling begins, don pressure suits, walk out to pad 39B and could launch anytime between 6:24 p.m. ET and 8:24 p.m. ET Wednesday.