The countdown to launch of the Artemis II mission, NASA's first piloted moonshot in half a century, proceeded smoothly Tuesday as engineers and technicians prepared the agency's giant Space Launch System rocket and Orion crew capsule for fueling and blastoff Wednesday evening.

After clearing nonessential personnel from the "blast danger area" and verifying rocket and ground system readiness, engineers planned to begin pumping nearly 760,000 gallons of super-cold liquid oxygen and hydrogen fuel into the 322-foot-tall SLS rocket's two stages starting around 7:34 a.m. ET Wednesday.

The fueling process will take about five and a half hours to complete, and engineers are optimistic a repaired quick-disconnect fitting that leaked during a dress rehearsal countdown in February will prove leak-free this time around.

Artemis II commander Reid Wiseman, Victor Glover, Christina Koch and Canadian astronaut Jeremy Hansen spent the day relaxing, reviewing their flight plans and getting updates on the countdown, among other day-before-launch tasks.

They will be awakened Wednesday about two hours after the start of fueling. After breakfast and a weather briefing, they'll don their bright orange pressure suits and head for pad 39B to strap in for launch at 6:24 p.m., the opening of a two-hour window.

Forecasters continue to predict an 80% chance of favorable weather throughout the window, but warn that possible afternoon cloud buildups and isolated showers could prompt brief delays to allow time for clouds or rain to move out of the launch area.

Jeff Spaulding, NASA's senior countdown test director and a space shuttle veteran, said engineers and technicians working in the launch control center "are excited and ready to go on this, this first chapter on our way back to the moon since the 1970s."

He said engineers were not working any significant technical problems going into the final day of the countdown.

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