Fifty years after the last Apollo mission, the Artemis program is poised to take up the baton of lunar exploration with a test launch on Monday of NASA's most powerful rocket ever.
The goal is to return humans to the Moon for the first time since the last Apollo mission in 1972—and eventually to Mars.
The 322-foot (98-meter) Space Launch System (SLS) rocket is scheduled to blast off at 8:33 am (1233 GMT) from the Kennedy Space Center (KSC) in Florida.
The mission, more than a decade in the planning, may be uncrewed, but is highly symbolic for NASA, which has been under pressure from China and private rivals such as SpaceX.
Hotels around Cape Canaveral are booked solid with between 100,000 and 200,000 spectators expected to attend the launch.
The massive orange-and-white rocket has been sitting on KSC's Launch Complex 39B for a week.
"Ever since we rolled out to the pad last week, you can feel the excitement, the energy," said Janet Petro, director of KSC. "It's really, really palpable."
The objective of the flight, baptized Artemis 1, is to test the SLS and the Orion crew capsule that sits atop the rocket.
Mannequins equipped with sensors will take the place of crew members, recording acceleration, vibration and radiation levels.
The Artemis 1 rocket on Launch Pad 39B at the Kennedy Space Center.