NASA is fueling its moon rocket in a leak test ahead of a launch attempt as early as next week. Wednesday's demo will determine whether the 322-foot rocket is ready for its first test flight, a lunar-orbiting mission with mannequins in place of astronauts.
Managers want to verify repairs to all the hydrogen leaks that spoiled the first two launch attempts.
Besides replacing seals, NASA altered the fueling process, easing more slowly into the loading of the super-cold liquid hydrogen and oxygen.
Also watch: Your quick guide to Artemis 1, NASA's new mission to the Moon
Once launched, the crew capsule atop the rocket will be the first to orbit the moon in 50 years. Astronauts could climb aboard in a couple years.