An issue with the SLS rocket's helium pressurization system is prompting the move. It can only be worked on while inside NASA's Vehicle Assembly Building.

Weather pending, NASA will roll the SLS (Space Launch System) rocket and Orion spacecraft for Artemis II off the launch pad at the agency’s Kennedy Space Center in Florida as soon as Tuesday, Feb. 24.

After 20 years of development and more than $24 billion, NASA’s Orion spacecraft is poised for its first crewed flight, a 10-day test run that is expected to lead to human missions to the lunar surface. Orion currently is the only spacecraft capable of crewed deep-space travel, but China and SpaceX are making progress on alternative transports.

The Moon rises behind NASA's Artemis II SLS (Space Launch System) rocket and Orion spacecraft atop a mobile launcher at Launch Complex 39B at NASA's