https://techcrunch.com/2022/08/16/watch-nasa-rollout-the-mega-moon-rocket-space-launch-system-ahead-of-launch/

NASA engineers have completed final tests of the Space Launch System (SLS), clearing the way for the mega moon rocket to roll out to the launch pad today instead of Friday as originally planned.

The space agency was able to move up the date for the rollout — when a transporter-crawler moves the 322-foot-tall SLS from the Vehicle Assembly Building to launch pad 39B at Kennedy Space Center — because it completed key tests of the rocket’s flight termination system (FTS). The FTS is a critical series of components that ensure a rocket can be safely destroyed after launch in the case of a major failure. Testing of the FTS was “the final major activity” on NASA’s pre-launch to-do list, the agency said.