The rocket is 98 meters long and part of NASA's new lunar program Artemis.
The first, unmanned, trip is planned for August 29.
The rocket will orbit the moon for 42 days before returning to Earth and landing in the ocean.
"The world's most powerful rocket ever - and here it is," said Bill Nelson, NASA administrator, as the rocket was rolled out of the hangar and unveiled at the Kennedy Space Center on Wednesday.
What is the goal of NASA's Artemis program? See the clip above.