It’s been a long time coming, but NASA’s next moon rocket is just months from liftoff on its first uncrewed test flight. The Space Launch System (SLS) is a super heavy-lift vehicle capable of delivering 95 tons to Low Earth Orbit, but its primary purpose will be to deliver humans to lunar orbit and, eventually, to the lunar surface. SLS has been in development since 2,011 and it’s faced a series of delays, but launch day is finally within sight. Earlier this month, the rocket was fully stacked for the first time in the Vehicle Assembly Building at the Kennedy Space Center, and the Orion capsule (the spacecraft’s crew cabin) was attached to the top. The full stack stands an impressive 322 feet tall, just shy of the Saturn V’s 363 feet.

NASA Administrator Bill Nelson (a former astronaut himself) told reporters that “with stacking and integration of NASA’s Space Launch System rocket and Orion spacecraft complete, we’re getting closer and closer to embarking on a new era of human deep space exploration…Thanks to the team’s hard work designing, manufacturing, testing, and now completing assembly of NASA’s new rocket and spacecraft, we’re in the home stretch of preparations for the first launch on the Artemis I mission, paving the way to explore the Moon, Mars, and beyond for many years to come.”

With stacking complete, the next major task will be to roll the rocket out to the pad, where a full wet dress rehearsal will take place. The wet rehearsal involves loading propellant into the vehicle and performing a countdown, testing every aspect of the mission just shy of actually blasting off. The exact date for liftoff of Artemis 1 will be determined after the wet dress rehearsal ensures everything is in good working order.