Months after it was rolled back into the Vehicle Assembly Building, the world’s most powerful rocket left the safety of the building to begin its journey to launch to the Moon. The Space Launch System (SLS) with the Orion spacecraft is scheduled to launch to the Moon on November 14.

The rocket left the assembly building on a 6.4-kilometer-long journey to launch pad 39B at NASA’s Kennedy Space Center in Florida. The rocket is being moved onboard the crawler-transporter. The spacecraft has made two attempts to launch in the past, which were marred by several engine issues and fuel leaks.

“Once outside the VAB high-bay doors, the Moon rocket will make a planned pause allowing the team to reposition the crew access arm on the mobile launcher before continuing to the launch pad. The journey is expected to take between eight to 12 hours,” Nasa said in a blog update.

It added that the agency will provide an update once the rocket has arrived at the pad.

Before moving the rocket, engineers replaced the batteries on the interim cryogenic propulsion stage (ICPS), which was powered up for a series of tests to ensure the stage is functioning properly. Teams also recharged, replaced, and reinstalled several of the radiation instruments and the crew seat accelerometer inside Orion ahead of the crew module closure for roll.

The American space agency has made two attempts to launch the rocket on a journey to the Moon, which will mark human’s next attempt at lunar exploration. The two attempts were marred by major complications that included hydrogen leaks and engine issues, which have been fixed.

The $4.1 billion test flight will kick off Nasa’s return to the moon since the Apollo moonshots of the 1960s and 1970s. No one will be inside the crew capsule for the debut launch. Astronauts will strap in for the second mission in 2024, leading to a two-person moon landing in 2025.