KENNEDY SPACE CENTER — After being delayed by a storm, NASA’s Artemis’ Space Launch System (SLS) rocket and the Orion capsule arrived at Launch Pad 39B early Wednesday morning after a nearly 10-hour journey.

And it took that long for the crawler-transporter to travel from the Vehicle Assembly Building to Launch Pad 39B. From start to finish, it was a four-mile trip, from 10 p.m. EDT, Tuesday, to around 7:30 a.m. EDT, Wednesday, the space agency stated.

Originally, the rollout of the Artemis I Moon rocket was supposed to begin at 9 p.m. EDT, but it was delayed due to a storm.

And NASA was ahead of schedule for the rollout: Originally, it was slated for Thursday, Aug. 18, but the space agency announced earlier this week that it was targeting Tuesday.

NASA named the mission to return to Earth’s lunar neighbor Artemis, as a homage to the Apollo moon landing. In Greek mythology, Artemis is the twin sister of Apollo and the goddess of the moon. (File photo)

Understanding the Artemis I mission

The rollout is to prepare for the Artemis I mission. The Artemis I mission is an uncrewed flight test that is designed to provide information to researchers that will be used for the crew missions Artemis II in 2024 (where astronauts will have a lunar flyby) and the Artemis III in 2025, where humans will return to the moon.

One of the Artemis I’s mission objectives is to test Orion's heat shield.

“Our first and our primary objective is to demonstrate Orion’s heat shield at lunar re-entry conditions. So we want to demonstrate that it can withstand the high speed and high heat that the spacecraft will encounter when it re-enters the Earth’s atmosphere,” said Artemis Mission Manager Mike Sarafin during a teleconference back in July.

As the uncrewed SLS and Orion sit on the launch pad — well, not entirely uncrewed as Mannequin Commander Moonikin Campos will be in the capsule to test its systems — NASA technicians and engineers will configure systems and hook up propellant lines.

“Teams have worked to refine operations and procedures and have incorporated lessons learned from the wet dress rehearsal test campaign and have updated the launch timeline accordingly,” NASA stated on Thursday.

This is the third time the pair have been on the launch pad: Once in March when a dress rehearsal was canceled due to a valve issue and a second dress rehearsal in June, which was successful.

Both the SLS rocket and the Orion capsule will be parked at the launch pad until liftoff, which is currently scheduled for Monday, Aug. 29.