The closeout crew has now closed the side hatch, one of two hatches on the Orion crew module. The remaining hatch that the team is working to close is the Launch Abort System hatch.

This comes after the space agency confirmed that the spacesuits of all four astronauts passed their leak checks while in the Orion module, which once again tested the suits' pressure, ensuring they are airtight.

-ABC News' Briana Alvarado

With the help of their closeout crew, the Artemis II astronauts have entered the Orion crew module, which they named "Integrity."

This mission will be the first time humans travel into space on Orion.

Artemis II will be a crucial step in testing the systems on the spacecraft for future deep space missions back to the moon.

-ABC News' Briana Alvarado

The Artemis II crew has arrived at the launchpad at the Kennedy Space Center in Florida. 

NASA has said the four astronauts remain on track to launch at 6:24 p.m. ET.

The four-person Artemis II crew is heading to Launch Complex 39B at the Kennedy Space Center in Florida.

"It's a great day for us. It's a great day for the team," mission commander Reid Wiseman told a crowd of family members, fans and media after exiting the Operations and Checkout Facility.

The astronauts piled into an Astrovan to transport them across campus to the launch tower.

-ABC News' Briana Alvarado and Mary Kekatos

The Artemis II mission crew is awake and preparing for today's historic lunar flyby.

NASA reported the crew wake-up at around 10:35 a.m. ET.

“Morning routine: Wake up, shave, make the bed, witness something that's never before been seen by human eyes," NASA said. "The Artemis II crew is preparing for today's lunar flyby, when they will see the Moon's far side.”

The lunar flyby is scheduled to commence at 2:45 p.m. ET today, according to NASA.

-ABC News' Briana Alvarado