U.S. Navy divers could be seen preparing to deploy from the well deck of the USS John P. Murtha, which will retrieve the crewmembers and NASA's Orion spacecraft once they splash down off the coast of San Diego.

Members of the crew can be seen in their orange spacesuits now while at the controls of the Orion spacecraft ahead of their reentry.

Here's a look at the "carefully timed sequence" of the final stages of Orion's descent, according to NASA. All times Eastern.

7:33 p.m.: Orion's crew module will separate from the European Service Module, exposing the heat shield that will protect the spacecraft as it travels through the Earth's atmosphere.

7:37 p.m.: Orion will perform an 18-second raise burn that fine-tunes the reentry angle of the spacecraft to minimize the time the heat shield will experience high temperatures.

7:53 p.m.: Orion will make first contact with the upper atmosphere, beginning a planned 6-minute communications blackout. The crew is expected to experience up to 3.9 Gs as the spacecraft travels nearly 35 times the speed of sound.

7:59 p.m.: NASA will regain communications with the crew.

8:03 p.m.: At around 22,000 feet in altitude, drogue parachutes will deploy to help slow the capsule ahead of splashdown.

8:04 p.m.: Three main parachutes will deploy at around 6,000 feet, reducing Orion's speed to less than 136 mph.

8:07 p.m.: Orion will splash down in the Pacific Ocean, off the coast of San Diego, having slowed to 20 mph.

The U.S. Geological Survey warned residents of Southern California that they should expect to hear a sonic boom from the Artemis II reentry in a few hours.

The sonic boom is expected between approximately 5-5:15 p.m. PT, it said.

The Artemis II crew named a crater on the moon, sitting on the boundary of the near side and far side, after mission commander Reid Wiseman’s late wife, Carroll.

Carroll Wiseman passed away in 2020 after a five-year battle with cancer, according to her obituary.

"We lost a loved one. Her name was Carroll. The spouse of Reid, the mother of Katie and Ellie," Canadian Space Agency astronaut and mission specialist Jeremy Hansen said earlier on Monday, tearing up. "It's a bright spot on the moon. And we would like to call it Carroll."

The crew shared a long group hug afterwards.

For another crater on the far side of the moon, Hansen said the crew would like to name it "Integrity," in honor of the name the astronauts have given the spacecraft that carried them farther into space than any other human in history.

-ABC News' Briana Alvarado