NASA’s Artemis II mission is set to conclude Friday night as the four astronauts who spent 10 days traveling around the Moon return safely to Earth, marking the first crewed lunar mission since 1972.

NASA astronauts Reid Wiseman, Victor Glover and Christina Koch, along with Canadian Space Agency astronaut Jeremy Hansen, began final preparations aboard the Orion spacecraft Friday morning ahead of re-entry into Earth’s atmosphere.

Orion is scheduled to begin re-entry at 7:53 p.m. Eastern Time and splash down 14 minutes later, at 8:07 p.m. ET, in the Pacific Ocean off the coast of San Diego, California.

During re-entry, the spacecraft will be traveling at nearly 25,000 miles per hour — roughly 30 times the speed of sound. Orion will encounter extreme temperatures of up to 2,760 degrees Celsius while descending from an altitude of about 400,000 feet. A six-minute communications blackout is also expected as plasma builds around the capsule.

The final phase is considered the riskiest moment of the mission. Orion will deploy 11 parachutes to slow from hypersonic speeds to approximately 17 miles per hour before splashing down in the Pacific.

Recovery operations will be carried out by the U.S. Navy vessel USS John P. Murtha, whose rescue and medical teams will help the astronauts exit the capsule and begin post-flight examinations before they return to Houston.

Artemis II achieved several historic milestones. Victor Glover became the first Black astronaut to orbit the Moon, Christina Koch the first woman, and Jeremy Hansen the first Canadian to take part in a lunar mission.

The mission also broke the record for the farthest distance traveled by a crewed spacecraft and successfully tested Orion’s life support and navigation systems, clearing an important step toward Artemis III, NASA’s planned return of astronauts to the lunar surface.