Here's what will happen with Artemis II after Friday's splashdown off San Diego coast

Thirteen minutes will determine whether NASA's first crewed Moon mission in more than five decades delivers the data it needs to land humans on the lunar surface. Beginning at 7:53 p.m. ET Friday, the Orion capsule "Integrity" will slam into Earth's atmosphere at 34,965 feet per second, roughly 23,840 miles per hour, with four astronauts inside and a heat shield with known design flaws bearing the full load. Splashdown is expected at 8:07 p.m. ET (5:07 p.m. PDT), approximately 50 to 80 miles off the San Diego coast, between San Clemente Island and Catalina Island.

NASA Flight Director Jeff Radigan described re-entry as "13 minutes of things that have to go right." The heat shield is the central concern. During the 2022 Artemis I uncrewed test flight, Orion's heat shield suffered considerably more erosion than engineers predicted. Rather than delay the mission further to replace it, NASA changed the descent profile for Artemis II: instead of the originally planned "skip re-entry" maneuver, which briefly dips into the upper atmosphere to generate lift, the capsule will take a steeper trajectory designed to reduce heat buildup. As the capsule passes through the upper atmosphere, all contact with Mission Control will cut out. Space historian Jordan Bimm of the University of Chicago described that communications blackout as the most stressful moment of the mission.

Recovery is already in place. The USS John P. Murtha, an amphibious transport dock ship based in San Diego, departed Naval Base San Diego on April 7 and is the primary recovery vessel. MH-60S Sea Hawk helicopters from Helicopter Sea Combat Squadron 23 "Wildcards," operating out of Naval Air Station North Island, will track the capsule through the atmosphere and retrieve the crew after splashdown. It is the first NASA-Department of Defense collaboration on lunar crew recovery since Apollo 17 in 1972.

Approximately two hours after splashdown, Orion itself will be extracted via helicopter and transported to the USS John P. Murtha. Once aboard, Commander Reid Wiseman, Pilot Victor Glover, Mission Specialist Christina Koch, and Mission Specialist Jeremy Hansen of the Canadian Space Agency will undergo medical evaluations before the ship returns to shore. The four were selected in April 2023 and trained together for three years, and their 10-day mission set records that will shape the crew medicine data NASA collects: Glover became the first person of color to travel beyond low Earth orbit; Koch became the first woman; Hansen became the first non-American to fly around the Moon; and Wiseman became the oldest person to travel beyond low Earth orbit.

The telemetry and structural data extracted from Orion in the days after splashdown will be among NASA's most consequential technical readouts since the Apollo program ended. Heat shield performance under a crewed re-entry at this velocity will directly inform the path to Artemis III, NASA's planned first crewed lunar landing since December 1972. Artemis III and subsequent missions are already slated to fly with redesigned heat shields. Artemis III will also require astronauts to dock their Orion capsule with a lunar lander in orbit before descending to the surface.

NASA's live coverage begins at 6:30 p.m. ET (4:30 p.m. PDT) Friday. The post-flight analysis that follows will set the terms for how close, and how confidently, NASA can bring humans back to the Moon.