NASA's gumdrop-shaped Orion capsule, dubbed Integrity, parachuted gently into calm seas off the Southern California coast shortly after 5.07pm US Pacific Time on Friday, concluding a mission that took the astronauts 405,555km away from earth, deeper into space than anyone had flown before.
The Artemis II flight, travelling a total of 1,117,515km in two earth orbits and a climactic lunar flyby, was the debut crewed test flight in a series of Artemis missions that aim to return astronauts to the lunar surface starting in 2028.
The splashdown, under partly cloudy skies about two hours before sunset, was carried by live video feed in a NASA webcast.
"A perfect bullseye splashdown for Integrity and its four astronauts," NASA commentator Rob Navias said moments after the landing.
"We are stable one - four green crew members," mission commander Reid Wiseman radioed just after splashdown, signalling the capsule was steady and all four astronauts were in good shape.
It took NASA and US Navy recovery teams less than two hours to secure the floating capsule and retrieve the four crew members - US astronauts Wiseman, 50, Victor Glover, 49, and Christina Koch, 47, along with Canadian astronaut Jeremy Hansen, 50.
The crew's homecoming was the riskiest test of the mission and its Lockheed Martin-built Orion spacecraft, proving the capsule's heat shield could withstand the extreme forces of re-entry from a lunar-return trajectory.
The capsule plunged into earth's atmosphere at 32 times the speed of sound, with atmospheric friction pummelling its heat shield at temperatures of some 2760 degrees Celsius.
A sheath of ionised gas enveloped the vehicle, causing a planned radio blackout of more than six minutes at the peak of re-entry stress.
The tension broke as contact was re-established and two sets of parachutes were seen billowing from the nose of the free-falling capsule, slowing its descent to about 25km/h before Orion gently hit the water.
Once Navy divers had attached a floating collar to stabilise the capsule, the four astronauts, still wearing their orange flight suits, were helped onto an inflatable raft.
From there, they were hoisted one by one to helicopters hovering overhead and flown a short distance to the nearby navy amphibious transport vessel, the John P Murtha, for further medical examination.
The crew was expected to spend the night aboard the ship and be flown on Saturday to Houston, where they will be reunited with family, NASA said.
The quartet blasted off from Cape Canaveral, Florida, on April 1, aboard NASA's giant Space Launch System rocket, orbiting twice around earth before sailing on for a rare journey around the far side of the moon.
In so doing, they became the first astronauts to fly around earth's only natural satellite since the Apollo program of the 1960s and '70s.
Glover, Koch and Hansen also made history as the first Black astronaut, the first woman and first non-US citizen, respectively, to take part in a lunar mission.
The crew's peak distance of 406,771km away broke the record of roughly 399,117km set in 1970 by the crew of Apollo 13.
The voyage, following the uncrewed Artemis I test flight around the moon by the Orion spacecraft in 2022, marked a critical dress rehearsal for a planned attempt later this decade to land astronauts on the lunar surface for the first time since Apollo 17 in late 1972.
NASA is seeking to achieve a crewed moon landing ahead of China, which is aiming to put its own crews there around 2030.
The agency more broadly aims to establish a long-term lunar presence as a stepping stone to eventual human exploration of Mars.
