NASA’s Orion spacecraft for the Artemis I mission splashed down in the Pacific Ocean on Sunday, 11 December after a 25.5 day mission to the Moon traveling more than 2,25 million km on a path around the Moon and returning safely to Earth, completing the Artemis I flight test.

Splashdown is the final milestone of the Artemis I mission that began with a successful lift-off of NASA’s Space Launch System (SLS) rocket 16 November from Launch Pad 39B at NASA’s Kennedy Space Centre in Florida. Over the course of 25.5 days, NASA tested Orion in the harsh environment of deep space before flying astronauts on Artemis II.

“The splashdown of the Orion spacecraft – which occurred 50 years to the day of the Apollo 17 Moon landing – is the crowning achievement of Artemis I. From the launch of the world’s most powerful rocket to the exceptional journey around the Moon and back to Earth, this flight test is a major step forward in the Artemis generation of lunar exploration,” said NASA administrator Bill Nelson. “It wouldn’t have been possible without the incredible NASA team. For years, thousands of individuals have poured themselves into this mission, which is inspiring the world to work together to reach untouched cosmic shores. Today is a huge win for NASA, the United States, our international partners, and all of humanity.”

Two lunar flybys

During the mission, Orion performed two lunar flybys, coming within 129 km of the lunar surface. At its farthest distance during the mission, Orion travelled nearly 434 000 km from our home planet, more than 1,000 times farther than where the International Space Station orbits Earth, to intentionally stress systems before flying crew.

“With Orion safely returned to Earth we can begin to see our next mission on the horizon which will fly crew to the Moon for the first time as a part of the next era of exploration,” said Jim Free, NASA associate administrator for the Exploration Systems Development Mission Directorate. “This begins our path to a regular cadence of missions and a sustained human presence at the Moon for scientific discovery and to prepare for human missions to Mars.”

Prior to entering the Earth’s atmosphere, the crew module separated from its service module, which is the propulsive powerhouse provided by ESA (European Space Agency). During re-entry, Orion endured temperatures about half as hot as the surface of the Sun at about 2760 degrees Celsius. Within about 20 minutes, Orion slowed from nearly 40 000 km to about 32 km for its parachute-assisted splashdown.

During the flight test, Orion stayed in space longer than any spacecraft designed for astronauts has done without docking to a space station. While in a distant lunar orbit, Orion surpassed the record for distance travelled by a spacecraft designed to carry humans, previously set during Apollo 13.

“Orion has returned from the Moon and is safely back on planet Earth,” said Mike Sarafin, Artemis I mission manager. “With splashdown we have successfully operated Orion in the deep space environment, where it exceeded our expectations, and demonstrated that Orion can withstand the extreme conditions of returning through Earth’s atmosphere from lunar velocities.”

Recovery teams are now working to secure Orion for the journey home. NASA leads the interagency landing and recovery team on the USS Portland, which consists of personnel and assets from the U.S. Department of Defence, including Navy amphibious specialists, Space Force weather specialists, and Air Force specialists, as well as engineers and technicians from NASA Kennedy, the agency’s Johnson Space Centre in Houston, and Lockheed Martin Space Operations.

In the coming days, Orion will return to shore where technicians will offload the spacecraft and transfer it by truck back to Kennedy. Once at Kennedy, teams will open the hatch and unload several payloads, including Commander Moonikin Campos, the space biology experiments, Snoopy, and the official flight kit. Next, the capsule and its heat shield will undergo testing and analysis over the course of several months.

Artemis I was the first integrated test of NASA’s deep space exploration systems - the Orion spacecraft, SLS rocket, and the supporting ground systems - and was supported by thousands of people around the world, from contractors who built the spacecraft and rocket, and the ground infrastructure needed to launch them, to international and university partners, to small businesses supplying subsystems and components.

Through Artemis missions, NASA will land the first woman and the first person of colour on the surface of the Moon, paving the way for a long-term lunar presence and serving as a steppingstone for astronauts on the way to Mars.