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The Artemis I mission — a 25½-day uncrewed test flight around the moon intended to pave the way for future astronaut missions — came to a memorable end when NASA’s Orion spacecraft made a successful ocean splash on Sunday.
The spacecraft finished the last leg of its journey, approaching the thick inner layer of Earth’s atmosphere after a 239,000-mile (385,000-kilometer) journey between the moon and Earth. It splashed down into the Pacific Ocean off Mexico’s Baja California at 12:40 a.m. ET Sunday.
This last step was one of the most important and dangerous parts of the mission.
But after he crashed, Rob Navias, the NASA commentator who ran Sunday’s broadcast, called the reentry process “textbook.”
“I’m overwhelmed,” NASA Administrator Bill Nelson said Sunday. “This is an extraordinary day.”
The capsule is now floating in the Pacific Ocean, where it will remain until nearly 3 p.m. ET as NASA gathers additional data and runs some tests. That process, like the rest of the mission, is designed to ensure that the Orion spacecraft is ready to fly with astronauts.
“We test all the heat that has come and generated on the capsule. We want to make sure we characterize how that’s going to affect the interior of the capsule,” NASA flight director Judd Frieling told reporters last week.
A flotilla of recovery vehicles — including boats, a helicopter, and a U.S. Navy ship called the USS Portland — wait nearby.
The spacecraft was traveling about 32 times the speed of sound (24,850 miles per hour or nearly 40,000 kilometers per hour) when it hit the air — so fast that compression waves caused the exterior of the vehicle to warm to about 5,000 degrees Fahrenheit (2,760 degrees ). Celsius).
“The next big test is the heat shield,” Nelson had told CNN in a telephone interview Thursday, referring to the barrier designed to protect the Orion capsule from the excruciating physics of re-entering Earth’s atmosphere.
The extreme heat also caused air molecules to ionize, creating a buildup of plasma that caused a 5½ minute communications outage, according to Artemis I flight director Judd Frieling.
INTERACTIVE: Trace the path Artemis will take around the moon and back
As the capsule reached about 200,000 feet (61,000 meters) above the Earth’s surface, it performed a roll maneuver that briefly sent the capsule back up — a bit like skipping a rock across the surface of a lake.
There are a number of reasons to use the skip maneuver.
“Skip entry gives us a consistent landing site that supports astronaut safety because it allows teams on the ground to coordinate recovery efforts better and faster,” Joe Bomba, Lockheed Martin’s Orion aerosciences aerothermal lead, said in a statement. Lockheed is NASA’s prime contractor for the Orion spacecraft.
“By dividing the heat and force of reentry into two events, skipping entry also offers benefits, such as reducing the g-forces astronauts are subjected to,” said Lockheed, referring to the crushing forces humans experience during spaceflight.
Another communication blackout of approximately three minutes followed the skip maneuver.
As it began its final descent, the capsule slowed dramatically, losing speed thousands of miles per hour until its parachutes deployed. By the time it splashed down, Orion was traveling about 20 miles per hour (32 kilometers per hour).
While there were no astronauts on this test mission — just a few mannequins equipped to collect data and a Snoopy doll — Nelson, the NASA chief, has emphasized the importance of demonstrating that the capsule can return safely.
The space agency’s plans are to merge the Artemis lunar missions into a program that will send astronauts to Mars, a journey that will have a much faster and bolder return process.
Orion traveled about 1.3 million miles (2 million kilometers) on this mission on a path that swerved to distant lunar orbit, carrying the capsule farther than any spacecraft designed to carry humans has ever traveled.
A secondary goal of this mission was for Orion’s service module, a cylindrical attachment to the underside of the spacecraft, to deploy 10 small satellites. But at least four of those satellites failed after being thrown into orbit, including a miniature lunar lander developed in Japan and one of NASA’s own payload that was intended to be one of the first small satellites to explore interplanetary space.
During its journey, the spacecraft captured stunning images of Earth and, during two close flybys, images of the lunar surface and a mesmerizing “Earth Rise.”
Nelson said if he had to give the Artemis I mission a letter so far, it would be an A.
“No A-plus, simply because we expect things to go wrong. And the good news is that if they go wrong, NASA knows how to fix them,” Nelson said. But “if I have a teacher, I would give it an ten.”
With the success of the Artemis I mission, NASA will now dive into the data collected on this flight and look at choosing a crew for the Artemis II mission, which could launch in 2024.
Artemis II will aim to send astronauts on a similar trajectory to Artemis I, flying around the moon but not landing on the surface.
The Artemis III mission, currently scheduled for a 2025 launch, is expected to put boots back on the moon, and NASA officials have said it will be the first woman and first person of color to reach such a milestone.