Suspended under parachutes, an astronaut capsule without astronauts made a gentle splash in the Pacific on Sunday, bringing NASA’s Artemis I moon mission to a close.
The end of the uncrewed test flight coincided with the 50th anniversary of the landing of Apollo 17 on the moon, the last time that NASA astronauts walked there.
The Artemis program is the successor to Apollo, and after years of delays and a mounting price tag, the new rocket and spacecraft that will take astronauts back to the moon worked about as smoothly as mission managers could have hoped.
“A new day has dawned, and the Artemis generation is taking us there,” Bill Nelson, the NASA administrator, said on NASA Television after the splashdown.
The moon trip capped a year of spectacular successes for NASA. Its James Webb Space Telescope, which launched almost a year ago, began sending back breathtaking images of the cosmos this summer. Its DART mission showed in September that slamming into an asteroid on purpose could protect Earth in the future if a deadly space rock is discovered on a collision course with our planet.
With the conclusion of Artemis I, more attention will shift toward SpaceX, the private rocket company founded by Elon Musk. NASA is relying on a version of Starship, the company’s next-generation spacecraft that has not yet flown to space, to land astronauts on the moon.
On Sunday, just after noon Eastern time, the Orion crew capsule — where astronauts will sit during future flights — re-entered the Earth’s atmosphere at 24,500 miles per hour. This was the mission’s last major objective: to demonstrate that the capsule’s heat shield could withstand the temperatures up to 5,000 degrees Fahrenheit.
By design, the capsule bounced off the upper layer of air before re-entering a second time. It was the first time that a capsule designed for astronauts had performed this maneuver, known as a skip-entry, which enables more precise steering toward the landing site. As expected, there were two blackouts in communications as the heat from the encounter with the atmosphere created electrically charged gases around the capsule that blocked the radio signals.
Before and after the blackouts, live video from outside Orion’s window showed impressive views of Earth getting larger and larger.
At 12:40 p.m. Eastern time, the capsule settled in the Pacific Ocean off Mexico’s Baja peninsula. Ship recovery crews aboard the U.S.S. Portland encountered brisk winds and choppy seas with waves four to five feet high.
Over the next few hours, recovery crews are working to pull Orion out of the water. It will be headed back to NASA’s Kennedy Space Center in Florida for inspection.
The capsule and the Space Launch System, a giant new rocket, are key pieces of Artemis, which aims to land astronauts on the moon near its south pole as early as 2025.
“If you asked me to grade it, I’d give us an A+,” Catherine Koerner, the deputy associate administrator for exploration systems development at NASA, said on NASA Television as Orion approached Earth Sunday morning. “We’ve been learning how the spacecraft operates, and we’ve been learning how to fly this amazing machine.”
During the 26 days of Artemis I, glitches popped up as expected, but the flight appeared to be devoid of major malfunctions that would require a lengthy investigation and redesign.
“It’s a great demonstration that this stuff works,” said Daniel L. Dumbacher, the executive director of the American Institute of Aeronautics and Astronautics. Mr. Dumbacher oversaw early work on the Space Launch System more than a decade ago when he was a top human spaceflight official at NASA.
While the mission was years behind schedule and billions of dollars over budget, the flight provided some validation of the traditional government-run approach that NASA took for the development of the complex space hardware.
“From my standpoint, it certainly measures up to the expectations, if not more,” said Jeff Bingham, a former senior Republican aide on the Senate subcommittee that shaped legislation in 2010 directing NASA to build the Space Launch System. “I feel good about the fact that what we intended is coming to fruition.”
Even Lori Garver, a former deputy administrator of NASA who favored turning to private companies to come up with more innovative rocket designs that might have been built faster and cheaper, acknowledged that the Artemis I flight went smoothly.
“It’s fantastic that it is working,” she said. “It’s a huge relief, and excitement, at NASA.”
The space agency now appears to be in good shape to launch the next mission, Artemis II, as planned in 2024. That flight will send four astronauts to the moon, without landing, and then back to Earth.
The moon landing is planned for the third Artemis mission, in which the Space Launch System and Orion will ferry four astronauts to a large looping orbit around the moon. That task will not require capabilities beyond those demonstrated during Artemis I and Artemis II.
Manufacturing the hardware for those missions is already well underway. The Orion capsule for Artemis II is already mostly built at the Kennedy Space Center. The service module for Orion, built by Airbus as part of the European Space Agency’s contributions to the moon missions, was delivered last year. This weekend, the bottom section for the rocket that will launch Artemis III arrived at Kennedy for installation.
But Artemis III will hinge on a third requisite piece: a lander built by SpaceX. And for that part of the mission, Mr. Musk’s company will have to pull off a series of technological marvels that have never been achieved before.
“I think all eyes do start turning to the lander at some point,” said Ms. Garver, whose work during the Obama administration helped lay the foundation for SpaceX’s current program of taking astronauts to the International Space Station.
NASA awarded SpaceX a $2.9 billion contract in 2021 to develop and build the lunar lander, which is a variation of the giant Starship rocket, for Artemis III.
A long-promised test launch of Starship to orbit has yet to occur, although a hubbub of activity at the company’s development site in South Texas indicates that SpaceX is getting closer.
For Artemis III, the lander will dock with the Orion spacecraft above the moon.
Two astronauts will move over to the lander and head to the south polar region of the moon, spending close to a week on the surface.
But getting the lander to lunar orbit will be far from easy.
For one, it will require at least three different Starships. The Starship system is a two-stage rocket: a reusable booster known as the Super Heavy with the Starship spacecraft on top. After reaching orbit, the tanks of the second stage — the Starship spacecraft — will be almost empty, with not enough propellant to head to the moon.
Thus, SpaceX will first launch a Starship that will essentially serve as a gas station in orbit. Then, it will conduct a series of launches — Mr. Musk has said no more than eight will be needed — of a tanker version of Starship to carry propellant to the gas station Starship.
The final launch is to be the lunar lander Starship, which will sidle up to the gas station Starship in orbit and fill up its tanks. The lunar lander will then finally be ready to head to the moon.
While NASA’s Space Launch System rocket flies just once and all of the pieces fall into the ocean as litter, SpaceX’s Starship is designed to be entirely reusable. That will make the launches frequent and cheap, Mr. Musk says.
Before Artemis III, SpaceX is to conduct an uncrewed test first to show that it can indeed perform a quick succession of Starship launches, reliably transfer propellants in orbit and safely land on the moon.
The idea of refueling in space dates back decades but remains largely untested.
“Knowing what I think I know about the state of our research into microgravity propellant transfer, we have a long way to go,” Mr. Dumbacher said.
Rocket launches also remain risky, so the multitude of Starship launches needed for Artemis III raises the chances that one of them fails, scuttling the entire endeavor.
By turning over development of the lunar lander to SpaceX, NASA hopes that the innovative approach of Mr. Musk’s company will provide a lander more quickly at a lower cost than a NASA-led program could.
The flip side is that if SpaceX finds the technical challenges more difficult than expected, NASA will not have an immediate alternative to turn to. The agency just received proposals from other companies for a second lander design, but the second lander design is intended for later moon mission. (In November, NASA awarded SpaceX an additional $1.15 billion to provide the lander for Artemis IV.)
Mr. Musk has also added to his portfolio of companies with the purchase of Twitter, where the turmoil that has followed his takeover of the social media company is now consuming much of his time and attention.
“That is new,” Ms. Garver said. “The Elon concerns have escalated,” although she said she was not sure how much those directly affect work at SpaceX.
CNBC reported last month that SpaceX has shaken up the leadership of its Texas Starship operation with Gwynne Shotwell, SpaceX’s president, and Mark Juncosa, the company’s vice president of vehicle engineering, now overseeing the site.
Last week, Mr. Musk said on Twitter that he continues to oversee both SpaceX and Tesla, his electric car company, “but the teams there are so good that often little is needed from me.”
Mr. Bingham said he hoped for Starship to succeed, but “It’s a lot of uncertainty in there, and it’s worrisome.”
If SpaceX does indeed succeed with Starship, NASA will have financed much of the development of a spacecraft capable of taking astronauts to Mars at the bargain basement price of a lunar lander.