NASA’s Artemis I mission returned to Earth on Sunday, concluding a 25½-day journey viewed as an essential precursor to human trips to the moon.
The splashdown and retrieval of the uncrewed Orion capsule off Mexico’s Baja coast was the final step in a dry run of the U.S. space agency’s new heavy launch system and the maiden flight of a spacecraft designed to ferry astronauts into lunar orbit.
The incoming spacecraft hit the atmosphere while travelling at about 40,000 kilometres an hour, providing a crucial test of its protective heat shield. The shield, made of heat-absorbing ceramic tiles, was projected to reach temperatures of around 2,800 degrees Celsius during its searing re-entry – roughly double that experienced by capsules returning from the International Space Station.
Orion experienced two separate episodes of extreme heat as part of a “skip re-entry manoeuvre,” which caused it to skip off the upper atmosphere like a stone skipping off water, before its final descent in order to facilitate deceleration.
Once it shed enough velocity, the capsule deployed parachutes and was spotted by cameras drifting downward toward the Pacific in fair weather, hitting the water with a visible splash at 9:40 a.m. local time.
“This is what mission success looks like,” said mission manager Mike Sarafin at a news briefing after the splashdown. “There are more complex and more challenging missions up ahead, but we’ve got a foundational capability here.”
NASA officials were not the only ones elated by the safe arrival of their spacecraft.
In a statement, Canadian Space Agency president Lisa Campbell said Artemis I “has laid a vital foundation for the future of human exploration into deep space.”
The next time an Orion capsule re-enters the atmosphere it is expected to be carrying the first Canadian, among others, to fly around the moon, as part of the Artemis II mission, currently set for launch no earlier than May, 2024.
Within minutes of the capsule’s safe arrival, Canadian astronaut Jeremy Hansen, who is among that trip’s candidates, posted a tweet that simply said, “Yes!!!!!” alongside video of the splashdown.
Artemis I was launched on Nov. 15 after multiple delays due to technical issues and weather. Once in flight, the mission appeared to proceed with few hitches. At one point, its long looping trajectory brought it within 130 kilometres of the lunar surface. On Nov. 25, Orion reached a distance of more than 430,000 kilometres from Earth, the greatest distance recorded by a spacecraft rated for human travel.
In total, the capsule travelled more than two million kilometres from launch to splashdown. Its return coincided with the 50th anniversary of the last Apollo moon landing on December 11, 1972. The next moon landing is the goal of the Artemis III mission, which NASA has slated for launch as soon as 2025.
But while the performance of Artemis I helps speed NASA toward that objective, it is unlikely to allay critics who warn that the program is too expensive to make lunar exploration sustainable in the long term. The U.S. government pegs the cost at more than US$4-billion a launch.
In a memoir published this year, Lori Garver, a former NASA deputy administrator, called the agency’s approach an outdated one that overpromises on what it can deliver. During her time at the agency, she championed the role of private companies such as SpaceX in reducing the cost of spaceflight.
Roger Launius, an American space historian and chronicler of the Apollo program of the 1960s and 70s, said that Ms. Garver has a point.
During the lead up to the moon landings, when the U.S. was vying with the Soviet Union to put the first astronauts on the moon, NASA absorbed nearly 4.5 per cent of the total annual U.S. federal budget at its peak. In more recent years, its share of the budget has consistently been close to 0.5 per cent.
To surpass what was done during the Apollo era, Dr. Launius said the space agency will need to collaborate wisely with its international partners and a commercially motivated private sector to create an enduring presence on the moon for an acceptable price.
“If it’s just a one-off thing and we declare victory and walk away then it’s probably not worth doing,” he said. “If we can create an infrastructure that will enable us to do things on the moon – and fashion it so that it’ll fit within the budget profile – then I think we’re going to see some really great things.”
Dr. Launius said such a vision would include a lunar habitat that is occupied on a permanent or semi-permanent basis, much like Antarctic research stations are today.
Another element in development is the Gateway, a small space station about 30 metres long, which would serve as a transfer point for astronauts and equipment arriving from Earth and heading to various points of interest on the lunar surface.
The aerospace company MDA is developing two Canadian robot arms for the Gateway, which it will operate at a new facility now under construction in Brampton, Ont. Last March the company was awarded $269-million from the Canadian Space Agency, which officially became a partner in the Gateway in 2019.
Richard Rembala, a systems engineer and chief architect of the project at MDA, said that seeing Artemis I in flight brings a heightened sense of momentum to the effort.
“You know the train has really left the station,” he said. “Now we have to do our part.”
MDA’s vice-president of robotics and space operations, Holly Johnson, said that the project is generating interest from customers looking to expand their space operations with robots that can be directed from Earth.
“They’re looking for high reliability, low-risk solutions that really make their missions successful,” she said. “Robotics is an enabler of that.”
Artemis I is the first step toward an ongoing human presence on the moon. The ambitious international program using NASA’s most powerful rocket ever, aims to send two test flights to the moon before the first human landing since the Apollo missions.
The Globe and Mail