by 50 years ago today, humans set foot on the Moon for the last time during NASA’s tenure. Apollo 17 mission. And now, after a 1.4 million-mile journey, NASA’s Orion spacecraft has returned safely to Earth; This marks the completion of the agency’s Artemis I mission and the first step towards returning humans to the moon.
“Artemis paves the way for living and working in deep space, in a hostile environment – to invent, create, and ultimately go to Mars with humans,” NASA Administrator Bill Nelson told reporters about two weeks before the leap.
Launched in the early hours of November 16, Artemis I is the first flight test of NASA’s massive Space Launch System (SLS) rocket and the first lunar raid of the agency’s crew-grade Orion spacecraft. During its 26-day mission, Orion followed a record-breaking path around the moon, looping within 80 miles of the lunar surface and flying to a point beyond the Moon at its farthest point, about 270,000 miles from Earth. NASA administrators have tested the spacecraft and challenged it to remain operational in the hostile environment of deep space for much longer than a typical crewed mission would. They tested the propulsion, communication, life support and navigation systems and found no major issues.
“It was an incredible success, and as far as we know, the issues raised were really minor,” says space historian and space historian Teasel Muir-Harmony, curator of the Apollo collection at the National Air and Space Museum. “With a new launch vehicle and a really complex mission, it’s exciting to see it working so well.”
The most important—and dangerous—test took place today, when Orion left space and returned to Earth at high speed. Traveling at about 25,000 miles per hour, the spacecraft performed what is called jump reentry, briefly entering and exiting the outskirts of the atmosphere to reduce its speed before making a second, final dive. The next time Orion touched Earth’s air, instead of floating through the atmosphere like a bouncing stone, he plunged all the way. As the spacecraft descended, atmospheric friction heated its exterior to 5,000 degrees Fahrenheit, or roughly half the sun’s surface.
“They’re basically going through a blowtorch,” says Daniel Dumbacher, who oversaw the initial development of SLS while at NASA and now serves as executive director of the American Institute of Aeronautics and Astronautics. “We will never, ever be comfortable and complacent about re-entry. Re-entry is a high-risk, high-energy [maneuver]; You want to make sure you understand correctly.”
Surviving this dive without burning required the spacecraft’s heat shield to function perfectly, and it did. Next up were the drogue and main aircraft parachutes, which activated when the capsule was 5,300 feet above the Pacific Ocean, reducing its speed to just 20 miles per hour.
At 12:40 PM ET, Orion was dangling safely like an oversized, billion-dollar mushroom among the white sheets off Guadalupe Island, waiting to be rescued by a contingent of NASA and US Navy personnel.
A Smooth Jerky Journey
Just after 1:45 AM ET on November 16, NASA’s orange SLS rocket roared and shone into the sky, illuminating Florida’s Space Beach in an artificial dawn. The launch was a triumph: It was the largest rocket ever sent by humans into space, and for the first time in half a century, a crew-grade spacecraft would visit the lunar periphery. These milestones came after years of delays in development and testing where costs skyrocketed. And they followed months of inactivity on the launch pad after leaks during refueling obliterated previous flight attempts and multiple hurricanes erupted, one of which hit the SLS-and-Orion “stack” with heavy rain and storms at 100 miles per hour.
However, after this difficult exit, the road improved. SLS placed Orion in orbit perfectly. The spacecraft entered a course towards the moon, perfectly performing a crucial 20-minute engine burn. The engines remained accurate while flying, firing multiple times to enter and exit lunar orbit and then return home. Along the way, mission managers did not detect any major anomalies on the ship, just a series of minor incidents that they called “funny”—something that was unexpected but not exactly a problem.
“The surprises we’ve had are pleasant surprises,” NASA’s Artemis mission manager Mike Sarafin said at a press conference on Nov. and meets or exceeds expectations across the board.
Perhaps the most serious problem during the mission occurred on the ground on the first weekend of December, when NASA’s Goldstone radio telescope, the backbone of the Deep Space Network, went offline and blocked communication with the spacecraft for several hours. The launch facility at Kennedy Space Center also suffered some unexpected damage as the SLS launched off the ramp, as shock waves and exhaust fumes battered the mobile launch structure and blew the doors of the elevators.
In fact, things progressed so quickly that as the mission progressed, managers were confident enough to conduct additional, in-flight tests of the spacecraft’s capability. And in the end, it all worked.
“We get exactly what we need from this, it’s a convoluted journey to make sure the systems are all working,” Dumbacher says. “The fact that it’s working so well tells us we have a system ready to use, and I’m guessing they will conclude that it will be safe to put people in the next system.”
Problematic Loads
While Artemis I achieved its primary goals of demonstrating Orion’s ability in deep space and successfully returning the spacecraft to Earth, some of the mission’s secondary missions produced decidedly mixed results. When the spacecraft was launched into orbit, it carried 10 CubeSats or shoebox-sized science experiments. Some of these were aimed at studying ice and other features on the Moon’s surface. Others were sent to monitor the space environment. One, NASA’s NEA Scout, has even been targeted to rendezvous with a near-Earth asteroid.
About half of these 10 CubeSats worked as planned. It’s not clear whether the problems with the others are related to the long stay of the experiments on the rocket – these were loaded into the SLS more than a year ago and some were deployed without fully charged batteries – or with a minor design challenge. satellite to work in deep space.
The NEA Scout is presumed lost as it has not yet made contact with the ground; The team doesn’t even know if the spacecraft is operational. A Japanese CubeSat, OMOTENASHI, was intended to send a small lander to the lunar surface, but once deployed, it spiraled out of control, preventing further operations. LunaH-Map, another NASA CubeSat, failed to perform a crucial thrust maneuver and is now unable to complete its goal of mapping ice deposits around the moon’s south pole.
“They all go into deep space, which isn’t a traditional environment for CubeSats—it’s more challenging,” says Paulo Lozano of the Massachusetts Institute of Technology, who builds propulsion systems for small satellites. Lozano says he’s really impressed with how well CubeSats perform overall, describing the tasks where they had the biggest problems as “ambitious.”
“There’s not a lot of opportunity to go deep into space with CubeSats, so I think having more of these opportunities is a great thing for small satellites,” Lozano says. “I think there will be a lot to learn about how to design these spacecraft so that in the future we can design small spacecraft that can accomplish what large spacecraft can do.”
“Earth” Again
Despite these hiccups, Artemis I far outperformed her equivalent mission during the Apollo program: 1968’s Apollo 6The last nearly unsuccessful unmanned test flight of the Saturn V rocket and the Apollo spacecraft.
“It didn’t fulfill its mission profile. There were big problems with it. [engine] oscillations during launch. There were engine failures – the engines turned off early. could not go to the moon; “It was supposed to stay in Earth orbit,” says Muir-Harmony. “These were some pretty significant issues that came up on that mission. But they got data. They were able to analyze the mission. They felt like they could move on to the next mission.”
even as Apollo 6 He limped across the finish line, NASA chose to put people on board Apollo 7, It lays the groundwork for subsequent missions that orbit the Earth for 10 days and deliver astronauts to lunar orbit and then to the lunar surface.
“I’d be surprised – if this mission had gone like this Apollo 6“We wouldn’t have done another test mission, but that’s hard to say,” Muir-Harmony says. “We now have decades of spaceflight experience. This is very different from what it would have been in the 1960s, when we had almost no spaceflight experience.”
Maybe it fits the day after half a century Apollo 17 Landing on a mountain range along the southeastern edge of the lunar region of the Mare Serenitatis, Orion returned to Earth in much the same way as in ancient puddles. before reaching the moon, Apollo 17 The crew captured an image of Earth, a swirling, sandy-blue marble, ink glowing against nothingness, that has become one of our planet’s most recognizable depictions. Orion also captured cosmic images during his journey and sent home a series of spectacular images. in a seriesA crescent Earth shines above the monochrome lunar horizon as Orion turns the moon’s curve and appears in the foreground – a homage Apollo 8“Earthrise” for the Artemis generation.
December 14 will celebrate its 50th anniversary. Apollo 17NASA astronaut Eugene Cernan becomes the last person to ever walk on the moon, after luring several hundred pounds of moon rocks to his spacecraft. Although Cernan knew as he left that the moon would once again return to desolate solitude, he could not have foreseen at that time that it would take decades for people to return.
“I’m on the surface. And as I take the last human step from the surface, returning home for a while – but we don’t believe in a very long future – just [say] What I believe history will record,” Cernan said, “America’s challenge today has shaped the destiny of the people of tomorrow.”
