() — The Artemis I mission, a 25 1/2-day unmanned test flight around the Moon intended to pave the way for future astronaut missions, came to an end, following the splashdown of NASA’s Orion spacecraft in the ocean. this Sunday.
The spacecraft finished the final leg of its journey, approaching the thick inner layer of Earth’s atmosphere after traversing 239,000 miles (385,000 kilometers) between the Moon and Earth. It splashed down at 12:40 pm ET this Sunday in the Pacific Ocean off Baja California, Mexico.
The Orion capsule was scheduled to splash down near San Diego, but NASA officials said Thursday that rain, wind and large waves had moved into that area and it no longer met the space agency’s weather criteria.
Rob Navias, the NASA commentator who led Sunday’s broadcast, called reentry a “playbook” process.
The Orion capsule, with its three main parachutes deployed, approaches the ocean surface. Credit: NASA/Youtube
This final step was one of the most important and dangerous stages of the mission.
“We are not out of the woods yet. The next big test is the heat shield,” NASA Administrator Bill Nelson told in a phone interview Thursday, referring to the barrier designed to protect the Orion capsule from the unbearable physics of re-entering the Earth. terrestrial atmosphere.
The spacecraft was traveling at 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 the compression waves caused the exterior of the vehicle to heat up to about 5,000 degrees Fahrenheit ( 2,760 degrees Celsius). The extreme heat also caused air molecules to ionize, creating a buildup of plasma that caused an expected blackout, according to Artemis I flight director Judd Frieling.
As the capsule reaches about 200,000 miles (322,000 kilometers) above Earth’s surface, it will perform a roll maneuver that will send it briefly upward, much like skipping a rock across the surface of a lake.
There are a couple of reasons to try the jump maneuver.
“Jumping the gate gives us a consistent landing site that supports astronaut safety by allowing teams on the ground to better and faster coordinate recovery efforts,” said Joe Bomba, Lockheed Martin aeroscience aerothermal lead at Orion, in a release. Lockheed is NASA’s prime contractor for the Orion spacecraft.
“By splitting the heat and force of re-entry into two events, jump-in also offers benefits such as decreasing the G-forces that astronauts are subjected to,” according to Lockheed, referring to the crushing forces humans experience during space flights.
As it embarked on its final descent, the capsule slowed dramatically, losing thousands of miles per hour until its parachutes deployed. Orion fell at 20 miles per hour (32 kilometers per hour).
While there are no astronauts on this test mission — just a few dummies equipped to collect data and a Snoopy doll — NASA chief Nelson has stressed the importance of demonstrating that the capsule can return safely.
The space agency’s plans are to turn the Artemis lunar missions into a program that will send astronauts to Mars, a journey that will have a much faster and bolder re-entry process.
The Orion capsule captures a view of the lunar surface, with Earth in the background illuminated in a crescent shape by the sun. (Credit: NASA)
Upon returning from this mission, Orion will have traveled approximately 1.3 million miles (2 million kilometers) on a looping path toward a distant lunar orbit, taking the capsule farther than any spacecraft designed to carry it has ever traveled. humans.
A secondary goal of this mission was for the Orion Service Module, a cylindrical accessory at the bottom of the spacecraft, to deploy 10 small satellites. But at least four of those satellites have failed after being launched into orbit, including a miniature lunar lander developed in Japan and one of the NASA’s own payloads that it was destined to be one of the first small satellites to explore interplanetary space.
On its journey, the spacecraft captured stunning images of Earth and, during two close flybys, images of the lunar surface and a fascinating “Earth rise.”
Nelson said that if he had to give the Artemis I mission a letter grade so far, it would be an A.
“Not an A-plus, simply because we expect things to go wrong. And the good news is that when they go wrong, NASA knows how to fix them,” Nelson said. But “if he were a schoolteacher, I’d give him an A-plus.”
If the Artemis I mission is successful, NASA will dive into the data collected on this flight and look to pick a crew for the Artemis II mission, which could take off in 2024.
Artemis II will aim to send astronauts on a similar trajectory to Artemis I, flying around the moon but not landing on its surface.
The Artemis III mission, currently scheduled for a 2025 releaseset foot on the Moon again, and NASA officials have said it will include the first woman and first person of color to achieve such a milestone.
