The Orion spacecraft may weigh 25 tons, but in a few days it will skip like a small pebble across a pond before plummeting thousands of feet through the air to its target in the Pacific Ocean.
The capsule has begun to say goodbye to the moon, with just one more space flyby scheduled for Monday, Dec. 5, before returning home. NASA has already deployed a crew to San Diego, California to join the Navy at sea for training exercises to prepare for their unprecedented return.
NASA plans to bring Orion back with a so-called “jump entry” into Earth’s atmosphere. It will be the first time the US space agency has tested the technique with a passenger spacecraft. The maneuver involves the lunar ship traveling at an unfathomably high speed and enduring scorching temperatures.
“Orion will come home faster and hotter than any spacecraft before,” NASA Administrator Bill Nelson told reporters in August. “It will hit the Earth’s atmosphere at 32 times the speed of sound, sink into the atmosphere and bleed off some of that speed, before it starts to descend through the atmosphere.”
Orion’s re-entry into Earth’s atmosphere will experience temperatures that will reach 5,000 degrees Fahrenheit. Credit: NASA
Mission leaders say the advantage is breaking the intense G-force loads (the feeling of force that pushes a body during extreme acceleration) into two smaller events rather than one severe episode. Although the capsule is now unmanned, NASA believes that mastering the jump entry will keep Artemis astronauts who would experience these effects safer in the future. When humans are subjected to forces far greater than normal gravity, their hearts are put under tremendous stress, causing dizziness and sometimes shutting down.
But when the capsule returns in a week on December 11, NASA will have to prove that Orion can actually survive the test. Re-entry into Earth’s atmosphere will be a nail-biting finale to Artemis’ 25-day maiden spaceflight, with success dependent on the new heat shield built by Lockheed Martin. The hardware it protects will have to withstand up to 5,000 degrees Fahrenheit, according to NASA.
Imagine a hell half the temperature of the sun’s surface.
“That heat shield on the back is going to show us how we’ve taken this material from the Apollo days and brought it into the 21st century,” Kelly DeFazio, Lockheed’s Orion production manager, said in August . NASA hopes to put astronauts on Orion as soon as 2024 to orbit the Moon. The first landing on the lunar surface would occur on Artemis III, possibly a year later.
The ultimate goal of the Artemis I mission will be a test of the heat shield during re-entry into the Earth’s atmosphere. Credit: NASA
SEE ALSO: NASA is back in the Moon business. That’s what it means.
When Orion plunges toward Earth, it will be traveling at 24,500 mph. By comparison, the space shuttle’s descent reached about 17,500 mph, Nelson said. This initial dive into the upper air will use the atmosphere to slow the capsule down to about 300 mph. It will then re-enter for a final descent, slowing down further with parachutes.
By the time Orion hits the water, it should be doing 20 mph. NASA will have live coverage of the event starting at 11 a.m. ET, with the fall around 12:40 p.m. on Dec. 11.
“Orion will return home faster and hotter than any spacecraft before it.”
The idea of a jump entry has existed on paper since NASA’s Apollo days half a century ago, but was never attempted. At the time, spacecraft didn’t have the navigation systems or the computing power to run it.
“Apollo was just a strictly direct entry, so pretty much your landing site was established before, when you left the moon, with only a small amount of adaptability,” said Chris Edelen, deputy director of ‘integration of Orion,’ to Mashable during a briefing. Wednesday.
Want more science and technology news straight to your inbox? Subscribe to Mashable’s Top Stories newsletter today.
NASA astronaut Alan Bean emerges from the Apollo 12 spacecraft after splashing into the ocean in August 1969. Credit: NASA
For the Apollo missions, the spacecraft plunged into Earth’s atmosphere and then was allowed to travel up to 1,725 miles horizontally before plunging into the ocean. According to the US space agency, a swarm of ships and rafts scattered at sea were waiting on standby for the recovery operation because of such a wide range of possible places that it could fall.
But during a jump entry, Orion should be able to fly more than 5,500 miles beyond the point at which it initially enters the upper air, giving the capsule more control over where it eventually splashes. NASA gets this extra wiggle room by bouncing out of the atmosphere, where there is little drag on the spacecraft.
“One of the major advances of Artemis is that the spacecraft has the ability … to head up and out of a denser part of the atmosphere, glide lower or lower, so you can choose the best landing spot,” Edelen. said
The US Navy and NASA will work together to recover the Orion spacecraft from Artemis I after it splashes into the Pacific Ocean on December 11, 2022. Credit: NASA / Tony Gray
Orion is expected to come back to Earth about 50 miles off the coast of San Diego, California. Credit: NASA/Kim Shiflett
The goal is to launch Orion into water closer to the U.S. coast, allowing crews to exhaust returning astronauts more quickly and reduce the number of boats, helicopters and divers needed to do the job.
Most of the Apollo moon missions concluded with re-entries into Earth’s atmosphere that put the astronauts through the wringer of 6G, or six times the normal force of gravity. Apollo 16, the penultimate manned lunar mission, had the highest G level, tipping just over 7G.
Tweet may have been deleted (opens in a new tab)
If all goes according to plan, Orion’s three test dummies, Commander Moonikin Campos, Helga, and Zohar, will face two rounds of 4G-level forces. That’s a bit more intense than what carnival-goers might experience on a spinning Gravitron, the super-fast centrifugal ride that pins people against the wall with about 3.2 times the normal force of gravity.
Perhaps it is a blessing that the two female mannequins are not wearing helmets. As limbless torsos, they would have a hard time hanging on to the hat.