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In a bit more than a year and a half we may all be sitting on the edge of our seats, watching Americans return to the surface of the Moon. NASA just talked about what it learned from its first test flight around the Moon with its new capsule. Engineers are scratching their heads about the heat shield.
The top priority of this first mission was to make sure the heat shield would protect a crew on the fast, hot return from the Moon. NASA executives just told reporters about all the successes they had on this mission. But, they said the heat shield did not act the way they expected.
TOP PRIORITY
The shield is critical to the mission. If it doesn’t work, NASA would never launch astronauts. They need to get them back to Earth safely. Before the Artemis 1 mission, I wrote a bit about the heat shields and the people that have poured their lives into the technology to make sure the astronauts are safe.
There was confidence the heat shield would work. It did. But it didn’t act in the way NASA expected and that is not good in the world of the engineers at the US space agency. When your tests and models on Earth say the shield should do this, or that, and it doesn’t, it is a concern.
Howard Hu, who heads the Orion Capsule program for NASA, told reporters, “there were more variations across the heat shield than we expected.” He called it a “phenomenon” that Orion experienced on reentry.
BREAKING OFF RATHER THAN BURNING OFF
This heat shield is ablative. That means the protective material is meant to burn off and dissipate the heat as the capsule reenters the Earth’s atmosphere. Something strange happened on reentry. The material was burning and charring, but more than expected was being “liberated.” The material that protects Orion is called AVCOAT. It is supposed to burn and char. But more of that char was breaking away from the heat shield.
“Some of it we're seeing, is larger like more of little pieces, that would come off rather than being ablated. And I think that's one of the things that was a little bit unexpected,” Hu said. The software and mathematical models used before flight didn’t show so much of the charred material breaking off. Plenty of what Hu called, “virgin AVCOAT,” remained on the heat shield, “and that’s good.”
DIDN’T MATCH THE MODELS
Now, NASA is looking at video, photos, and all the data it collected on this most important part of hardware. “We do have a dedicated investigation going on with detailed analysis. We have extracted some samples from the heat shield, which we're doing X-rays against,” Hu said.
“We're scratching our heads a little bit relative to, ‘Hey, how did our models or test program not pick this up?,’” Hu said after explaining the material braking off.
“I would say I'm being very cautious… Vigilance is very important for us and the flight crew going forward,” Hu added.
CREWED FLIGHT- NOVEMBER 2024?
The crew flight is next. You will have to wait more than a year and a half. NASA is building the Artemis 2 rocket and new Orion capsule now. Artemis 2 will orbit, but not land on the Moon. That will be left to Artemis 3 at least a year later in the last part of 2025. NASA is already saying these dates can slide because a lot has to happen between now and launch.
In order for this new lunar visit, NASA will need a lander. That is the SpaceX Starship. It has not flown nor been certified for human flight. NASA also needs new spacesuits for the astronauts to use on the lunar surface.
NASA first needs to be convinced its heat shield will protect the astronauts coming home. It looks like it will as long as engineers learn why the heat shield didn’t act and perform as expected.
Great piece! You have any idea what kind of guts the humans must have to climb in atop those space ships and take that ride? Talk about sitting in the hot seat. (Pun intended.) I so look forward to being a person who was alive to see our first Lunar landing and now, with a little luck, to be alive to see our next step into outer space. Just WOW!