The tiles designed to prevent the Space Shuttle from burning up are not up to the task of protecting Orion, the new spacecraft that will replace the Shuttle in just a few years.
Blasting through the atmosphere at 5 miles per second, the Space Shuttle gets pretty hot. But things will be different for theits replacement: The Orion crew module. It must return from the moon, too, going much faster, and getting five to six times as hot.
"Inside NASA's Arc Jet chamber, a sample of material is mounted directly in the path of an extremely hot blast of air. What comes out of here is hotter than the surface of the sun. And it's the best thing we have on Earth to simulate what happens to a space craft on its way back down to Earth."
James Reuther, Project Manager for Thermal Protection of Orion, says, "There's no other facility that we have anywhere in the world that could simulate those kinds of conditions. There's a lot of pressure to make sure that we get this right, and there are no mistakes in our design."
Reuther leads the team responsible for selecting the best possible material. After 2 years, they've narrowed a field of six down to two One of the two is a surprise: AVCOAT, the same technology developed for the Apollo moon modules 40 years ago. It still works well.
The other is PICA, a new composite of Phenol Impregnated Carbon Ablator.
The "ablator" reference means that part of it intentionally burns away, or ablates.
"Without it," says Reuther, "the vehicle would burn up in a matter of seconds."
The new ablator was a hit on its first mission, the Stardust probe that performed the first comet biopsy. It won the space agency's Invention of the Year award, for its three developers. One of the three, Huy Tan, is still amazed the material worked so well.
"I'm most proud," she says, "of being able to send this spacecraft to space for 7 years, collecting a comet, and bringing it back. And it performed beautifully. I mean, it's just incredible."
It's also incredible that it's competing with a technology from the 60s (AVCOAT), to take us to the moon and to Mars. Selecting just one of them brings a lot of pressure, but these teams wouldn't be in the kitchen if they couldn't take it.
Adds Tan, "I say, yeah, we take the heat!"
NASA will decide on the final heat shielding material this coming winter.
------- Links -------
NASA AMES RESEARCH CENTER
ARC Jet Complex
Creates "lightning in a bottle" to support NASA's research and development activities in thermal protection, vehicle structures, aerothermodynamics and hypersonics.
http://tinyurl.com/4m7m6f
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NASA/CONSTELLATION PROGRAM
NASA'S NEW SPACECRAFT
NASA Ames Research Center/Orion Advanced Development Project
NASA plans to send explorers to the moon aboard the Orion crew exploration vehicle, part of the Constellation Program, which includes Mars and other destinations in the solar system.
http://www.nasa.gov/mission_pages/constellation/orion/index.html
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NASA MISSION CALENDAR
http://www.nasa.gov/missions/calendar/index.html
