3D Animations Provide New Insights into Thermal Protection Materials
NASA space exploration vehicles blazing through the atmosphere to return to Earth—or touch down on other planets—are shielded by specially designed and developed thermal protection materials that can withstand temperatures up to 3,000 degrees F.
Researchers at the NASA Advanced Supercomputing (NAS) facility are exploring 3D images and animations of newly developed thermal protection system (TPS) materials being developed in support of future missions. For the first time, 3D complex structures in the TPS fibers are being revealed at the microscale—one-tenth the thickness of a human hair. Scientists Francesco Panerai, NASA visiting scientist from the University of Kentucky, and Nagi N. Mansour, chief of the NAS Division's Fundamental Modeling & Simulation Branch, are collaborating with the Hypersonic Entry, Descent, and Landing team at NASA's Ames Research Center to model, understand, and predict the durability and strength of new materials that will protect future spacecraft heading beyond low Earth orbit to Mars and other space exploration destinations. The work supports NASA's Space Technology Game-Changing Development Program.
"The exciting part is that we can see detailed features of the material that we can't see with the eye or in 2D," said Panerai. "To predict what will happen to the TPS materials under the extreme conditions of entering an atmosphere from space, engineers need to thoroughly know the structure of the materials, and we're curious to find out what we're going to discover."
To create realistic 3D images, NAS visualization expert Tim Sandstrom began with a series of X-ray micro-tomography scans produced by the Advanced Light Source synchrotron at Lawrence Berkeley National Laboratory. Running the image data through a sequence of customized software tools that include NAS's in-house Field Model and the open-source Embree ray-tracing software, Sandstrom transformed the volume of microtomography data into a 3D cube. Scientists can explore this 3D space by zooming through what looks like "a forest of French fries," Sandstrom said.
Ray tracing effects reflect light, shadows, and reflections to get the amazing photo-realistic images seen in blockbuster animated films, and that NAS scientists are using to understand the materials they are exploring.
In March 2015, Panerai presented a paper, "Analysis of Fibrous Felts for Flexible Ablators Using Synchrotron Hard X-Ray Micro-Tomography," at the 8th European Symposium on Aerothermodynamics for Space Vehicles. The authors analyzed the material properties of rigid and flexible fibers to gain insight into how these fibers transport heat and decompose. In this work, microscale imaging was used to compute properties of existing TPS materials such as phenolic impregnated carbon ablator, commonly known as PICA, which NASA developed and successfully used on both the Stardust capsule and the Mars Science Lab.
— Jill Dunbar, NASA Ames Research Center
