The capsule that carried Apollo 11 astronauts safely back to Earth in 1969 used a heat shield made of epoxy resin to protect its contents from the 5,000-degree heat of reentry. The resin, called Avcoat, was designed to erode, carrying heat away from the surface. A half century later, NASA’s Orion spacecraft uses the same material. Brian Hinde, Lockheed Martin’s Orion Structures and Aeroshell Senior Manager, says that the most important innovation for heat shield technology isn’t finding new materials, but increasing the efficiency of materials already in use. On the Apollo capsule, the Avcoat was injected into thousands of individual cells of a fiberglass honeycomb, an agonizingly slow process. The tool used was, in essence, “a high-pressure caulk gun,” says Hinde.
For Orion, the caulk gun at least is gone. Now the resin is produced in billets. “Then we very efficiently model and 3D machine very accurately—by keeping everything in the computer—the exact shape of the tiles we want and bond them on,” he says. The new process saves time and weight. Matt Gasch of NASA Ames Research Center puts into perspective the reliance on trusted materials. Heat shields are a “single point of failure,” he says. “They either work or they don’t.”
This edition of A+S NEXT was published in cooperation with Florida International University’s College of Communication, Architecture + The Arts (CARTA).
Gabriel Munoz is an FIU senior majoring in journalism and religious studies. He hopes to communicate advancements in technology and bridge the gap between scientists and the general public.