When it comes to finding the best new materials for building rockets, NASA has an old-fashioned approach: apply pressure and see what breaks first. In the video above, you can see the space agency testing 8.4-foot-tall barrels made of (are you ready?) graphite-epoxy honeycomb-core sandwich composites. The barrels were rigged with a network of 300 electronic strain sensors and 16,000 fiber optics sensors to measure their structural integrity during the process, and even the polka dots are part of the test — they make it easier to measure movement and deformation using high-speed cameras.
The barrels in the video are being squeezed with loads of 900,000 pounds
The material being tested in the video could one day be used for building launch-vehicle structures — aka rockets and boosters. NASA says that these sorts of composite materials can have many benefits over traditional metals, including "lower mass, better fatigue resistance, lower part count, and reduced life-cycle cost." But, of course, they need to be tested to make sure they can withstand the terrific pressures of a space launch.
The barrels in the video above are being squeezed with compressive loads of almost 900,000 pounds — equivalent to the weight of around 60 full-grown elephants. NASA's engineers say they were able to predict when the barrels would break to within an accuracy of 1 percent, but were still surprised when the breaking point arrived. "All eyes were on the test article and, even though we were expecting it, the failure still caught us off guard," said research engineer Marc Schultz. "The loud bang first startled us and then we saw the crack all the way around the barrel that formed almost instantaneously from the buckling event." We're not surprised — the sound of the barrels cracking is like a massive bell tolling. It must have been quite impressive to hear it in person.