Weapons enthusiasts have been experimenting with 3D-printed guns for months, with mixed results. But NASA has set its sights much higher – quite literally – having successfully tested 3D-printed parts under the torturous conditions of rocket engines.
The most recent such test took place on August 22, the space agency revealed on Tuesday, and the one-off component in question reportedly withstood a record-setting 20,000 pounds of thrust.
The part tested was an injector, a component that provides liquid oxygen and gaseous hydrogen to the rocket engine's combustion chamber. Similar in design to the injectors found in the RS-25 engines that will power NASA's Space Launch System (SLS) rocket, the version used in the test produced 10 times more thrust than previous 3D-printed models.
NASA isn't planning to send 3D-printed parts into orbit any time soon, but its recent successful tests prove that 3D printing technology can be a valuable asset for space engineering, even for components that must survive incredible forces.
"This entire effort helped us learn what it takes to build larger 3D parts – from design, to manufacturing, to testing," Greg Barnett, lead engineer for the project, said in a statement. "This technology can be applied to any of SLS's engines, or to rocket components being built by private industry."
Naturally, NASA isn't using just any 3D printer to pull this off. It hired Austin, Texas–based Directed Manufacturing to fabricate the injector using a printer that employs selective laser melting to fuse layer after layer of nickel-chromium alloy.
Such additive metal-based printers cost tens or hundreds of thousands of dollars – well out of the price range of all but the most rabidly dedicated hobbyists. By comparison, the "Liberator" 3D-printed pistol that has been in the news is fabricated from simple plastic.
NASA also credits its success to the unique, simplified injector design used in its latest 3D printing tests. The first injector design it tested comprised 115 parts; the one tested last week consisted of only two.
Because of the latest design's similarity to existing components, however, the space agency will be able to directly compare the 3D-printed injector's performance to that of injectors manufactured by traditional means.
So far, NASA says, the 3D-printed part seems to have worked "flawlessly," despite being subjected to 1,400 pounds per square inch of pressure at nearly 6,000° Fahrenheit (3,316° C), though it will take more study to determine whether 3D-printed components have what it takes to be used in actual missions. To that end, scientists plan to examine the fired injector more closely using computer scans and other techniques in the coming days. ®