A 3-D printed rocket part blazes to life during a hot-fire test.
Image Credit: NASA/MSFC/David Olive
Things that make you say Hmmm…printing a 20,000 pound thrust rocket motor….hmmm. I am off to Best Buy to get my first 3D printer!!!! The future is really her once we can start printing parts like this at home. IF we can make rocket engines how hard can a new faucet be? In any case NASA tested the largest 3-D printed rocket engine component ever created. Aug. 22 an engine firing test generated a record 20,000 pounds of thrust. They did not build an entire engine but they did make the critical injector. This part delivers propellants to power an engine and provides the thrust necessary to send rockets to space. During the injector test, liquid oxygen and gaseous hydrogen passed through the component into a combustion chamber and produced 10 times more thrust than any injector previously fabricated using 3-D printing.
“This successful test of a 3-D printed rocket injector brings NASA significantly closer to proving this innovative technology can be used to reduce the cost of flight hardware,” said Chris Singer, director of the Engineering Directorate at NASA’s Marshall Space Flight Center in Huntsville Ala.
The component was manufactured using selective laser melting. This method built up layers of nickel-chromium alloy powder to make the complex, subscale injector with its 28 elements for channeling and mixing propellants. Okay, so I won’t be going to Best Buy to get a printer tomorrow after all….sigh.I don’t think they will have the 28 element laser melting model.
“This entire effort helped us learn what it takes to build larger 3-D parts — from design, to manufacturing, to testing,” said Greg Barnett, lead engineer for the project. “This technology can be applied to any of SLS’s engines, or to rocket components being built by private industry.”
One of the keys to reducing the cost of rocket parts is minimizing the number of components. This injector had only two parts, whereas a similar injector tested earlier had 115 parts. Fewer parts require less assembly effort, which means complex parts made with 3-D printing have the potential for significant cost savings.
“We took the design of an existing injector that we already tested and modified the design so the injector could be made with a 3-D printer,” explained Brad Bullard, the propulsion engineer responsible for the injector design. “We will be able to directly compare test data for both the traditionally assembled injector and the 3-D printed injector to see if there’s any difference in performance.”
Early data from the test, conducted at pressures up to 1,400 pounds per square inch in a vacuum and at almost 6,000 degrees Fahrenheit, indicate the injector worked flawlessly. In the days to come, engineers will perform computer scans and other inspections to scrutinize the component more closely.
One important thing about this technology is it will allow missions that are far from Earth to have an infinite number if spare parts available, they would just take a 3D printer with them and print replacement parts as they are needed. Wonder when the Warp drive will arrive???
This is the seminal technology of today, tomorrow, and the next century. Almost any conceivable part, no matter how complex the shape, can be created as a single piece, or at least far fewer parts than current technology can provide. I don’t know, but I believe that printing at the micron level is being done right now with the work done by a doctoral student on the East coast several years ago. The limitation on the accuracy of printing at micron levels was enforced by the chaotic motion of ink jets not far from their emission point. She figured out how to control that chaotic motion, opening up the promise of printing circuits and even silicon down to at least the 100 level, not good enough for super high speed processors, but good enough for volume printing of masses of slower processors.
A company called Tethers Unlimited, beyond its titular objective, is developing a thing called “spiderfab” (http://www.tethers.com/SpiderFab.html) where a 3D printer is used on orbit to create and assemble large structures on orbit without the boost of large, unwieldy objects. Things such as that should put a knife in the belly of the SLS. There is no reason for anything much bigger than the F9 Heavy. With a high efficiency second stage, it should be able to orbit up towards 70 mT. If that throws materials into orbit rather than whole objects, the whole economics of scale should shift by an order of magnitude. When orbital and beyond objects don’t have to be strong enough to withstand boost from Earth, and we don’t have to depend on the complex unfolding of antennae and solar panels, missions will have more reliability, and expensive hardware will not be lost to such stupidities. We can then afford to spend our boost mass on true mission hardware rather than the complexities and limitations of the support equipment. Large, wasteful fairings will be far less necessary.
What’s not to like…and we have not even considered what such printers will do to civilian economies.