NASA’s First 3D Printed Rocket Engine Fires With 75 Percent 3D Parts

Summary: NASA's first 3D printed rocket engine, with 75 percent 3D parts, fires well Oct. 28 at Marshall Space Flight Center, says NASA's Dec. 17 news release.

During test firings on October 28, 2013, NASA's first-ever 3-D printed rocket engine parts successfully simulated workings of traditionally manufactured engines; tested at full power, 3D turbopump pumps 1,200 gallons of liquid hydrogen per minute, and the injector produced 20,0000 pounds of thrust: NASA/MSFC/David Olive, Public Domain, via NASA

Three years of making and testing individual 3D printed rocket engine parts at Marshall Space Flight Center in Huntsville, Alabama, are paying off as a 10-second group test on Oct. 28, 2015, yields 20,000 pounds of thrust, according to NASA’s press release on Dec. 17.

“We manufactured and then tested about 75 percent of the parts needed to build a 3D printed rocket engine,” says Elizabeth Robertson, project manager for Marshall Space Flight Center’s additively manufactured demonstrator engine. “By testing the turbopumps, injectors and valves together, we’ve shown that it would be possible to build a 3D printed engine for multiple purposes such as landers, in-space propulsion or rocket engine upper stages.”

For NASA’s seven successful tests, 3D printed rocket engine parts, such as injectors and turbopumps, are connected in a configuration that simulates their workings in a real engine. Known as a breadboard engine, the demonstrator rocket engine varies from the standard configuration that the final product will display on a test stand. A breadboard engine allows easy access to all parts and accommodates instrumentation, such as sensors, for obtaining critical data on functioning of individual parts.

“In engineering lingo, this is called a breadboard engine,” explains Nick Case, NASA liquid propulsion system engineer and testing lead for the 3D turbopump. “What matters is that the parts work the same way as they do in a conventional engine and perform under the extreme temperatures and pressures found inside a rocket engine. The turbopump got its ‘heartbeat’ racing at more than 90,000 revolutions per minute (rpm) and the end result is the flame you see coming out of the thrust chamber to produce over 20,000 pounds of thrust, and an engine like this could produce power for an upper stage of a rocket or a Mars lander.”

NASA’s seven test firings reveal that the 3D printed rocket engine seems capable of withstanding the temperature extremes that occur inside a flight rocket engine. The fuel that produces the rocket’s thrust burns at temperatures in excess of 6,000 degrees Fahrenheit (3,315 degrees Celsius). Prior to thrust, the turbopump delivers the fuel as liquid hydrocarbon that is cooled below 400 degrees Fahrenheit (minus 240 degrees Celsius).

Apart from bearings and seals, the majority of the parts in the test configuration are produced by additive manufacturing, known as 3D. Additive technology dramatically reduces production costs and time in comparison to traditional manufacturing methods by decreasing the total number of parts. Large parts requiring multiple components may be printed in one piece via 3D technology. For example, as compared with their traditionally manufactured equivalents, NASA’s 3D injector has over 200 fewer parts while a 3D turbopump emerges with 45 percent fewer parts. Manufacturing time for complex parts, such as valves, decreases from more than a year to only a few months.

NASA uses the selective laser melting (SLM) process for 3D manufacturing. A design entered into the 3D printer’s computer emerges from the printer in finished form as laser-fused layers of metal powder. Five suppliers collaborate with Marshall Space Flight Center’s engineers in converting designs for rocket engine parts to 3D reality.

“These NASA tests drive down the costs and risks associated with using additive manufacturing, which is a relatively new process for making aerospace quality parts,” says Elizabeth Robertson in assessment of NASA’s use of 3D technology. “Vendors who had never worked with NASA learned how to make parts robust enough for rocket engines. What we’ve learned through this project can now be shared with American companies and our partners.”

The 3D printed rocket engine that could! ~ NASA's breadboard engine, primarily composed of 3D printed parts, simulates workings of real engine but features spacious configuration to allow for easy access to parts: NASA/MSFC/Emmett Given, Public Domain, via NASA

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

3D breadboard engine: NASA/MSFC/Emmett Given, Public Domain, via NASA @ http://www.nasa.gov/centers/marshall/news/news/releases/2015/piece-by-piece-nasa-team-moves-closer-to-building-a-3-d-printed-rocket-engine.html

NASA 3D rocket engine test firing: NASA/MSFC/David Olive, Public Domain, via NASA @ http://www.nasa.gov/centers/marshall/news/news/releases/2015/piece-by-piece-nasa-team-moves-closer-to-building-a-3-d-printed-rocket-engine.html

For further information:

McMahan, Tracy. "Piece by Piece: NASA Team Moves Closer to Building a 3-D Printed Rocket Engine." NASA > Centers > Marshall > News > News Releases > 3-D Printing. Dec. 18, 2015.
Available @ http://www.nasa.gov/centers/marshall/news/news/releases/2015/piece-by-piece-nasa-team-moves-closer-to-building-a-3-d-printed-rocket-engine.html

NASA’s Marshall Center. "3-D Printed Tests: What Is A Breadboard Engine?" YouTube. Dec. 17, 2015.
Available @ https://www.youtube.com/watch?v=oGWPR0mcCLs

Roop, Lee. "NASA fires 3-D-printed rocket 'engine' on Alabama test stand." AL.com > News. Dec. 17, 2015.
Available @ http://www.al.com/news/huntsville/index.ssf/2015/12/nasa_fires_3-d_printed_rocket.html

Scott, Clare. "NASA's First-Ever Fully 3D Printed Rocket Engine is 75% Complete." 3D Print. Dec. 18, 2015.
Available @ http://3dprint.com/111799/nasa-3d-printed-rocket-engine/