Some of the most complex rocket engine parts have been created and tested with the help of laser-based 3-D printing. A team from the NASA Marshall Space Flight Center designed two rocket injectors, which were created via 3-D printing with the help of Solid Concepts in Valencia, Calif. and Directed Manufacturing in Austin, Texas. The injectors each feature 40 individual spray elements, all printed as a single component rather than manufactured individually. Each injector was tested for 5 seconds, producing 20,000 pounds of thrust. The engineers created complex geometric flow patterns that allowed oxygen and hydrogen to swirl together before combusting at 1400 psi and temperatures up to 6000 °F. Traditional manufacturing methods for rocket engine injectors require the creation and assembly of 163 individual parts. But with 3-D printing technology, only two parts were required, saving time and money, and allowing engineers to build parts that enhance rocket engine performance and are less prone to failure, according to NASA. “We wanted to go a step beyond just testing an injector and demonstrate how 3-D printing could revolutionize rocket designs for increased system performance,” said Chris Singer, director of Marshall’s Engineering Directorate. “The parts performed exceptionally well during the tests.” Additive manufacturing not only helped engineers build and test the rocket injectors, it has also enabled faster and smarter testing, according to the engineers. Marshall has the capability to design and quickly produce smaller 3-D printed parts, allowing for any necessary modifications to the testing and rocket components. “Having an in-house additive manufacturing capability allows us to look at test data, modify parts or the test stand based on the data, implement changes quickly and get back to testing,” said Nicholas Case, a propulsion engineer at Marshall. “This speeds up the whole design, development and testing process, and allows us to try innovative designs with less risk and cost to projects.” The engineers continue to test increasingly complex injectors, rocket nozzles and other components with the goal of reducing manufacturing complexity, as well as the time and cost of building and assembling future engines. “We are working with industry to learn how to take advantage of additive manufacturing in every stage of space hardware construction from design to operations in space,” said Marshall propulsion engineer Jason Turpin. “We are applying everything we learn about making rocket engine components to the Space Launch System and other space hardware.” For more information, visit www.nasa.gov/sls.