Today's innovations in science and technology are being driven by new capabilities in additive manufacturing. Also known as 3-D printing, this approach is changing the speed, cost and flexibility of designing and building future machines for space and earth applications.

NASA's Game Changing Development Program in the Space Technology and Mission Directorate has been actively funding research in 3-D printing and co-funded a recent groundbreaking test series with Aerojet Rocketdyne (AR) at NASA's Glenn Research Center.

Recently, AR in partnership with NASA, successfully completed the first hot-fire tests on an advanced rocket engine thrust chamber assembly using copper alloy materials.

This was the first time a series of rigorous tests confirmed that 3-D manufactured copper parts could withstand the heat and pressure required of combustion engines used in space launches.

In all, NASA and AR conducted 19 hot-fire tests on four injector and thrust chamber assembly configurations, exploring various mixture ratios and injector operability points and were deemed fully successful against the planned test program.

"The successful hot fire test of subscale engine components provides confidence in the additive manufacturing process and paves the way for full scale development," says Tyler Hickman, lead engineer for the test at Glenn.

The work is a major milestone in the development and certification of different materials used in this manufacturing process. According to AR, copper alloys offer unique challenges to the additive manufacturing processes. The microstructure and material properties can be well below typical copper.

So they have worked through a regimented process to optimize and lock down processing characteristics and have performed rigorous materials tests to know how the alloy performs structurally.

"Additively manufactured metal propulsion components are truly a paradigm shift for the aerospace industry," says Paul Senick, Glenn project manager. "NASA and its commercial partners continue to invest in additive manufacturing technologies, which will improve efficiency and bring down the cost of space launches and other earth applications."