NASA tests 3D printed rocket nozzle for deep space missions

To create the nozzle, NASA collaborated with Elementum 3D, a company based in Erie, Colorado, to invent a new type of aluminum alloy called A6061-RAM2 that is weldable and heat resistant enough for use on rocket engines. Another partner, RPM Innovations (RPMI) in Rapid City, South Dakota, used the new alloy and a special powder to build the nozzles using laser powder-directed energy deposition (LP-DED) technology.

The RAMFIRE principal investigator at NASA's Marshall Space Flight Center in Huntsville, Alabama, Paul Gradl, said that industry partnerships with specialty manufacturing vendors helped them advance the supply base and make additive manufacturing more accessible for NASA missions and the wider commercial and aerospace industry.

The new alloy could play a key role in NASA's Moon to Mars objectives that require the ability to send more cargo to deep space destinations. The lightweight rocket components made of the alloy could handle high structural loads and reduce the spacecraft's mass.

The principal technologist for STMD advanced manufacturing, John Vickers, said that mass was critical for NASA's future deep space missions. He added that projects like this matured additive manufacturing along with advanced materials. He helped evolve new propulsion systems, in-space manufacturing, and infrastructure for NASA's ambitious missions to the Moon, Mars, and beyond.

The nozzle was tested earlier this summer at Marshall's East Test Area using liquid oxygen, liquid hydrogen, and liquid oxygen and liquid methane fuel configurations. The nozzle performed well under pressure chambers exceeding 825 pounds per square inch (psi), which was more than expected. The nozzle completed 22 starts and 579 seconds, or nearly 10 minutes, of run time. This showed that the nozzle could operate in the most demanding deep-space environments.

RAMFIRE aluminum

Gradl said that this test series marked a significant milestone for the nozzle. He added that after putting the nozzle through the paces of a demanding hot-fire test series, they demonstrated that it could survive the thermal, structural, and pressure loads for a lunar lander scale engine.

The RAMFIRE project has also used the RAMFIRE aluminum material and additive manufacturing process to construct other advanced significant components for demonstration purposes. These include a 36-inch diameter aerospike nozzle with complex integral coolant channels and a vacuum-jacketed tank for cryogenic fluid applications.

NASA and industry partners are working to share the data and process with commercial stakeholders and academia. Various aerospace companies are evaluating the novel alloy and the LP-DED additive manufacturing process and looking for ways it can be used to make components for satellites and other applications.