NASA has recently unveiled a groundbreaking advancement in rocket engine technology with the creation of a 3D-printed rocket nozzle crafted from aluminum. This cutting-edge innovation is set to transform deep space exploration by significantly reducing the weight of rocket components, thereby increasing payload capacity for missions.
In a collaborative effort with Elementum 3D, located in Erie, Colorado, NASA's Marshall Space Flight Center in Huntsville, Alabama, has successfully developed a weldable aluminum variant capable of withstanding the intense heat generated by rocket engines. Historically, aluminum's low heat resistance and propensity to crack during welding have restricted its use in additive manufacturing for rocket parts. However, this new development, part of the Reactive Additive Manufacturing for the Fourth Industrial Revolution (RAMFIRE) project, represents a pivotal change.
Supported by NASA's Space Technology Mission Directorate, the RAMFIRE project is dedicated to producing lightweight, additively manufactured aluminum nozzles. These nozzles incorporate small internal channels designed to prevent overheating and melting. Unlike traditional nozzles, which often require the assembly of thousands of parts, the RAMFIRE nozzle is constructed as a single unit, streamlining production and significantly reducing manufacturing time.
Advancements in Additive Manufacturing
NASA and Elementum 3D have pioneered a new aluminum alloy, A6061-RAM2, specifically for this application. RPM Innovations in Rapid City, South Dakota, has employed this material in their laser powder-directed energy deposition (LP-DED) process to fabricate the RAMFIRE nozzles. This collaboration with industry partners not only enhances the supply chain but also makes additive manufacturing more accessible to NASA and the wider aerospace industry.
Paul Gradl, the principal investigator for RAMFIRE at NASA Marshall, emphasized the project's impact: "We've streamlined the manufacturing process, enabling us to produce large-scale engine components as a single build in just a few days."
Implications for Deep Space Missions
The lightweight characteristics of the new alloy are vital for NASA's Moon to Mars objectives, which necessitate transporting more cargo to distant space destinations. The alloy's capacity to endure high structural loads makes it ideal for manufacturing rocket components essential for these missions.
John Vickers, principal technologist for STMD advanced manufacturing, highlighted the significance of mass reduction: "Projects like this advance additive manufacturing alongside advanced materials, and will facilitate the development of new propulsion systems, in-space manufacturing, and infrastructure required for NASA's ambitious missions to the Moon, Mars, and beyond."
Successful Testing and Future Prospects
Earlier this year, the RAMFIRE nozzles underwent extensive hot-fire testing at Marshall's East Test Area. Utilizing liquid oxygen and liquid hydrogen, as well as liquid methane fuel configurations, the nozzles operated under pressures exceeding 825 psi, successfully completing 22 starts and 579 seconds of run time. This testing validated the nozzles' ability to perform in the harsh conditions of deep space.
Tessa Fedotowsky and Ben Williams, NASA engineers from the Marshall Space Flight Center, conducted a post-test inspection of the RAMFIRE nozzle. Gradl remarked, "This test series represents a significant milestone for the nozzle. After subjecting the nozzle to the rigors of a demanding hot-fire test series, we've demonstrated its capability to withstand the thermal, structural, and pressure loads for a lunar lander scale engine."
Beyond the nozzles, the RAMFIRE project has leveraged its aluminum material and additive manufacturing process to create other advanced components, such as a 36-inch diameter aerospike nozzle and a vacuum-jacketed tank for cryogenic fluids. NASA and its partners are actively sharing data and processes with commercial stakeholders and academia, exploring potential applications for satellites and other aerospace technologies.