The night sky above Cape Canaveral Space Force Station in Florida was illuminated in March by the launch of Relativity Space’s Terran 1 rocket. This groundbreaking launch marked the debut of the first rocket constructed entirely from 3D-printed parts. Standing at an impressive 100 feet tall and 7.5 feet wide, Terran 1 showcased the immense potential of additive manufacturing in the aerospace industry. 3D printing, also known as additive manufacturing, is emerging as a pivotal technology, poised to enhance capabilities and drastically reduce costs in space exploration and beyond. The Terran 1 featured nine additively manufactured engines crafted from a revolutionary copper alloy, enduring scorching temperatures nearing 6,000 degrees Fahrenheit during its flight.
NASA materials engineers Dave Ellis and Chris Protz inspect the first 3D printed GRCop combustion chamber.
NASA materials engineers Dave Ellis and Chris Protz examining a 3D printed GRCop combustion chamber, highlighting NASA’s role in advancing additive manufacturing for aerospace components.
Developed at NASA’s Glenn Research Center in Cleveland under the agency’s Game Changing Development program, the Glenn Research Copper (GRCop) family of copper-based alloys is specifically engineered for the demanding conditions within high-performance rocket engine combustion chambers. GRCop, a sophisticated blend of copper, chromium, and niobium, is meticulously formulated to deliver exceptional strength, superior thermal conductivity, remarkable creep resistance – crucial for enduring stress at extreme temperatures – and robust low cycle fatigue properties, preventing material failure above 900 degrees Fahrenheit. These advanced alloys can withstand temperatures up to 40% higher than conventional copper alloys, leading to the creation of rocket components with enhanced performance and improved reusability.
NASA’s pursuit of these innovative materials dates back to the late 1980s, driven by the need for a spacecraft maneuvering engine capable of enduring numerous firings in low-Earth orbit. Rocket engines face intricate design and operational challenges, including repeated start-stop cycles that induce significant wear and tear on critical components.
Terran 1 rocket launch in March 2023, showcasing the fiery exhaust of a 3D printed rocket engine during its inaugural flight.
Terran 1 rocket’s exhaust plume during its March 2023 launch, illustrating the power of 3D printed rocket technology.
Dr. David Ellis, a NASA-supported graduate student during the Space Shuttle era, pioneered the GRCop alloy family. Throughout his distinguished career at NASA, Ellis continued to refine these alloys and broaden their applications.
“Combustion chamber liners in Space Shuttle Main Engines typically required replacement after just one to five missions,” Ellis explained. “Our research demonstrated that GRCop-84 could effortlessly achieve the target of 100 missions between maintenance and an engine life of 500 missions.”
Over years of dedicated alloy development, Dr. Ellis and his team collaborated with various NASA projects and programs, including the Rapid Analysis and Manufacturing Propulsion Technology (RAMPT) initiative, to advance different iterations of GRCop alloys. The latest iteration, GRCop-42, leverages diverse additive manufacturing techniques to produce single-piece and multi-material combustion chambers and thrust chamber assemblies for rocket engines. These advancements have not only elevated performance but also significantly reduced the weight and cost of critical thrust chamber components.
NASA’s research has revealed that GRCop alloys are exceptionally well-suited for integration with cutting-edge additive manufacturing methods. Modern techniques like laser powder bed fusion and directed energy deposition are at the forefront of creating GRCop components for a wide array of aerospace applications, as exemplified by the engines of the Terran 1 rocket.
In laser powder bed fusion, a 3D computer model is digitally sliced into ultra-thin layers. A specialized powder bed machine, acting akin to a precision printer, meticulously spreads and fuses these powder layers, one atop another, thousands of times to construct the complete part. This layer-by-layer bonding process yields material strength comparable to forged metal. The key advantage of this method lies in its ability to fabricate highly intricate parts, such as the sophisticated nozzles and cooling channels essential for combustion chambers and rocket nozzles.
The directed energy deposition (DED) process employs a laser to generate a melt pool on a surface. Powdered material is then precisely injected into this melt pool, solidifying upon cooling to build up the desired structure. Guided by a robotic arm, the laser and powder deposition system constructs the entire component layer by layer. DED excels in producing larger shapes and components compared to laser powder bed fusion, albeit with slightly less fine detail.
A 3D printed combustion chamber being manufactured using additive manufacturing techniques, showcasing the intricate process of creating rocket engine parts layer by layer.
A combustion chamber undergoing additive manufacturing, illustrating the layer-by-layer construction of complex components for 3D printed rockets.
“Development projects like RAMPT are crucial for accelerating the progress of new alloys and manufacturing processes for the benefit of commercial space, industry, and academic sectors,” stated Paul Gradl, principal engineer at NASA’s Marshall Space Flight Center in Huntsville, Alabama. “NASA undertakes the initial development risks, advancing technologies from early material concepts through rigorous certification. The integration of GRCop-42 alloys into commercial space applications, such as 3d Printed Rockets, perfectly exemplifies how NASA-led innovations propel industry capabilities and contribute significantly to America’s burgeoning space economy.”
Through a reimbursable Space Act Agreement, NASA provided invaluable technical expertise to Relativity Space, facilitating the transition of GRCop-42 from developmental stages to flight-ready application in the Terran 1 rocket. Relativity Space’s successful utilization of high-performance, additively manufactured rocket engine components, crafted with GRCop alloys, paves the way for their potential use in ambitious future missions to the Moon, Mars, and beyond, demonstrating the transformative impact of 3D printed rockets on the future of space exploration. Game Changing Development is a part of NASA’s Space Technology Mission Directorate, responsible for pioneering cross-cutting technologies and capabilities for NASA’s current and future missions.
