NASA has successfully tested a 3D printed rocket engine nozzle made of aluminum for the first time, as part of a project aimed at reducing engine manufacturing costs and engine weight. Rocket engine nozzles need to withstand tremendous amounts of heat and pressure, so they must be manufactured using complex procedures and thousands of parts. With the new engine, the space agency aims to reduce the costs associated with deep space exploration and reduce the weight of the rocket so that it can carry more payloads.
In May 2023, NASA's RAMFIRE 3D printed rocket engine nozzle was tested in an environment with temperatures as high as 6,000 degrees Fahrenheit (about 3,300 degrees Celsius). Image: NASA
To create a 3D printed rocket engine nozzle, NASA had to develop an aluminum variant that was both suitable for additive manufacturing and capable of withstanding the stressful working conditions of a rocket engine. The engine nozzle is one of the most important components of a rocket, and like the combustion chamber, it must be able to withstand the extreme heat generated by the engine's combustion and combustion byproducts.
This engine nozzle is made from aluminum A6061-RAM2 and is part of NASA's Reactive Additive Manufacturing for the Fourth Industrial Revolution (RAMFIRE) project. This project is specifically dedicated to the development of 3D printed rocket engine nozzles, with a focus on introducing design changes to enable simplicity and cooling of the rocket.
A rocket engine nozzle is a bell-shaped component at the bottom that is typically cooled by supercold propellant flowing through the nozzle. This is accomplished by machining channels into the inner wall of the nozzle, which then flow back into the engine's combustion chamber to create thrust. These channels require hundreds or even thousands of individual components, which naturally complicates the manufacturing process and adds cost and weight.
NASA also created a 3D printed test tank out of the same material as the rocket engine nozzle. By using 3D printing technology to create the engine nozzle, NASA and its RAMFIRE project engineering and manufacturing partner RPM Innovation will be able to manufacture the rocket engine nozzle from a single piece. This significantly reduces costs and simplifies the engineering process while also making the nozzle lighter. All of these are huge benefits, especially since weight is one of the biggest limitations of rockets. Engineers must carefully balance the rocket's weight, propellant and payload to ensure it can actually lift off when launched.
The National Aeronautics and Space Administration (NASA) believes that advances in 3D printing technology in manufacturing rocket engine parts will allow it to carry more payloads, especially on interstellar missions. For RAMFIRE 3D printed rocket engine nozzles, NASA has successfully conducted 22 tests, with a cumulative test time of 579 seconds, or approximately 10 minutes, and test temperatures as high as 6,000 degrees Fahrenheit.
In addition, NASA and RPM Innovation built an aerosol nozzle and a cryogenic liquid tank. The aluminum for these parts was manufactured in collaboration with Elementum3D. Additive manufacturing for rocket manufacturing is a relatively new field, and Long Beach, California-based rocket company RelativitySpace has begun using 3D printing technology to manufacture fuel tanks, engines and other parts.