NASA is developing lighter and more efficient liquid rocket engine parts for future missions to the Moon, Mars, and beyond.
The Rapid and Analysis Manufacturing Propulsion Technology (RAMPT) project is advancing manufacturing methods that will improve the performance and reduce the production costs of rocket thrust chamber “assemblies.” These thrust chamber “assemblies” are made up of a combustion chamber, nozzle and joints. In rocket engines, fuel and an oxidizer are mixed and burned in the combustion chamber. This combustion produces hot exhaust, which is passed through a nozzle to accelerate the flow and produce thrust.
Thrust chamber assemblies are the most expensive parts of rocket engines to develop because they are highly complex and take a long time to manufacture. They are also the heaviest components within a rocket engine, and can significantly drive up the costs of NASA missions.
Novel Manufacturing Methods Will Cut Costs, Production Time for NASA Missions
To cut down on these costs, RAMPT replaces some traditionally metal pieces on the thrust chamber with composite material, uses advanced 3D printing methods to “print” the combustion chamber and nozzle, and employs innovative mechanical methods to fuse the two instead of using traditional metal joints.
RAMPT’s 3D-printed copper combustion chamber is covered with a composite wrap. This thin wrap – made of carbon fiber – provides structural support for the combustion chamber and replaces the traditional metal jacket, resulting in a weight savings of up to 50% compared to metal counterparts. The RAMPT nozzle is printed using directed energy deposition. This method uses a mechanical multi-axis arm to deposit material onto a surface. It then uses lasers to melt, deposit, and solidify the material into a structure. This manufacturing method can reduce the time required for rocket engine nozzle production from approximately two years to a few months compared to traditional processes. It also significantly reduces the part count since less pieces need to be manufactured individually.
Another manufacturing capability RAMPT is advancing to reduce the weight and cost of the thrust chamber assembly is “bimetallic joints,” to fuse the copper combustion chamber directly onto the nozzle without any additional metal joints or bolts. This direct fusion will reduce the overall weight of the thrust chamber assembly since it will enable engineers to forgo those heavy metallic bolts and joints in that section.
Advancement for NASA, Commercial Aerospace, and Related Industries
RAMPT’s advanced manufacturing method provides design options not previously possible and replaces the standard manufacturing process for assembling thrust chambers, which includes building the combustion chamber and nozzle individually and then bolting or welding the together.
Through this project, the RAMPT team will provide NASA and the commercial sector with entirely new advanced manufacturing capabilities that will result in shorter production times and reduced overall costs for aerospace and related industry projects. The RAMPT project is a partnership between NASA and Auburn University in Alabama. Auburn University tapped specialty manufacturing vendors for the production of the composite overwrap thrust chamber structural jackets, the directed energy deposition production of the nozzle, and the bimetallic joints.
The RAMPT team will continue with testing their thruster prototypes to help qualify the technology for use on future missions, from NASA’s Artemis lunar missions, to future deep space exploration of Mars and beyond.
The RAMPT team successfully hot-fire tested a 3D-printed copper alloy combustion chamber capable of 2,400 lbs of thrust in February 2019. This testing successfully demonstrated the hardware could withstand the associated heat and structural loads.
In 2020, the RAMPT team used directed energy deposition to create one of the largest rocket nozzles NASA has ever printed, measuring 40 inches in diameter
Technical Paper Resources:
Lightweight Thrust Chamber Assemblies using Multi-Alloy Additive Manufacturing and Composite Overwrap
Paul R. Gradl, Chris Protz, John Fikes, David Ellis, Laura Evans, Allison Clark, Sandi Miller and Tyler Hudson
In-Situ Alloying of GRCop-42 via Additive Manufacturing: Precipitate Analysis
David S. Scannapieco and John J. Lewandowski, Case Western Reserve University, Cleveland, Ohio, Richard B. Rogers and David L. Ellis, Glenn Research Center, Cleveland, Ohio.
|Principal Technologist||Project Manager|
|John Vickers (firstname.lastname@example.org)||John Fikes (email@example.com)|
Large-Scale 3D Printing for Rocket Engines