AMCM ups the Game in 3D Printed Rockets with World’s Biggest Aerospike Engine

The leader in powder bed fusion printers, EOS and its sister company AMCM are stepping up their efforts to advance 3D printed space propulsion. Just last week, the company announced a partnership with Munich and Singapore-based software startup Hyperganic to accelerate innovation in space propulsion engineering. By integrating Hyperganic’s AI-powered algorithmic engineering software platform with EOS’ digital, high-end additive manufacturing solutions, the trio plans to revolutionize the field of space propulsion, which still uses very conservative designs.

As the first product in this collaboration, AMCM completed printing the world’s largest aerospike rocket engine on May 11, 2022, which was engineered using Hyperganic’s upcoming algorithmic engineering platform called Core. Set for release to a limited number of applicants on June 15, 2022, Hyperganic Core empowers designers to build 3D printing applications using advanced software algorithms without even a single piece of manual CAD.

The result is what Hyperganic CEO and Co-Founder Lin Kayser described as “the most complex AM part ever produced.” In fact, according to the long-time entrepreneur, the novel part broke all conventional workflows. The aerospike engine was automatically reengineered for production on an AMCM M 4K large scale, high productivity system for demanding AM applications, using EOS CopperAlloy CuCrZr. Standing at 80 cm tall, the engine demonstrates what’s possible when the power of software algorithms is combined with advanced AM systems.

Algorithmically engineered aerospike rocket engine printed in copper at AMCM. Image courtesy of AMCM/EOS/Hyperganic.

Both the private and public space sectors have turned to 3D printing technologies to advance rocket engine manufacturing throughout the last decade. From NASA to industry giants like Aerojet Rocketdyne and new startups like Launcher, many are traveling the AM road to develop and industrialize advanced 3D printed propulsion systems. So, why is this new engine so important to the space industry?

This technical innovation is supposed to make rocket engines more efficient than standard propulsion systems. For decades, the aerospike engine has been considered a promising solution. Even NASA tested the concept extensively on the ground and hoped to incorporate it into the Space Shuttle program, but due to budget constraints, the orbiter ended up being equipped with tried-and-tested bell-shaped nozzles instead. However, now that this technology can be built and engineered thanks to new advanced manufacturing techniques and AM’s design freedom, we are starting to hear more about aerospike rocket engines.

Unlike the standard bell-nozzle rocket engine, the aerospike engine nozzle looks like a spike and has significant advantages over traditional designs. Kayser points out that it is “altitude compensating” and “does away with the heavy nozzle extension, with a spike in the middle instead.” Additionally, it is easily up to 20% more efficient than bell nozzle engines, which is a dramatic improvement in the field of rocketry where even fractions of percentage points are worth pursuing, says Kayser.

“The challenge was always cooling the spike in the middle of the extremely hot exhaust gas. With Additive Manufacturing, we can finally produce these kinds of objects, and a few startups have been successful in initial designs. The problem now is to create a reliably working engine that can power a spaceship. This requires many iterations — and iterations in CAD are prohibitively complicated, especially for complex designs. This is where Hyperganic Core and Algorithmic Engineering come into play,” explained the CEO.

Kayser refers to initial designs of 3D printed aerospike engines done by Spanish startup Pangea Aerospace, done in collaboration with the German Aerospace Center (DLR) and industrial AM expert firm Aenium. Developed in 2021, Pangea aimed to test several aerospike engine designs that engineers believe can improve rocket engine efficiency by up to 15%. DLR carried out the first hot-run tests of this innovative engine, demonstrating the success of the new technology. Now EOS, AMCM, and Hyperganic hope to take aerospike engines one step forward.

Aerospike nozzle. Image courtesy of EOS/Hyperganic.

For the task, Hyperganic Strategic Engineering Lead Josefine Lissner created a completely algorithmic model for various aerospike designs. Within minutes, the team claims they can create almost any engine design imaginable, including injector heads, advanced heat transfer systems, and complex combustion chamber geometries with different thrust levels and sizes.

Selected from the many hundreds of designs, the first aerospike engine design was produced by Hyperganic in mere days. Then it was printed in one job on an EOS M 400-4 with zero supports, thanks to the newly launched EOS NickelAlloy IN718 process. After EOS had its first Inconel aerospike engine, it was automatically reengineered for production on the substantially larger AMCM M 4K system in copper. Dubbed by the companies as “the world’s largest 3D printed aerospike rocket engine,” this final copper engine was built from the ground up using Lissner’s Hyperganic Core algorithms.

The actual parts can be seen live at the upcoming RAPID + TCT event on May 17 through 19 in Detroit and at the Space Tech Expo USA in Long Beach, California, October 6 through 8.