by Clare Scott

In April 2023, NASA and The Ohio State University published a scientific paper about the development of a new alloy for additive manufacturing. Called GRX-810, the alloy is an oxide dispersion strengthened alloy, meaning that it is strengthened by tiny particles containing oxygen atoms and spread throughout it.

GRX-810 is an example of a superalloy. Current superalloys for AM can withstand temperatures of up to 1093°C (2000°F). In comparison, GRX-810 is twice as strong, over 1,000 times more durable, and twice as resistant to oxidation, says NASA. This means that it can withstand harsher conditions than other materials, making it an excellent option for parts inside aircraft and rocket engines.

The new superalloy is the latest in material developments that are making AM an increasingly attractive option for creating rocket engines. In March 2023, Relativity Space launched the first nearly entirely 3D-printed rocket, Terran 1. While the rocket did not reach orbit, it reached two goals: Max-Q, the point of greatest aerodynamic pressure on the rocket body, and main engine shut-off, or the completion of the main engine burn. Despite the failure to reach orbit, which is believed to be due to a secondary engine failure, the achievement of these goals demonstrates the viability of AM for the production of rocket engines.

Why has AM become such a popular technology for rocket engines? One reason is speed. AM allows multiple parts to be consolidated into just a few or even one part. Therefore, instead of the time it would take to produce hundreds of distinct, often complex parts, engineers only need the time it takes to additively manufacture one part. According to Relativity Space, the 10-story-tall rocket the team additively manufactured has 100 times fewer parts than a similar, conventionally produced rocket. The company also stated that it can build similar rockets using AM in a mere 60 days.

Reducing the number of parts reduces cost in addition to time. AM also enables the production of more complex parts, such as cooling channels, that would otherwise require expensive tooling. In addition, the ability to create lattice structures can greatly reduce the weight of the rocket engines.

Using AM for the production of rocket engines also opens up new material possibilities. Certain metals are extremely difficult to machine, but can be melted down and additively manufactured as easily as any other material. This means that metals with superior properties such as heat resistance, strength, etc. can be used to produce more advanced engines than before.

As space travel goals become more and more ambitious, with plans to return to the moon and travel to Mars among them, AM will have a large role to play. Space travel is expensive, but it can be much less so thanks to AM. Using the technology, engineers can more quickly develop and iterate on engine designs, speeding overall production. Speed, cost reduction, design flexibility, and material availability make AM an attractive option for sending us to space.