Pearce says that it might take 10 to 14 months or more to conventionally manufacture a rocket engine’s combustion chamber. The number of components that make up a conventional rocket engine could be in the thousands. By contrast, a Relativity engine is printed in three primary components: the injector, the chamber, and the nozzle.
Pearce says 3D printing Terran 1’s chamber takes just two weeks “with another couple weeks to finish machining on it,” he says. “So instead of taking over a year, we have a new chamber in-house in over a month.”
The company’s 3D rocket printer is a bank of three large robotic arms. More robotic arms elsewhere on the line help to assemble components. As an example of the company’s automated assembly process, Pearce points to the Terran’s carbon composite tank, which is also printed and assembled in the factory.
“If we decide we need to change the [tank’s] diameter, it’s a configuration setting,” Pearce says. “We just reprogram the path to print that tank. We don’t have to change any of our tooling. That gives us much more flexibility.”
The robotic assembly process, Pearce says, streamlines the company’s vision of rapid assembly of rockets from minimal source materials—to the point that the whole process could perhaps could one day be ported to, say, an outpost on the Moon or Mars.
“One of the long-term visions is to be the company that goes to Mars, 3D prints a rocket and flies it back,” he says. “Even longer term, as we hopefully get to a place where humanity is interplanetary, are you going to want to fly everything you need on Mars from Earth? Or are you going to want to be able to manufacture on Mars?”
Once a rocket can be designed and built in California and/or Mississippi, Relativity has secured the launch pad to launch it from. Relativity announced earlier this year that it’s leasing launch facilities at Cape Canaveral Air Force Station in Florida, furthering the company’s drive toward its projected first test launch of Terran 1 in late 2020, according to Pearce.
A skeptic could, of course, counter that the proof is ultimately in the testing and launching. Can a 3D-printed and robotically manufactured rocket (with its payload, according to the company’s website, ranging between 700 kg and 1,250 kg) safely fly? And will it make economic sense for the company to send it up?
Relativity, which 16 months ago had just 14 employees, now has 85 employees plus another 200 projected jobs at their new Mississippi facility. Their team, Pearce says, is working to prove not just Terran 1 but also the concept behind how Terran 1 is made.
“We want to really establish that we’re the world’s first autonomous rocket factory,” Pearce says. “So we’re focusing on building out the Terran 1 rocket but also taking advantage of this 3D manufacturing process.”
He adds: “As an aerospace engineer, that opens up a lot of possibilities. It allows you to iterate more quickly. It allows you to focus on the design and engineering process and less on the manufacturing process.”