Defectors from SpaceX and Blue Origin are developing a remarkable technology called 'Stargate' to help colonize other planets

Ellis helped bring 3D-printing to Blue Origin to quickly and cheaply build custom parts for the company. "That inspired me to see 3D-printing is the future of rockets," he said. "We saw the time savings in this totally new process to build rockets."

The kind of 3D-printing Ellis is referring to is called laser sintering. The system uses laser beams to bond powdered metal, layer by layer, into precise and complex structures that have minimal parts.

Ellis said that, so far, spaceflight companies are only dipping their toes into the technology. "They're only printing parts here and there and cannibalizing launch systems from the bottom-up," he said. "The problem with that approach is that there are close to 100,000 parts in a rocket."

That's why Relativity Space thinks it has a strong value proposition. "Other companies, by our estimates, are 3D-printing less than 1% of their parts, and we're looking at achieving 95% by the end of 2020," Ellis said, referring the company's planned "Terran" rocket.

Instead of roughly 100,000 parts, Terran might use just 1,000. The system is designed to launch up to a car-size satellite into low-Earth orbit.

Ellis said he got his start with internships at Blue Origin and eventually earned a full-time job there. He co-founded Relativity Space with another engineer named Jordan Noone and now serves as CEO.

Sources: Business Insider, LinkedIn

Noone, the company's CTO, is a former SpaceX employee who worked on Musk's Dragon spaceships and engines. Noone also interned at Blue Origin for a few months in 2013, while Ellis was at the company.

Sources: Business Insider, LinkedIn (1, 2)

Relativity Space is headquartered in western Los Angeles and has raised about $45 million since its founding in 2015, according to Ellis.

The startup also has a partnership with NASA's Stennis Space Center in Mississippi to test rocket engines. In total, Relativity Space has about 40,000 square feet of manufacturing and office space, employs 35 full-time staff, and has 14 advisors and consultants.

Sources: LinkedIn, Twitter

One newly acquired advisor is Tim Buzza, who was SpaceX's fifth employee. (He worked for Musk for nearly 12 years.) Buzza is an aerospace engineer and most recently served as the vice president of the launch program at Virgin Orbit, Richard Branson's rocket startup.

Source: LinkedIn

The company's 3D-printing approach could vastly reduce complexity and increase reliability, Ellis said, in addition to speeding up rocket development and manufacturing. "Rockets built and flown in days instead of years," boasts a slogan on Relativity Space's website. One of the company's major test cases is its first rocket engine, called Aeon.

Each Aeon engine starts out as high-temperature nickel alloy in powdered form.

Over the course of days, lasers sinter the powder into shapes that'd otherwise be difficult if not impossible to create using molds. The consistency and strength of the finished product is also easier to control.

Out of these industrial printers comes a single part. Building a similar structure with more traditional methods might require hundreds of parts welded together, along with countless bolts, nuts, and other fasteners, and months of effort.

"No one has really innovated on the fundamental manufacturing problems that the aerospace has dealt with over the past 50 years," Ellis said.

"They've all had a huge amount of hands-on labor and very complex supply chains. 3D printing ... removes complex tooling, it's very fast, and it reduces the labor required to make each product," he added.

Ellis said Aeon demonstrates that an experimental rocket engine can be made in days instead of months. "Since it's so much faster and cheaper, you can take more risk and try new ideas," he said. "You can see the product and future happen faster."

"We want to go from raw materials to flying a rocket in 60 days," Ellis said. "Normally a lead time for producing a rocket is 12-18 months. So this is significantly faster than traditional methods for the production time. And of course 60 days later, we can produce a totally different rocket style."

Aeon simplifies what would have been 2,700 individual parts from countless manufacturers into a few core pieces, Ellis said. "Because things are 3D-printed, they're more organic looking," he added. "They almost look like parts made by nature."

So far, it appears to be working. The first version of Aeon was designed, built, and test-fired within six months of Relativity Space's founding. That's extremely fast in the rocketry universe.

Versions of the Aeon engine have since been test-fired about 100 times at NASA's Stennis Space Center, and 10 will eventually go into each Terran rocket.

Relativity Space is building another rocket-engine test stand in Mississippi to speed up its development program for Terran.

Ellis said the Terran rocket should be reusable and inexpensive to make. The goal is to start with smaller payloads and be price-competitive with SpaceX's Falcon 9 rocket.

However, Relativity Space sees itself eventually printing larger and even more economical rockets.

Relativity Space's success or failure will ride on its Stargate system: the largest metal 3D printer on Earth, according to Ellis. It's designed to be the core technology that enables printing big rocket parts.

One Stargate system has already been built, but it's still being developed and tested.

Ellis said Stargate's cameras, sensors, and advanced software "make the printer more intelligent" than other 3D printers. For example, Stargate can study its own work, detect flaws, and even teach itself how to print complex parts faster.

Ultimately, Ellis wants a Stargate-like system fly on a Mars-bound mission — perhaps in the cargo hold of SpaceX's upcoming Big Falcon Rocket (or BFR). Such a spacecraft should be big enough to carry a versatile 3D-printing factory.

Source: Business Insider

A 3D printer on Mars could help colonists build necessary things like habitats. Instead of transporting these large, cumbersome structures to the planet, a factory made by Relativity Space might use Martian dirt to quickly build robust off-world homes.

"What do you need to make on another planet? We think there needs to be another company focused on this piece of the puzzle," Ellis said. "I would love to launch our factory to Mars, and then figure out how to scale and sustain that society very quickly."

Marco Cáceres, a senior space analyst at the Teal Group (an aerospace market analysis firm), said 3D printing on Mars isn't an outlandish idea. "If you're going to live on other planets, you'll need to produce hardware," he told Business Insider. "If something goes wrong, you need to have spare parts."

But for such a scheme to work, a 3D-printing factory would have to be able to use raw Martian materials as inputs. "If 3D-printing on other planets really, really works, and it's able to print large parts, that's a game-changing thing," Cáceres said.