3D printing just feels like a Space Age technology.

I mean, you’re building up stuff from a bunch of layers of goo or powder, and sometimes even shooting those layers with lasers. And these days, scientists are out there 3D printing everything from batteries to food.

But maybe the most Space Age application is printing the very objects that get stuff into outer space. In early 2023, one company launched Terran 1… the first rocket that was mostly 3D printed. How successful was that launch?

Well, it depends on how you want to judge it. [intro music] Okay, let’s take one small step back. Why would engineers want to use any 3D printed parts inside their rockets? For a start, 3D printers can make very complex shapes way easier than your traditional rocket fabrication methods.

When you’re launching something into space, you want to keep things as light as possible without sacrificing strength. Engineers can often achieve that with a more complicated looking design. 3D printing also allows you to make fewer pieces that need to be welded together at the end. You can take something like a fuel injector, which could have, like, a thousand parts, and use 3D printing to print the whole thing in one giant, complex block.

That reduces both the amount of work spent sticking pieces together, and the number of potential weak points in the overall design. Plus, if you ask people in the business of 3D printing rocket parts, they’ll highlight how it takes a lot less time and money, too. Like instead of needing nine months to make that fuel injector, a 3D printer could do it in a couple of weeks.

And finally, if you need to ever change up the design of a certain part, 3D printing lets you do that way more efficiently, too. Usually, any re-worked parts would have to go back to the manufacturer to be re-designed, re-fit, and reproduced. But if you’re spitting pieces out of a printer, you can just adjust the code and hit “Print” again.

Over the past decade, aerospace companies have been incorporating 3D printed rocket parts. For example, back in 2014, SpaceX launched a Falcon 9 rocket that had a single 3D printed valve inside one of its Merlin engines. And just a few years later, RocketLab debuted its mostly 3D printed Rutherford engine.

But engineers want to keep pushing boundaries, and recently, they’ve been aiming high. The goal: an almost entirely 3D-printed rocket. Okay, right now it seems to only be one company.

Relativity. But they’ve claimed that they want their line of Terran rockets to be at least 95% 3D printed by mass… which may be a bit of a stretch goal. Their first attempt was the Terran 1, which began development in 2017.

And when it was finished, 85% of its mass was 3D printed. Not bad for a first try. It’s a two stage rocket, with two separate sets of engines.

And each engine in the first stage was built from just three printed pieces. Also, the printed metal exterior was thinner than a soda can would be if you scaled it up. It sounds pretty impressive, but how did they get there?

Well, to print a rocket, you need materials that are both printable and can withstand the forces and heat of space travel. Relativity’s engineers settled on two metal alloys… a proprietary aluminum alloy for the body, and a NASA-developed blend of copper, chromium, and niobium for those 3-piece engines. And they had at least two printing methods to choose from.

The first was a technique called laser powder bed fusion, which alternates between laying down a thin layer of powdered metal, and zapping it with a laser to fuse the whole thing together. With this method, you can make incredibly strong parts that are also incredibly detailed. The second kind of 3D printing is called directed energy deposition, or DED.

In a DED printer, the head has both a laser and a little nozzle that blows powdered material. As the head moves around the object, the laser melts tiny bits of the metal layer that was most recently printed, and the nozzle deposits some powder into that new melt. Direct energy deposition can make very large parts, but isn’t as great at detail.

So together, both techniques can help you print a 33-meter tall rocket. But could such a rocket survive a launch into outer space? Well, kind of.

Terran 1 had its maiden launch on March 22, 2023, and while it technically made it into space, it didn’t quite make it into orbit. The second stage engines failed to ignite, maybe because the valves opened too slowly, or because there was a bubble in the engine’s oxygen pump… or maybe even both. But Terran 1 did succeed in one crucial way.

About 80 seconds into the launch, it made it through what scientists call max q. It’s basically the moment when a rocket is under maximum stress as it plows through the atmosphere. In other words, by making it well beyond max q, Terran 1 showed that a mostly 3D printed rocket wouldn’t get torn to pieces.

Which is a very important proof of concept. But unfortunately for the Terran 1, that proof-of-concept flight was the end of its journey. Relativity quickly retired the rocket, and announced they’d be moving on to develop a larger and more powerful successor: the Terran R.

The company hopes to launch that 3D printed rocket in 2026. But they might end up changing how much of the rocket they want to actually be 3D printed… Terran 1 may never get another day in the headlines, but it’s helped pave the way for 3D printed rockets in the future. If not entire rockets, at least more rocket parts.

And it’s envelope-pushing like that that we here at SciShow want to celebrate. So to commemorate the Terran 1 launch, we’ve designed this special pin. Supplies are limited, so head on over to DFTBA.com/SciShow to pick up yours. [ outro ]