These Engineers Want to 3D Print an Entire Rocket in 60 Days

February 13, 2020

Stargate is the world’s largest metal 3D printer
entirely built and designed in-house. The core of it includes three robot arms — one
of which is doing printing — and the other two are doing post post-processing. This is a six degree of freedom industrial
robot arm so it can move anywhere within about a 14 foot radius of its center. Right now the biggest parts we can make are
nine foot diameter and about 15 feet tall. And our printers are only getting bigger over
time. We aim to go from print to launchpad in less
than 60 days. We’re in an exciting time for spaceflight
innovation. There’s SpaceX’s reusable rockets, trips
to the farside of the moon, NASA’s commercial crew program is finally getting underway. And there’s a startup in LA’s aerospace
hub that’s on a mission to completely 3D print a rocket. We met up with one of their co-founders for
a look inside their operations. My name is Jordan Noone. I’m co-founder and chief technology officer
at Relativity. Me and Tim actually met when we were students. We’ve known each other for almost 10 years now. He graduated went to Blue Origin. I graduated went to Space X. Both Tim and I saw the promise of 3D printing
and we wanted to see the advantage of that applied to an entire rocket. But this isn’t the desktop 3D printing you’re
used to seeing us cover here at Seeker. This is a different type of additive manufacturing,
where an entire assembly line can be built around machines that use powerful lasers to
create industrial parts. There’s two main advantages that we see by
introducing the printing process to rocketry. The first one is reducing the part count on
the rockets. Traditionally rockets can have up to 100,000
thousand parts on them and we want to reduce that to about a thousand. The second area is in flexible manufacturing. When you have traditional manufacturing you end up with a factory full of very expensive tooling. By introducing 3D printing as a baseline to
the manufacturing process, you now have a flexible tool rather than a fixed tool. And that makes it much easier to change and
modify our designs, especially compared to any one else in the industry. While 3D printing has been explored by others
in aerospace for years now, Relativity tells us they’re doing something different. Often other companies will take a traditionally
manufactured assembly and look at each piece of it and try to figure out which one is best
applicable to printing and then print that traditionally designed part. For Relativity, it all starts from the ground
up. Stargate starts when a part is still on a computer and so in a digital environment
called CAD or computer aided design. Most of the rocket is basically just a system
to carry a fuel and dispense fuel. And so for that, to make sure you have like
the lightest system possible, you wanna make sure that wherever you move your fluids inside
your rocket which are liquid oxygen or your fuel. You want to do so super efficiently. Fluid flow can be harder to predict. So that’s when we use tools like a CFD which
is computational fluid dynamics and that’s basically asking the computer to kind of predict
the way that a flow of a certain fluid will move through a manifold and distribute itself
evenly. By doing that in a computer we’re able to
iterate really quickly so we can say hey how does my flow behave if I have a one inch hole
and it’ll tell you and then you move that by like maybe half an inch and you try different
things. And from that geometry you’re able to basically
tell the printer what it is you wanted to make. Just being able to maybe print three different
designs using the exact same tooling the exact same printer allows you to just kind of bake
that into the process, that kinda trial and error. And to make these future parts, Relativity
leans in on some key printing techniques. Stargate uses a direct energy deposition method
where you’re actually feeding a wire into a melting pool and moving that process around. Stargate prints the majority of the structural
components on the rocket. And that includes not only the propellant
tanks but the structural attachments, the payload encapsulation fairing and all of the pieces
that aren’t the engines on the rocket. One of the things that makes our tanks special
is our ability to 3D print them and we’re able to 3D print them in one piece which gives us kind of like good confidence in our
ability to be completely leak proof. When we talk about tank we actually mean like
a tank that can hold both liquid oxygen and liquid methane and so that’s usually generally
something you either put two tanks with or have some kind of complex divider you insert to separate the two propellants. That is one of the great advantages for us in that we’re able to print both of those tanks as one part. On the smaller scale that we use for the engines
and other smaller components, we use a methodology called DMLS or direct metal laser sintering
and that has become pretty commonplace across the industries. And that is done within a bed of powder. That bed powder is laid flat and then a laser
locally melts material where you want to build up your finished part. This process repeats itself, powder and laser,
until the part is finished, which could be as many as 10,000 layers. Here is a version of one of our printed domes. These domes represent the end caps that will
be on the ends of the propellant tanks on our rocket. There’s a variety of other equipment out on
the shop floor here including Stargate in the back, we have CNC Mills, heat treat furnaces and
a variety of equipment that supports the manufacturing not only for the rocket but for making the
3D printers as well. And another key element of Relativity’s
production model is automation. We have a patent that covers the real time
controls during the printing process and that patent covers novel techniques for applying
machine learning and A.I. The control station is here on my left then. But it’s mostly for monitoring now. So you can manually move the arms but traditionally
these are moved in an entire automated manner where you’re feeding the part designed essentially
to it piece by piece so it knows which parts of it to add at once. Once you know how you want the robot to move
during the printing process you have to be ready to do all of the dynamic controls and
feedback. We collect enough data both on what we’re
putting into the printers and what’s coming out of them in order to correlate that and
come up with control loops that can maintain the very high quality prints in a way that
we could not predict just on our own. This killer combo of automation, machine learning,
and 3D printing promises to deliver a new path for spaceflight. Our printing
technology has surpassed even where sci-fi has put some parts of technology which is often surprising to see. Aeon one is a fully 3D printed rocket engine
fueled by liquid oxygen and liquid methane. It is entirely printed in only three parts
and that is a testament to the part reduction that is achievable through the printing process. A similar engine with a similar internal configuration
could take up to three thousand parts when traditionally manufactured and we can make
them not only in three parts, but print those parts in only nine days. There’s still plenty of work ahead before
these engines are ready for their first official launch, but NASA is paying close attention. They’ve recently inked a 20 year partnership
with the Stennis Space Center for future testing. We’ve had over 100 hot fires of that under
a variety of revisions constantly modifying and improving the performance of it as we’ve
gone through that test campaign. The rocket that we’re selling is seven foot
diameter and one hundred and five feet tall. It weighs about one hundred and twenty thousand
pounds at take off and by weight it’s ninety five percent printed. This rocket is catching contracts with satellite
companies, even before it’s ever had its first test. They’re working towards a 2020 orbital test,
with 2021 as their official launch for commercial flights. We see a future where not only do we have
3D printing but we also have an automated production line handling everything that comes out of the printers. 3D printing is the special sauce of Relativity
but I think that comes into play in more ways than people realize. You have the ability to basically change your
designs and explore the design space at a much faster rate. You need kind of a lot of creativity to, and
a bit of audacity to kinda look at these problems that have been solved and try to
approach them in a different way. And so every day you get to sit down and say “oh you know have we tried this? Have we looked at that? You really have kinda blank slate to work with, so it’s a lot of fun. For more science documentaries, check out this one right here. Don’t forget to subscribe and keep coming back to Seeker for more videos.

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