Relativity Space Changes Course On Path To Orbit

March 17, 2025 by Tom Nardi 25 Comments

In 2015, Tim Ellis and Jordan Noone founded Relativity Space around an ambitious goal: to be the first company to put a 3D printed rocket into orbit. While additive manufacturing was already becoming an increasingly important tool in the aerospace industry, the duo believed it could be pushed further than anyone had yet realized.

Rather than assembling a rocket out of smaller printed parts, they imagined the entire rocket being produced on a huge printer. Once the methodology was perfected, they believed rockets could be printed faster and cheaper than they could be traditionally assembled. What’s more, in the far future, Relativity might even be able to produce rockets off-world in fully automated factories. It was a bold idea, to be sure. But then, landing rockets on a barge in the middle of the ocean once seemed pretty far fetched as well.

Of course, printing something the size of an orbital rocket requires an exceptionally large 3D printer, so Relativity Space had to built one. It wasn’t long before the company had gotten to the point where they had successfully tested their printed rocket engine, and were scaling up their processes to print the vehicle’s propellant tanks. In 2018 Bryce Salmi, then an avionics hardware engineer at Relatively Space, gave a talk at Hackaday Supercon detailing the rapid progress the company had made so far.

Just a few years later, in March of 2023, the Relativity’s first completed rocket sat fueled and ready to fly on the launch pad. The Terran 1 rocket wasn’t the entirely printed vehicle that Ellis and Noone had imagined, but with approximately 85% of the booster’s mass being made up of printed parts, it was as close as anyone had ever gotten before.

The launch of Terran 1 was a huge milestone for the company, and even though a problem in the second stage engine prevented the rocket from reaching orbit, the flight proved to critics that a 3D printed rocket could fly and that their manufacturing techniques were sound. Almost immediately, Relativity Space announced they would begin work on a larger and more powerful successor to the Terran 1 which would be more competitive to SpaceX’s Falcon 9.

Now, after an administrative shakeup that saw Tim Ellis replaced as CEO, the company has released a nearly 45 minute long video detailing their plans for the next Terran rocket — and explaining why they won’t be 3D printing it.

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A blue-gloved hand holds a glass plate with a small off-white rectangular prism approximately one quarter the area of a fingernail in cross-section.

AI Helps Researchers Discover New Structural Materials

February 27, 2025 by Navarre Bartz 18 Comments

Nanostructured metamaterials have shown a lot of promise in what they can do in the lab, but often have fatal stress concentration factors that limit their applications. Researchers have now found a strong, lightweight nanostructured carbon. [via BGR]

Using a multi-objective Bayesian optimization (MBO) algorithm trained on finite element analysis (FEA) datasets to identify the best candidate nanostructures, the researchers then brought the theoretical material to life with 2 photon polymerization (2PP) photolithography. The resulting “carbon nanolattices achieve the compressive strength of carbon steels (180–360 MPa) with the density of Styrofoam (125–215 kg m⁻³) which exceeds the specific strengths of equivalent low-density materials by over an order of magnitude.”

While you probably shouldn’t start getting investors for your space elevator startup just yet, lighter materials like this are promising for a lot of applications, most notably more conventional aviation where fuel (or energy) prices are a big constraint on operations. As with any lab results, more work is needed until we see this in the real world, but it is nice to know that superalloys and composites aren’t the end of the road for strong and lightweight materials.

We’ve seen AI help identify battery materials already and this seems to be one avenue where generative AI isn’t just about making embarrassing photos or making us less intelligent.

New Additive Manufacturing Contenders: HIP And Centrifugal Printing

July 20, 2024 by Maya Posch 6 Comments

Additive Manufacturing (AM) is a field of ever-growing importance, with many startups and existing companies seeking to either improve on existing AM technologies or market new approaches. At the RAPID + TCT 2024 tradeshow it seems that we got two more new AM approaches to keep an eye on to see how they develop. These are powder-based Hot Isostatic Pressing (HIP) by Grid Logic and centrifugal 3D printing by Fugo Precision.

Grid Logic demo at RAPID + TCT 2024. (Credit: Ian Wright)

Grid Logic’s HIP uses binder-less powders in sealed containers that are compressed and deposited into a HIP can according to the design being printed, followed by the HIP process. This is a common post-processing step outside of AM as well, but here HIP is used as the primary method in what seems like a budget version of typical powder sintering AM printers. Doubtlessly it won’t be ‘hobbyist cheap’, but it promises to allow for printing ceramic and metal parts with minimal wasted powder, which is a major concern with current powder-based sintering printers.

While Grid Logic’s approach is relatively conservative, Fugo’s Model A printer using centrifugal printing is definitely trying to distinguish itself. It uses 20 lasers which are claimed to achieve 30 µm accuracy in all directions with a speed of 1 mm/minute. It competes with SLA printers, which also means that it works with photopolymers, but rather than messing with FEP film and pesky Earth gravity, it uses a spinning drum to create its own gravitational parameters, along with a built-in parts cleaning and curing system. They claim that this method requires 50% fewer supports while printing much faster than competing commercial SLA printers.

Even if not immediately relevant to AM enthusiasts, it’s good to see new ideas being tried in the hope that they will make AM better for all of us.

A Look At 3D Printed Shoes: Hybrid, Fully Printed And Plain Weird

May 25, 2024 by Maya Posch 7 Comments

In the eternal quest to find more things to do with 3D printers, shoes have been in the spotlight for a while now. But how practical is additive manufacturing in this field really?

Adidas Ultra 4D running shoes with 3D printed midsole.

This is where [Joel Telling] of the 3D Printing Nerd YouTube channel puts in his two cents, with a look at a range of commercial and hobbyist ideas and products. Naturally, the first thing that likely comes to mind at the words ‘3D printed shoes’ is something akin to the plastic version of wooden clogs, or a more plastic-y version of the closed-cell resin of Crocs.

First on the list are the white & spiky Kaiju Gojira shoes from Fused Footwear, printed from TPE filament to order. TPE is softer to the touch and more flexible than TPU, but less durable. In contrast the Adidas Ultra 4D running shoes (from their 4D range) are a hybrid solution, with a standard rubber outsole, 3D printed midsole with complex structures and mostly fabric top part. Effectively a Nike Air in initial impression, perhaps.

Meanwhile ‘3D printed’ shoes ordered off Chinese store Shein turned out to be not 3D printed at all, while [Joel] seems to be really into fully 3D printed shoes from Zellerfeld, who appear to be using TPU. While it’s hard to argue about taste, the Adidas shoes might appeal to most people. Especially since they’d likely let your feet breathe much better, a fact appreciated not only by yourself, but also family members, roommates and significant others. So which of these (partially) 3D printed shoes would you pick, or do you have some other favorite?

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Electrospinning Artificial Heart Valves

March 29, 2024 by Dan Maloney 10 Comments

When you think about additive manufacturing, thoughts naturally turn to that hot-glue squirting CNC machine sitting on your bench and squeezing whatever plastic doodad you need. But 3D printing isn’t the only way to build polymer structures, as [Riley] shows us with this fascinating attempt to create electrospun heart valves.

Now, you may never have heard of electrospinning, but we’ll venture a guess that as soon as you see what it entails, you’ll have a “Why didn’t I think of that?” moment. As [Riley] explains, electrospinning uses an electric field to build structures from fine threads of liquid polymer solution — he uses polycaprolactone (PCL), a biodegradable polyester we’ve seen used in other medical applications, which he dissolves in acetone. He loads it into a syringe, attaches the positive terminal of a high-voltage power supply to the hypodermic needle, and the negative terminal to a sheet of aluminum foil. The charge turns the PCL droplets into fine threads that accumulate on the foil; once the solvent flashes off, what’s left is a gossamer layer of non-woven plastic fabric.

To explore the uses of this material, [Riley] chose to make an artificial heart valve. This required a 3D-printed framework with three prongs, painted with conductive paint. He tried a few variations on the design before settling on a two-piece armature affixed to a rotating shaft. The PCL accumulates on the form, creating a one-piece structure that can be gingerly slipped off thanks to a little silicon grease used as a release agent.

The results are pretty impressive. The structure bears a strong resemblance to an artificial tricuspid heart valve, with three delicate leaves suspended between the upright prongs. It’s just a proof of concept, of course, but it’s a great demonstration of the potential of electrospinning, as well as an eye-opening look at what else additive manufacturing has to offer.

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Learning 3D Printing Best Practices From A Pro

May 26, 2023 by Tom Nardi 13 Comments

It might seem like 3D printing is a thoroughly modern technology, but the fact is, it’s been used in the industry for decades. The only thing that’s really new is that the printers have become cheap and small enough for folks like us to buy one and plop it on our workbench. So why not take advantage of all that knowledge accumulated by those who’ve been working in the 3D printing field, more accurately referred to as additive manufacturing, since before MakerBot stopped making wooden printers?

That’s why we asked Eric Utley, an applications engineer with Protolabs, to stop by the Hack Chat this week. With over 15 years of experience in additive manufacturing, it’s fair to say he’s seen the technology go through some pretty big changes. Hes worked on everything from the classic stereolithography (SLA) to the newer Multi Jet Fusion (MJF) printers, with a recent focus on printing in metals such as Inconel and aluminum. Compared to the sort of 3D printers he’s worked with, we’re basically playing with hot, semi-melted, LEGOs — but that doesn’t mean some of the lessons he’s learned can’t be applied at the hobbyist level. Continue reading “Learning 3D Printing Best Practices From A Pro” →

The Shuttle Engine Needed 3D Printing, But…

April 23, 2023 by Al Williams 14 Comments

If we asked you to design a circuit to blink a flashing turn signal, you would probably reach for a cheap micro or a 555. But old cars used bimetallic strips in a thermomechanical design. Why? Because, initially, 555s and microcontrollers weren’t available. [Breaking Taps] has the story of NASA engineers who needed some special cooling chambers in a rocket design for the Space Shuttle. Today you’d 3D print them, but in the 70s, that wasn’t an option. So they used wax. You can see a video about the process, including a build of a model rocket engine, in the video below.

The issue is the creation of tiny cooling channels in the combustion chamber. You can use additional thin pipes brazed onto the engine. However, there are several disadvantages to doing this way, but early rocket engines did it anyway. Having the cooling path integrated into the system would be ideal, but without 3D printing, it seems difficult to do. But not impossible.

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