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Editor’s note: This is the first article in a two-part series exploring additive manufacturing.
The Pentagon has poured unprecedented funds into additive manufacturing as a potential game-changer for defense production. For example, in fiscal year 2024, the Department of Defense allocated roughly $800 million for additive, which was a 166% increase from the prior year. By FY2026, projects involving 3D printing will swell to an estimated $3.3 billion, based on the budget request. That may sound enormous, but it is still only a small fraction of a research, development, test, and evaluation budget north of $100 billion. The appeal makes sense as 3D printing promises to provide surges to supply chains by making parts on demand, reducing the reliance on foreign suppliers, and enabling rapid design iteration. However, the increasing amount of data, from case studies to industry analyses, suggests that while additive is a powerful tool, it is not the only answer. This article takes a hard look at where additive excels, where it falls short, and asks if there is another approach that is more pragmatic but essential for building the next generation of military hardware. The question is not whether we should invest in additive manufacturing, but whether we are investing in it in proportion to its realistic role.
My background is a blend of experience working for conventional primes and venture-backed startups. As a veteran of the aerospace and defense manufacturing industry, the company I work for has a vested interest in future factory platforms. However, this article is not meant to champion a particular company or solution. Rather, it reflects my opinion of the broader challenges and opportunities facing the United States when it comes to the challenge of the defense industrial complex.
The Allure of Additive Manufacturing
There’s no question that additive manufacturing has delivered some impressive wins in defense. Complex, high-performance components that were once impossible to make are now being 3D-printed and qualified for use. Across the military, each service branch has piloted additive to sustain aging equipment by printing legacy spare parts that suppliers no longer make. The U.S. Army, for instance, uses 3D printers at depots to fabricate obsolete vehicle parts on-demand, avoiding long lead times. The Navy’s “Print the Fleet” initiative has explored printing everything and envisions someday printing larger components like aircraft wings or small drones in the field.
In theory, additive manufacturing offers three big advantages for defense. It provides design freedom where engineers can create geometries previously impossible to build. In addition, agility and customization, where traditional manufacturing may require custom tooling or molds for each part. There are real business cases where additive manufacturing wins outright: low-volume, high-complexity, or high-tooling-cost parts. In a world of rapidly evolving threats, such agility is a huge plus.
These advantages are real, and they explain why the Department of Defense’s 2021 Additive Manufacturing Strategy and subsequent budgets have treated additive as a core capability to outpace adversaries. Defense contractors have integrated 3D printing into the production of satellites, aircraft, and munitions, and venture capital has flowed into startups aiming to 3D print as much as possible. Yet, public documentation of true serialized use is scarce. Many “success stories” turn out to be trials or one-off demos rather than sustained, high-rate production. Alongside the success stories, a more complicated reality is becoming clear. If you scratch beneath the hype, many in industry now acknowledge that additive is a fantastic tool for specific jobs and can be a costly mistake for others.
Hard Truths: Where Additive Manufacturing Falls Short
Despite the tremendous potential of 3D printing, its limitations in defense applications are increasingly evident. A candid way to put it comes from a long-time additive manufacturing expert who quipped: “If you can manufacture something any other way, you probably should.” In other words, additive must earn its keep by doing what other methods cannot, otherwise, it often loses on cost, speed, or reliability. Challenges additive poses include high cost per part, labor/hidden costs, and limited throughput and scalability. Industrial metal printers are slow, and machine time is costly, often accounting for over 50% of the per-piece cost. Exotic metal powder feedstock can cost orders of magnitude more than equivalent bar stock or sheet metal. According to a comprehensive NIST review, “in many instances, the cost of producing a product using additive manufacturing exceeds that of traditional methods.”
Metallic 3D-printed parts do not yet match the material properties of the best forged or wrought components in all cases. A naval materials expert noted that while a printed part can “meet or exceed the properties of a cast product”, it is “impractical [at this point] to meet properties equivalent to a wrought product” that’s been forged or treated. Military programs have been cautious, often limiting additive to non-critical components or running lengthy parallel testing for critical ones. There is significant research and development that is ongoing with a goal to improve additive materials and processes, but today, quality assurance is still a significant challenge in larger adoption.
The vision of pressing “print” and coming back later to a finished part is an oversimplistic version of reality. Highly skilled technicians and engineers are needed to fine-tune the print parameters, design proper support structures, and perform inspections and finishing. The Department of Defense has recognized some of these hurdles. Given these challenges, the initial euphoria around printing “anything and everything” for defense has tempered. However, additive is a relatively young technology, and its learning curve is steeper than that of casting or forgings, which are already highly optimized.
A few years ago, a well-known aerospace startup set out to build an entire rocket almost exclusively with 3D printing, from engines to fuel tanks to body. The theory was that printing the rocket would allow rapid iteration and lower part count. The company did prove that large, printed structures can fly: Its first rocket, roughly 85 percent additively manufactured by mass, reached space in 2023. However, this all-additive rocket experiment revealed serious growing pains. Cracks emerged in printed components, and large thin-walled sections like pressure vessel domes proved extremely difficult to print without defects. Ultimately, the engineers had to admit that their next rocket could no longer be “90 percent additively manufactured”. In the end, printing was reserved for where it made the most sense and was conventional — manufacturing took care of the rest. The attempt wasn’t a failure as it advanced the state of the art, but it proved that 3D printing alone couldn’t yet deliver a robust, cost-effective product at full scale.
Across the defense-aerospace industry, lessons learned are steering teams away from additive absolutism. A senior Boeing additive manufacturing leader summarized it well: Additive is great for complex parts that are hard to machine, like those with internal cooling or consolidated assemblies, but for “simple parts such as brackets or castings,” it will “be more expensive…and have negative trades” compared to traditional methods. In other words, use 3D printing where it genuinely adds value, and don’t use it where a block of metal and a good mill can do the job just fine.
John Borrego is the senior vice president of aerospace and defense at Machina Labs. He has extensive experience in aerospace and defense, spanning both heritage primes and high-growth startups. He has held technical and leadership roles at Northrop Grumman, SpaceX, Rocketdyne, and Los Alamos National Laboratory, where he focused on advanced manufacturing for aerospace and defense applications. His work bridges traditional defense industrial power with emerging agile technologies. Opinions expressed in this article are his own and do not reflect the views of any company or government agency.
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Image: Cpl. Grace Gerlach via DVIDS.
