Director, Export Control and Nonproliferation Program, The James Martin Center for Nonproliferation Studies
3D Printing: Bringing Missile Production to a Neighborhood Near You
Following North Korea’s December 2012 test of its Unha-3 satellite launch vehicle, the South Korean navy recovered from the Yellow Sea a portion of the rocket jettisoned in flight.  ROK authorities and experts advising the UN Security Council’s sanctions committee subsequently analyzed the debris, to see what could be learned about North Korea’s rocket production know-how. The effort confirmed North Korea manufactured the rocket’s key components domestically, importing only common, off-the-shelf items. 
The North Korean government touts its indigenous manufacturing capability, highlighting in particular, the use of computer-driven machines to cut and shape metal into specific forms.  These devices – referred to as Computer Numerically Controlled or CNC machine tools – have been used for decades, and are valuable for missile and aerospace programs.
The frequency and variety of North Korea’s missile-related tests across 2016 – involving a solid-fueled rocket motor, submarine-launched ballistic missiles, and most recently, an Extended Range Scud missile – suggest an effort to accelerate development of these potential WMD delivery systems.
To speed up these advancements, North Korea may be tempted to experiment with new production methods such as 3D printing.
The recent emergence of 3D printing as an alternate manufacturing technology could change how states evaluate the cost of embarking on or (in the case of North Korea) accelerating missile development programs. 3D printing has the potential to greatly reduce the costs and expertise requirements of these and other proliferation programs. Employed strategically, 3D printing could reduce cycle times in development of missiles and other military systems – and with the right printers and software – even reduce the number of skilled engineers needed for such programs.
So what exactly is 3D printing and how does it compare with traditional manufacturing methods? 3D printing is also described as “additive manufacturing” whereas use of traditional CNC machine tools is considered “subtractive manufacturing.” Whereas CNCs cut and shape an object from a larger piece of material, additive manufacturing equipment builds a three-dimensional object layer-by-layer through the heating of metal powders or plastic resins into solid forms. The 3D object is, in effect, “printed.” Similar to their CNC-based subtractive manufacturing cousins, 3D printers are computer-controlled with the precise shape of the “printed” object determined by a design file used with the printer’s software.
Because 3D printers can produce a wide variety of three-dimensional metal or plastic objects, the potential commercial and industrial applications are vast, generating much buzz about the arrival of a new manufacturing revolution. Motivated by the potential cost and technical advantages, the U.S. National Aeronautics and Space Administration (NASA) and aerospace manufacturer Space-X are already experimenting with 3D printing in the manufacture of rocket engines.  The U.S. and British Navies have been using 3D printers on aircraft carriers at sea to produce customized drones during deployments.  The revolutionary implications for nonproliferation of this new manufacturing method warrant closer consideration.
Matthew Kroenig and Tristan Volpe assessed the nuclear nonproliferation dimension of this development with their article titled “3D Printing the Bomb?” and the topic is garnering attention among policy analysts.  Much of the concern surrounds whether 3D printing represents a new way for a state-level WMD program to circumvent nonproliferation export controls by offering a convenient way to produce sensitive (export controlled) components. As the Nuclear Suppliers Group and Missile Technology Control Regime developed their guidelines in an era when subtractive manufacturing was dominant, few export controls are in place specifically focused on 3D printers. However, traditional export controls can still apply to the inputs (design file and some metal powders) and outputs (printed object) of 3D printers.
The increased availability of home-use 3D printers complicates efforts to manage the proliferation risk posed by additive manufacturing. This development converges with the ongoing growth of e-commerce marketplaces and “one-click” shipping, meaning that individual online sellers are now able to manufacture their own goods as well as sell them. Of course, the capabilities of home-use 3D printers are far from the industrial-scale additive manufacturing equipment employed by the Lockheeds, Raytheons, and GEs of the world. However, the emergence of “makerspaces” –where 3D printers and other manufacturing equipment in a central workspace can be shared via a co-op type arrangement – may bring advanced production capabilities to a neighborhood near you. Even if a “makerspace” is not close by, a design file can be sent electronically to a 3D printing services company – or perhaps the customer’s own location if he/she has a suitable 3D printer on site. The production and sale of sensitive WMD-relevant dual-use goods by these new modes is not entirely hypothetical. Researchers at King’s College London and the Center for Nonproliferation Studies have identified export-controlled dual-use goods such as pressure transducers and freeze dryers for sale on e-commerce sites such as Alibaba.  As illustrated by University of California at San Diego students’ launching of a rocket with a fully 3D-printed engine, truly widespread “garage”-based production of rockets and other export controlled items may not be far away either. 
This emerging scenario will require creative thinking and solutions on the part of the nonproliferation community – and in a way that does not stifle the genuine benefits 3D printing offers for economic and human welfare. Traditional export controls will still be essential, but they will have to be supplemented by nonproliferation awareness-building beyond outreach to traditional industrial actors. Moreover, the transmissibility of 3D printing design files will demand similar attention in the cyber-security domain. Otherwise, states such as North Korea will be well-positioned to tap into the 3D printing revolution, learn from it, and incorporate it into their missile production capabilities. Well-resourced terrorist organizations and arms traffickers also may be tempted to exploit 3D printing for weapons production, and, just as legitimate commercial traders at the factory/warehouse level have been joined by new entrepreneurs at the garage/living room level, proliferators’ ranks may also be augmented by new illicit supply chains supporting them.
 “South Korea retrieves North Korean Unha-3 Rocket debris,” Spaceflight101.net, 15 December 2012.
 “Report of the Panel of Experts established pursuant to resolution 1874 (2009),” United Nations Security Council, Sanctions Committee (1718), Panel of Experts Report, S/2014/147 – pp. 22-24.
 Jeffrey Lewis and Amber Lee, “Happiness is a Warm CNC Machine Tool,” 38 North, 4 September 2013 (accessed on 1/22/2017)
 Kimberly Newton, “NASA Engineers Test Combustion Chamber to Advance 3-D Printed Rocket Engine Design,” NASA.gov, 8 December 2016.
 Kyle Mizokami, “The future of America’s aircraft carriers? Floating drone factories,” The Week, 21 April 2016; Jon Rosamond, “U.S., U.K. Navies Expanding Experiments Using 3D Printing,’ USNI News, 22 September 2015.
 See Matthew Kroenig and Tristan Volpe, “3D Printing the Bomb? The Nuclear Nonproliferation Challenge,” The Washington Quarterly, Vol. 38, No. 3, Fall 2015, pp. 7-19; for a rebuttal to Kroenig and Volpe’s piece, see Amy J. Nelson, “The Truth About 3-D Printing and Nuclear Proliferation,” War on the Rocks.com, 14 December 2015; for another influential work (particularly in the export control domain) on 3D printing and contemporaneous with Kroenig and Volpe’s piece, see Grant Christopher, “3D Printing: A Challenge to Nuclear Export Controls,” Strategic Trade Review, Vol. 1, No. 1, Autumn 2015, pp. 18-25.
 Charles Clover, “Alibaba: Weapons of mass ecommerce,” The Financial Times, 26 September 2014; Raymond A. Zilinskas and Philippe Mauger, “Biotechnology E-commerce: A Disruptive Challenge to Biological Arms Control,” CNS Occasional Paper No. 21, James Martin Center for Nonproliferation Studies, Middlebury Institute of International Studies at Monterey, nonproliferation.org.
 Kelsey D. Atherton, “University Students Launched a Rocket with Completely 3D-printed Engine,” Popular Science, 25 May 2016.
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