In near future, Space tourism will become a reality, the first woman will reach the Moon, a permanent lunar base will be built, exploration of our solar system will boom, the first human mission will get to Mars, and commercial manufacturing in space will begin.
3D printing or additive manufacturing is an ongoing revolution in manufacturing with its potential to fabricate any complex object and is being utilized from aerospace components to human organs, textiles, metals, buildings, and even food. Additive manufacturing is defined by ASTM International as the process of joining materials together, layer by layer, based on three-dimensional model data.
Now 3D printing is being actively adopted by Aerospace companies. The launch systems (rockets), engines, and satellites we send into space are increasingly built using 3D printing and have given rise to the world’s largest and most sophisticated additive manufacturing facilities. This has enabled 3D printing in space and aerospace engineering, where the combination of affordability, versatility, speed, and precision make additive manufacturing a desirable choice.
Opportunities of 3D printing in Space
3D printing in space brings its own challenges and opportunities. One of the goals that NASA has set for itself in the near future is placing a human crew on the surface of Mars. Currently, that mission is scheduled to touch down on the Red Planet sometime in the middle of the 2030s. Additive manufacturing makes the construction of geometrically complex components possible, which would alternatively need highly specialized methods of production. Once requiring several distinct processing steps, components such as NASA’s rocket injectors can now be manufactured in one consistent AM process.
One of the biggest challenges to manned space missions is the expense. The NASA rule-of-thumb is that every unit mass of payload launched requires the support of an additional 99 units of mass, with “support” encompassing everything from fuel to oxygen to food and medicine for the astronauts, etc. Given the technical challenges and costs associated with leaving Earth and landing on planetary bodies (e.g., in the order of $300,000 per kg sent to Mars, according to Massa et al. 2007), sending all consumables needed to sustain crews is unrealistic in the long term.
In space ability to 3D-print parts would mean that on a longer mission as only raw materials need to be carried instead of carrying spares. This would to allow getting select hardware into space faster, more safely, and more affordably and making repairs and experimentation much easier. 3D printed objects can be recycled and made into entirely different objects. This would be incredibly useful on long trips when only limited materials are available onboard.
Space travel is unpredictable, sometimes a requirement of new kind of tool or object may emerge which was not anticipated earlier, 3D printer could allow the manufacturing of any such tool just by transferring design blueprints to the 3D printer. The object can then be manufactured onboard the ISS and be in the astronaut’s hands within a day. Utilizing 3D printers onboard these flights could allow space travelers to construct replacement equipment as needed, greatly reducing the cost and timescale of such a mission.
Technologies that work in an environment with gravity may not function in zero-g. On the other hand, the absence of gravity enables new solutions that may not work on our planet’s surface. The “zero-g” environment of space orbit opens doors to print materials not possible under the influence of earthly gravity, parts, and spares can be printed on-demand, and structures can be built that wouldn’t survive the stresses of launch.
NASA’s Orion spacecraft, launched in 2019 used more than 100 3-D-printed parts jointly engineered by Lockheed Martin, Stratasys, and Phoenix Analysis & Design Technologies. It was the first time that 3-D parts have been certified for deep space use. Deep space, or outer space, represents the physical universe beyond Earth’s atmosphere.
Economic advantages are a further offering of additive manufacturing in comparison to conventional subtractive manufacturing methods. Practically eliminating the requirement for re-tooling or revision of manufacturing procedures for new parts, components can effectively be produced on-demand using a single machine, meaning that economy of scale is achieved much more easily.
The critical benefit of utilizing additive manufacturing for space applications is that it can be employed to significantly decrease the mass of components. Additive manufacturing methods can be utilized to conveniently hollow out components with closed cells, pockets, and holes to drastically reduce the mass of components. In contrast, subtractive manufacturing almost always creates ‘solid’ components of uniform density. Weight reductions of an astounding 70% have been evidenced for satellite components created by AM. This is not a trivial matter as the reduction of the mass of satellite components significantly decreases the amount of fuel needed to launch the satellite and to maneuver it upon reaching orbit.
One of the great things about manufacturing in microgravity, though, is that we can actually make structures that wouldn’t be able to support their own mass if they were on Earth. That allows us to do really interesting things. For example, we can make a spiderweb-like structure that can hold and stabilize its own weight in space. But if you put it down on the ground, it would collapse under the weight of its own mass.
Even further afield, on the surfaces of the Moon and Mars, structures need to be built using locally sourced materials, and large-scale 3D printing is a key part of that solution, too. One of NASA’s goals is In-Situ Resource Utilization (ISRU) that aims to locate, harness, and utilize resources (both natural and discarded material) at the site of exploration to create products and services for subsequent use. Manufacturing of products using Zero-gravity 3D printers is absolutely critical for advancing space exploration to Mars or other planets.
The utility of space 3D printers can be enhanced when combined with synthetic biology. Researchers from the Universities Space Research Association (USRA), MIT Lincoln Laboratory, and NASA outline ways that synthetic biology and 3-D printing can support life during deep-space human missions. Astronauts can pack Earth’s unique renewable resource: cells. Cells of fungi and bacteria, for example, can be reprogrammed with synthetic DNA to produce specific materials, like bioplastics. These materials can then be fed into 3-D printers to manufacture things the astronauts may need during spaceflight — everything from hardware and medical devices to medicine and food.
The authors envision using synthetic biology to produce custom biological “ink” to 3-D print whatever may be needed over the course of a mission. Such a process would give scientists “the autonomy to design for the unknown,” says Jessica Snyder, a USRA researcher who leads the synthetic biology task for the NASA Academic Mission Services.
3D printers are also very essential for space security. According to US DOD, their space assets have come at risk, due to activities of adversaries that can degrade, deny or disrupt their ability to operate in space. US DOD is advancing many programs of space security like On-orbit robotic assembly of satellites, using additive manufacturing.
It is building Orbital facility staffed entirely by remotely-operated probes that could maintain, upgrade and resupply the satellites. It is devising new ways to design satellites via cellularization, faster tempo to get the “cells” and/or low mass material to orbit, and ways to manipulate and assemble satellites on orbit by using highly capable robotics. Microgravity 3D printing is critical technology for automated on-orbit construction of very large structures and multifunctional space system components.
Victoria Bosomworth, associate aerospace and defence analyst at GlobalData says, “The rise of 3D printing technology in the space sector comes at a time when states are embracing space as a fundamental domain, as is evident through countries strengthening their defensive capabilities and the recent creation of ‘space commands’ by states such as the US, UK, France and Germany. Recognition of space as a theatre of strategic importance has also been underlined through NATO’s decision to extend its Article 5 to include attacks in space. In addition to a rapidly escalating space race by commercial companies, to further the nascent but growing space tourism industry, the increasing importance of defence platforms in space paves the way for the rise of 3D printing as not only a beneficial but essential part of the space sector’s production process.”
Challenges of 3D printing in space
However, 3D printing in space is definitely not easy. In space, gravity is not that much less than it is on Earth. The gravity in space is 88% of Earth’s gravity. There is also no air in space. The biggest difference in space is that we don’t have the benefit of gravity to help us put things where we want to put them, so we have to rely on other forces to do the depositing of material.
Though the basic design of a 3D printer stays the same, printing in zero gravity requires special considerations. For one thing, without gravity to hold liquid layers together before they cool, the material itself must be sticky between layers. Due to the lack of gravity, 3D printers need to find a way to hold parts into place and keep layers together during the FDM process. There have been some recorded cases of 3D printed tools getting stuck onto build plates to the point that the part was damaged and even the printer.
Also, in a zero-gravity environment, we don’t have any natural convection like air currents that move naturally to help with cooling. So we have to build thermal control into the 3D printing system to keep the hot parts hot and the cool parts cool.
3D printing leaves you with imperfect surfaces. Looking under a microscope close up at a 3D printed part and this will become more evident. This might be ok here on Earth but space requires another level of precision as there is very little room for error. This surface poses a risk of developing cracks and being damaged by the countless flying objects found in space
Notwithstanding the process of making them, each of the components meant to fly in space needs to go through long, ruthless tests. Before any component can be inducted into any space mission, it has to go through layers of strenuous tests. These tests include testing of a component’s metallic strength, ability to work with other parts and above all, their space-readiness. The machinery will need to be protected from any outside factors like meteors, temperature changes, and any other environmental effects.
Space 3D printing technologies
“We used a filament deposition modeling process. There are several companies that make filament deposition modelling machines here on the ground—for example, Makerbot, 3D Systems, Cube Printer. The process works by taking a plastic filament which is extruded through a hot tip (basically it’s like a computer-controlled hot glue gun), which heats up the plastic almost to melting point to get it malleable,” said Principal investigator for the 3D printing in Zero-G Project, Quincy Bean.
“The reason why this process was chosen for use in space was because the filament is very easy to control in zero gravity. A lot of the other additive manufacturing processes use a powder or a liquid resin. Those would be very hard to control in microgravity. For instance, for the powder, you’d require a flat bed of powder. Without gravity that powder bed would just be a powder cloud, so you wouldn’t be able to make anything with that. The powder would also be extremely hard to handle in microgravity.”
The liquid resin would be similarly hard to handle because the additive process that uses the resin requires a vat of resin. Without gravity that vat would just be a big ball floating around.We haven’t seen anything go too terribly wrong with the process that we use. The biggest problems we’ve seen are the parts sticking too well to the build plate that the 3D part is built upon.
However, according to the CIGIT president Yuan Jiahu that developed Chinese 3D printer, there are still some issues to solve. For instance, it is still problematic to create complicated shapes when using multiple materials. Nevertheless, the 3D-printer already showed its potential and: “Once we make breakthroughs in these areas, we can start fully using this 3D-printer for high-end applications in space”.
NASA scientists are investigating, is 3D printing with regolith. Regolith is somewhat like sand — little bits of crushed rock created by millennia of asteroid impacts. However, since there is very little weathering compared to Earth, regolith is basically super-sharp dust. As you can imagine, that poses all sorts of challenges for researchers. The abrasive sand tends to get into machinery and clog up operations. Regolith doesn’t behave exactly like sand, and requires some trickery to get it into 3D printable form. However, scientists are hopeful for the future. “We’ve proven it’s a viable
“We are breaking new ground not only in the way we manufacture in space but also in the way we operate and approve space hardware that is built in space, rather than launched from Earth,” Werkheiser, a 3D printer manager at NASA.
Countries race to develop Space 3D printers
Within the space sector, a number of large aerospace companies have increased their investment in the 3D printing of spacecraft, satellites and rockets. In February 2021, Airbus announced they were using AM for the production of 500 radio frequency components for their Eurostar Neo spacecraft, which are set to join the Eutelsat fleet. The ArianeGroup, a joint venture between Airbus and Safran, has made great strides with their Ariane6 launcher – using 3D printing to reduce the number of parts required on the injector head from 248 to only a single component. They have also managed to 3D print a combustion chamber using AM technology, which has been successfully tested.
Boeing has been a prominent contender in the 3D printing field for some time, particularly in the territory of satellites, producing the first 3D printed antennae in 2019. Boeing also witnessed significant success using AM technology to print components of its SES-15 spacecraft. A slightly newer firm, Relatively Space, has also been challenging the market through the production of their first completely 3D printed rocket, known as ‘Terran 1’. Their latest version, ‘Terran R’, will be both entirely 3D printed and reusable. Lockheed Martin has also partnered with Relativity Space for an upcoming NASA mission in 2023, involving the construction of customised rockets.
NASA, the European Space Agency (ESA), and the space agencies of Russia, China, and India are all actively exploring, and already using, 3D printing to help meet their exploration, scientific, security, and commercial goals.
ZeroG Printer, which was built under a joint partnership between NASA and Made In Space was the first 3D printer designed to operate in zero gravity. It was launched into orbit on September 21, 2014, and served as a testbed for understanding the long-term effects of microgravity on 3D printing. Then, in 2015, the Additive Manufacturing Facility (AMF) became a permanent manufacturing machine on the ISS, capable of off world manufacturing in the hands of space developers.
Teams from Europe, China and Russia are all working on their own 3D printers to install on the ISS. Europe’s very first 3D printer in space is scheduled for installation aboard the ISS next year. “The POP3D Portable On-Board Printer is a small 3D printer that requires very limited power and crew involvement to operate,” explained Luca Enrietti of Altran, prime contractor for the compact printer.
Currently, the European Space Agency is experimenting with 3D printing satellites in a special thermoplastic called PEEK. Polyether ether ketone, abbreviated to “PEEK”, is the new and robust material that these CubeSats are printed in. What’s special is that rather than wiring up these CubeSats, electrically conductive lines can be 3D printed into the body itself.
These demonstrations are part of a bigger plan for the ESA. “The vision we have is to enable a new maintenance strategy,” says Ugo Lafont, “Space Station crews end up needing all kinds of items, all of which currently require transport from Earth. All of these could be 3D-printed instead – even toothbrushes – since PEEK is biocompatible.”
Chinese Academy of Sciences (CAS) recently ran several tests on a microgravity 3D printer that they had developed at the Research Center for Additive Manufacturing (3D Printing) Technology of Chongqing Institute of Green and Intelligent Technology (CIGIT).
Bioprinter company Allevi and Made in Space have teamed up to put the first bioprinter in space. Made in Space already has two 3D printers on the ISS, but with the addition of Allevi’s ZeroG extruder, they’re hoping to open up opportunities for research. The extruder would slot into the existing printer and print with biomaterials such as hydrogels or hyperelastic bone. The ZeroG extruder is designed with zero gravity in mind. Extrusion is carefully executed so each layer will stick to the last even without gravity to help. Special systems are also in place to regulate temperatures, since heat flows differently in space.
India’s space agency Indian Space Research Organisation, sent its maiden 3D-printed satellite part, a radio antenna, in the outer orbit in June 2017, and is now planning to leverage the next-gen manufacturing for adding more muscle against rivals in the global space war. “Components such as antennae, waveguides, brackets, thrusters, main oxidizer valves, combustion chamber liners, and propellant injectors, additively manufactured, are either in the prototyping stage or are actually flying,” says Ajay Parikh, business head of Wipro3D.
Russian astronauts aboard the International Space Station (ISS) launched Russia’s first 3D printed satellite, the Tomsk-TPU-120 into space. An important part of the 3D printed Tomsk-TPU-120 project is its use of experimental materials. The satellite is being used to test research models for the University’s Institute of Strength Physics and Materials Science, and scientists will be able to monitor the satellite’s internal temperatures (including that of its battery) and electronic component parameters as it orbits. This information will enable the scientists at Tomsk Polytechnic University to determine whether their chosen materials are suitable for future space missions.
A team from Russia plans to send a 3D printer to the ISS that can fabricate carbon fiber composites for rigid, durable microsatellites. The project will see two companies from the Skolkovo tech park, Sputnix and Anisoprint, team up with Moscow Polytechnic University to develop a 3D printer capable of blending traditional thermoplastics with continuous carbon fiber reinforcement to produce parts that can survive the depths of space.
China’s 3D Printer for space
The Chinese Academy of Space Technology (CASC) has conducted its first test of 3D printing in weightlessness. A cargo return capsule returned with two samples of continuous carbon-fiber-reinforced polymer composites successfully printed with the 3D printer, Chinese media reports. On 5 May 2020, a Long March -5B launch vehicle with a “space 3D printer” and a 3D-printed CubeSat deployer was launched into orbit with the aim of carrying out the first 3D printing tests in zero gravity for the Chinese Academy of Space Technology (CASC).
The Chinese Academy of Sciences designed the new printer, specifically created to operate in the microgravity environment of outer space. The device was created to quickly manufacture parts needed for spacecraft while the ship is in orbit. The printer has been developed by the Chongqing Institute of Green and Intelligent Technology (CIGIT) in collaboration with the Technology and Engineering Center for Space Utilization (CSU), which are both part of the Chinese Academy of Sciences (CAS).
China’s first in-orbit 3D printing test used continuous carbon-fibre reinforced polymer composites. According to CASC, it was the first time anyone had ever attempted this in space. Their final prototype was tested by making 93 parabolic flights in a reduced gravity aircraft near Bordeaux, France. The parabolic test flights, facilitated by the Space Administration of Germany, created microgravity environments that lasted for about 22 seconds at a time. The tests involved two printing technologies and five materials. Those materials included a fiber reinforced polymer, which has not been tested before by NASA. The objects printed are of a wide variety: wrenches, nuts, connecting rods and other practical tools. The test program was a complete success.
Duan Xuanming, who is the head of the 3D-printing research center at the Chongqing Institute, explained the details about this new breakthrough. The major benefits of this new printer are that it is bigger than the 3D-printer, which was sent earlier last month to the ISS. The printer can be tilted in every way without harming the printing quality. “You can print objects with a maximum size of 220mm x 140mm x 150mm, which is twice the size of NASA’s first zero-gravity 3D-printer. It is also larger than the upgraded version that NASA sent to the International Space Station on March 26”. This means that the parts are about 20 percent larger than the American printer can produce.
“It prints plastics and two kinds of composite materials, and we even completed tests in weightless and overweight environments, and of course in normal gravity situations. All three conditions create different 3D-printing parameters” he revealed. The printer is capable of production in a range of gravitational environments, accelerations, even while on a vibrating surface, researchers announced. If this new design is successful at producing affordable spacecraft equipment quickly, the invention could eliminate the need to carry much of the redundant equipment currently carried aboard spacecraft. Such an advance could significantly lower the cost of reaching space and carrying out missions.
The tests of the 3D printer will also validate the researchers’ automated control of the printing process. Previous microgravity 3D printing experiments on parabolic flights with airplanes required heating of the nozzle and troubleshooting. During this in-orbit test, the planned maneuvers ended without supervision.
3D printers for NASA’s Moon and Mars Exploration
Dr. Phil Reeves, vice president at Stratasys Strategic Consulting, said Tuesday that, thanks to the technology, the cost and complexity of space-ready components is tumbling. “Those 100 parts might replace 500 or 600 parts, as the printed technology can be used to create complex geometrical shapes,” he said. Reeves highlighted Orion’s docking station as an example where a previously complex part will now consist of just six individual 3-D-printed components locked together.
He also claimed that the 3-D parts supplied would offer a 50 percent weight-saving over previously used material, such as coated metal, without losing any strength. Another key element to the new materials is their ability to dissipate static. Reeves said the build-up of electric charge is a problem in space leading to a risk of “fried electronics or a dangerous spark inside a craft.”
The 3D Printing In Zero-G Technology Demonstration (3D Printing In Zero-G) experiment demonstrates that a 3D printer works normally in space. In general, a 3D printer extrudes streams of heated plastic, metal or other material, building layer on top of layer to create 3 dimensional objects. Testing a 3D printer using relatively low-temperature plastic feedstock on the International Space Station is the first step towards establishing an on-demand machine shop in space, a critical enabling component for deep-space crewed missions and in-space manufacturing.
Three-dimensional printing offers a fast and inexpensive way to manufacture parts on-site and on-demand, a huge benefit to long-term missions with restrictions on weight and room for cargo. After testing of hardware for 3D printing on parabolic flights from Earth resulted in parts similar to those made on the ground, the next step was testing aboard the space station. The test included printing items designed by students and results showed that 3D printers work normally in space. This work will contribute to establishing on-demand manufacturing on long space missions and improving 3D printing methods on the ground.
NASA and MADE IN SPACE are building a multi-armed 3d printing space robot named ARCHINAUT
NASA, along with US Company MadeInSpace (acquired by Redwire in June 2020) sent the first commercial 3D printer to the International Space Station (ISS) in 2016 – also known as the Additive Manufacturing Facility (AMF). Although metal 3D printing has become the norm in the aerospace and defence industry for some time, ceramic printing will be introduced to the ISS as the newest OOM facility through a Ceramic Manufacturing Model announced by MadeInSpace in 2020. While ceramics have initially proven more difficult to produce in zero-gravity spaces, evenly applied stress may in fact result in a stronger overall product. For the last few years, in line with increasing environmental concerns, NASA has also been exploring 3D printing recycling on-orbit through the introduction of the ReFabricator Unit and the polymer recycler in space in 2019.
Made in Space (MIS) company is attempting to make fiber optics in zero-gravity conditions via its MIS Fiber making machine. For this project, MIS has teamed up with Thorlabs, which has been working on the quality of heavy-metal glass fiber ZBLAN for more than a decade. Manufacturing ZBLAN fiber optics on Earth has been difficult due to gravity causing imperfections to its structure. Made in Space’s in-space manufacturing activities expand the commercial envelope to making valuable goods there, too,” said MIS CEO Andrew Rush. “We believe in-space manufacturing of goods valuable to people on Earth will soon drive significant commercial activity in space, perhaps one day creating a space-based economic boom.”
Right now, we have three materials on the space station. We have acrylonitrile butadiene styrene (ABS), which is kind of like Lego plastic and a common material used in 3D printers on Earth as well. Then, we have a high-density polyethylene (HDPE) that’s a more flexible and food-safe plastic. Polyethylene is also what milk jugs are made out of. Then, we also have a Polyetherimide/Polycarbonate (PEI/PC), which is an aerospace-grade polymer that produces stronger, more heat-resistant materials. It can actually hold strength in a vacuum and a low-temperature environment in space.
California’s space technology company partnering with Northrop Grumman and Oceaneering Space Systems on Archinaut, a 3D printer capable of working in the vacuum of space that will be equipped with a robotic arm. Archinaut is scheduled to be installed on an external space station pod and will be capable of in-orbit additive manufacturing, the fabrication and assembly of communications satellite reflectors or the repair on in-orbit structures and machinery. According to the contract with NASA, Archinaut’s orbital 3D printer will be developed by Made In Space while the manipulator arm is set to be made by Oceaneering Space Systems. Northrop Grumman was selected to provide systems engineering, control electronics, software, testing and the development of Archinaut’s ISS interface.
“Engineers would no longer be required to design structures or devices that need to be capable of withstanding the force of Earth’s gravity, fit inside of a rocket being launched into orbit, or surviving the massive vibrational and acoustic forces experienced during launch,” writes Scott J Grunewald in 3Dprint.com.
NASA / LaRC “SpiderFab” for automated on-orbit construction
Company called Tethers Unlimited (TUI) is currently developing architecture and a suite of technologies called “SpiderFab” for automated on-orbit construction of very large structures and multifunctional space system components, such as kilometer-scale antenna reflectors.
This process will enable space systems to be launched in a compact and durable ’embryonic’ state. Once on orbit, these systems will use techniques evolved from emerging additive manufacturing and automated assembly technologies to fabricate and integrate components such as antennas, shrouds, booms, concentrators, and optics.
Under a NASA/LaRC Phase I SBIR contract, TUI is currently implementing the first step in the SpiderFab architecture: a machine that uses 3D printing techniques and robotic assembly to fabricate long, high-performance truss structures. This “Trusselator” device will enable construction of large support structures for systems such as multi-hundred-kilowat solar arrays, large solar sails, and football-field sized antennas.
NanoRacks take First Steps towards On-Orbit Satellite Manufacturing, Assembly and Deployment
Made In Space, the space manufacturing company, and NanoRacks, the premier provider of commercial low-Earth orbit services, are partnering to provide a transformative new service for CubeSat developers: the Stash & Deploy satellite deployment service.
The Stash & Deploy service will leverage NanoRacks’ heritage in CubeSat deployment and Made In Space’s in-space additive manufacturing capabilities to deliver on-demand satellite manufacturing, assembly, and deployment to the space environment.
A variety of standard and customer-specific satellite components will be cached aboard a satellite deployment platform, such as the International Space Station. These components are “stashed” for rapid manufacture of CubeSats. Made In Space’s Additive Manufacturing Facility will be used to create custom structure, optimized for both the space environment and customer need.
As envisioned, customers will easily and quickly design their satellite or request a satellite be designed based on their requirements. Once designed, the optimized structure is created on orbit and the necessary components are integrated. The satellite will then be deployed into low Earth orbit. The entire assembly and deployment process will occur in a fraction of the time necessary to build, manifest, launch and deploy satellites from the ground.
DARPA award for 3D printing in space
If a 3D printer repaired a space mining machine and no human was there to press the button — well, could that even really happen? The Defense Advanced Research Projects Agency (DARPA) is investing up to $1 million over the next three years into research in Virginia Tech’s Department of Materials Science and Engineering that could make it possible.
The project will be led by Associate Professor Hang Yu, who will receive the funding beginning this year through DARPA’s prestigious Young Faculty Award program. The award guarantees $500,000 for two years, beginning this fall. If all benchmarks are met, the project could qualify for a third year and another $500,000.
Yu’s lab focuses on a metal manufacturing process called Additive Friction Stir Deposition (AFSD), which has drawn great attention recently from the aerospace and defense sectors. The low-temperature 3D-printing process can assemble components using metals, such as high-strength aluminum and titanium, without melting them. By building up layers of the materials, AFSD can manufacture components in a range of sizes and shapes that have better strength and fewer defects than components printed using other processes. AFSD also can be used to repair metal components.
Yu and his research team already work with the Department of Defense, including a Naval Air Systems Command project that examines ways to use low-temperature 3D metal printing to repair specialty aluminum components used in airplanes.
The DARPA project will focus on autonomous manufacture and repair for austere environments like space, creating new challenges for Yu’s lab. His team will work on it with a corporate partner, MetroLaser Inc., a California-based company that develops laser-powered optical diagnostics systems.
Kendall Knight, a doctoral student in Yu’s lab, will help direct the interdisciplinary research group working on the project. The group includes student members from materials science and electrical engineering and will use data analytics and artificial intelligence components.
“The way DARPA is looking at it is: ‘How can we print metal on the moon or Mars or in the deep ocean, and have confidence it will be strong enough?’” Knight said.
“The idea behind the project is that if you are printing metal outside of a nice factory, you are likely to get debris into your print — sand, dust, water, etc.,” Knight said. “Our first steps are doing some preliminary prints to understand how the defect spreads when we put it into the print.”
The scope of the work is significant. Team members also must figure out how they can remotely detect that debris and its effects on their prints. Furthermore, they want to predict the strength of their prints based on debris present in various remote environments.
“Everyone, so far, just talks about the physical science of it,” Yu said. “But this puts data science together with AFSD. This is actually an AI-related project.”
Data analytics and AI — artificial intelligence — will help the team relate the detection data signal, which is measured using MetroLaser’s laser acoustic resonance spectroscopy capabilities, to the strength of the printed materials.
There also are pressures to this work.
“Since the tests are relatively expensive, we need to draw trends to relate the debris level to the strength of the material in only a few tries,” Knight said.
For Yu, it’s a wide expansion of the foundational work he has done in AFSD. He recently published the first comprehensive textbook on AFSD with Elsevier and is considered a research pioneer of solid-state metal additive manufacturing.