Insider Brief
- DARPA is shifting the final phase of its NOM4D program from lab tests to small-scale orbital demonstrations to evaluate in-space construction techniques.
- Caltech and the University of Illinois Urbana-Champaign will conduct autonomous experiments in space in 2026, testing robotic assembly and polymerization methods.
- The research aims to enable future large-scale space structures, including antennas, solar arrays, and refueling stations, supporting national security and commercial applications.
Artist’s concept depicts structural assembly and novel composite-forming process experiments to be conducted in space in 2026 during Phase 3 of DARPA’s NOM4D program. (University of Illinois Urbana-Champaign)
DARPA is taking its experiment on building large space structures out of the lab and into orbit, aiming to demonstrate that novel materials and manufacturing techniques can enable the construction of structures far larger than a rocket can carry.
The Defense Advanced Research Projects Agency (DARPA) announced in an article it will transition the final phase of its Novel Orbital Moon Manufacturing, Materials, and Mass-efficient Design (NOM4D) program from further laboratory testing to small-scale orbital demonstrations. The pivot follows technical progress by research teams at Caltech and the University of Illinois Urbana-Champaign (UIUC), which have now partnered with commercial space companies to launch their technologies into space in 2026.
DARPA launched NOM4D in 2022 to address a fundamental constraint in space construction: the size and weight limits imposed by a rocket’s cargo bay. Traditional methods require structures to be compacted or folded for launch and then deployed in space. NOM4D proposes an alternative: stowing lightweight, flexible raw materials in rockets and constructing large structures in orbit, where gravity is negligible and does not distort the final shape.
“Caltech [California Institute of Technology] and the University of Illinois Urbana-Champaign have demonstrated tremendous advances in the first two phases and have now partnered in Phase 3 with space-launch companies to conduct in-space testing of their novel assembly processes and materials,” said Andrew Detor, DARPA NOM4D program manager. “Originally, Phase 3 was going to be about making things more precisely in the lab than we did in Phase 2. But we said, ‘You know, the maturity is there, and there would be more impact if we took the capabilities we have now and actually go demonstrate them in space to show that it can be done.’ Pushing the performers to do a demo in space means they can’t just sweep challenges under the rug like they could in a lab. You better figure out how it’s going to survive in the space environment.”
Testing New Assembly Methods in Orbit
Caltech’s experiment focuses on proving the feasibility of lightweight, modular construction in space. The team has partnered with Momentus Inc. to test its approach aboard the Momentus Vigoride Orbital Services Vehicle, which will launch on a SpaceX Falcon 9 mission in February 2026.
Their demonstration will be fully autonomous, with no human involvement after deployment. A robotic gantry system will assemble a structure made of composite fiber tubes—similar to an advanced version of a Tinkertoy construction set. The goal is to verify that these materials and assembly methods can create stable, large-scale structures in microgravity.
“The Caltech demo won’t be building a radio frequency (RF) antenna with the required electronics; rather it will show us if their assembly tech works in space and if they can build a structure using thin composite tubes with surrogate RF mesh material hanging on the inside of the perimeter truss,” Detor said. “If the assembly technology is successful, this would be the first step toward scaling up to eventually building very large space-based structures in the future.”
Meanwhile, UIUC’s experiment will focus on testing a new method for forming rigid composite materials in space. The team has developed a technique that turns a flexible sleeve of carbon fiber into a hardened structure through a process called frontal polymerization. Unlike traditional carbon-fiber manufacturing, which requires large autoclaves for heating and curing, this method starts a chemical reaction at one end of the material that then propagates through the structure, hardening it in place.
“The University of Illinois team will be conducting demonstrations of their technology using a sleeve of carbon fiber that lays flat – sort of like one of those finger traps you played with as a kid – but it’s made of carbon fiber that becomes the hardened reinforced structure later in the process,” Detor said.
The UIUC demonstration, conducted in partnership with Voyager Space, is planned for launch to the International Space Station aboard NASA’s Commercial Resupply Mission NG-24 in April 2026. The experiment will take place in the station’s Bishop Airlock module, where the team will test whether their materials and manufacturing process work in microgravity.
“If you want to construct a large structure in space, you don’t have a 100-meter autoclave you can put something into to heat it,” Detor said, adding, “Then they have a liquid monomer, which are molecules that have not polymerized, so they’re not solid yet. The chemistry of those monomers is really engineered for space launch – it’s got the shelf life you need and it’s able to survive the temperatures in space. The UIUC team has developed a unique way to trigger the polymerization, or hardening, chemical reaction. The process for most carbon fiber-reinforced epoxy, such as your skis or your tennis racket might be made of, involves bagging up the whole structure, infusing resin into the carbon fiber preform, and putting the whole thing into an autoclave to heat it up. If you want to construct a large structure in space, you don’t have a 100-meter autoclave you can put something into to heat it. So, they’ve developed what’s called a ‘frontal polymerization’ method, where you just ignite one end of the inside of the tube and the reaction self-propagates, stiffening the carbon tubes without heating up the whole structure. In theory, you could extend the process to produce very large structures once the polymerization process starts. You’d only be limited by the amount of feedstock coming into the process.”
Future Applications for Space Infrastructure
A third research team, based at the University of Florida, is not involved in the orbital demonstrations but is working on a separate project under NOM4D Phase 3. Their focus is on using lasers to bend metal in space, a process that could enable new fabrication methods for large structures. The team is collaborating with NASA’s Marshall Space Flight Center, which has experience in laser welding and cutting metals for space applications.
“The University of Florida is maturing the ability to bend metal using lasers and is working very closely with NASA’s Marshall Space Flight Center in Huntsville, Alabama, to share their learnings,” Detor said. “Marshall has a laser space processing portfolio for welding and cutting metals, and we recently visited their facility to show them the University of Florida work and add bending metal to the capability mix.”
The long-term implications of NOM4D’s in-orbit manufacturing technologies extend beyond scientific curiosity. NASA and private space companies are planning a future where construction takes place in orbit, whether for space-based antennas, solar power stations, or refueling depots. A key interest is space situational awareness, particularly in the cislunar region—the vast space between Earth and the Moon, where commercial and military activity is expected to grow.
“NOM4D aims to take the first small step to demo new technologies to see if in-orbit assembly of large structures is possible,” Detor said. “We’re paving the way for an in-space manufacturing ecosystem. If we’re successful, we can look forward to scaling up this kind of technology to eventually build space-based RF antennas with 100-meter or greater diameter that would significantly improve our situational awareness of activity in the cislunar region and beyond. We can also envision NOM4D technologies enabling other massive structures in orbit, such as refueling stations for commercial or government spacecraft, spaced-based solar array farms, and many other commercial and national security applications.”
Beyond national security applications, NOM4D’s technology could lay the groundwork for commercial infrastructure, including massive solar arrays to harvest energy or refueling stations to support long-duration missions. By demonstrating these technologies in space, DARPA is setting the stage for a future in which spacecraft are not just launched—but built—in orbit.
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