Prototype platform proves capable of 3D printing PEEK up to 400°C under orbital conditions


Engineers from the University of Sydney and the University of Science and Technology of China have designed a 3D printer capable of processing high-temperature PEEK in simulated space conditions.

According to the team, using FDM 3D printing, it is possible to produce PEEK satellite spare parts in orbit, but the lack of heat transfer that occurs in space would cause current systems to overheat. To overcome this, the researchers developed a new 3D printer with Proportional Integral (PI) controllers capable of operating up to 400°C in vacuum, making it potentially ideal for future orbital repair missions.

A diagram of the orbital 3D printing system proposed by the researchers. Image via Advances in Space Research journal.

An enigma for the maintenance of satellites?

Over the past seventy years, the number of satellites in Earth orbit has skyrocketed, with more than 2,500 now straddling our planet’s atmosphere. As important as they are for communication and navigation on land, they are also vital for guiding space missions, so their failure has the potential to sidetrack those operations and create debris in which orbital vehicles can be damaged.

Theoretically, it is possible to prevent satellite failures from occurring by repairing them through “in-orbit manufacturing”. Considering this approach to be less expensive than launching rockets filled with repair materials into orbit, Northrop Grumman and DARPA are now working on missions, in which their respective “mission expansion vehicles” and “mission robotic vehicles” are ready. to conduct orbital tests.

However, the China and Australia-based researchers say the cost of in-orbit manufacturing is expected to climb further to $6.2 billion by 2030. To help aerospace companies reduce their spending in this area, the team therefore highlighted the success of 3D printing experiments. aboard the ISS, and suggested the technology could be deployed in space, as well as on manned spacecraft.

In particular, engineers believe that FDM machines could be ideal for performing orbital repairs, due to their lack of lasers, reliance on easily storable filaments, and compatibility with rugged materials such as PEEK. Yet despite their optimism around the technology, the team acknowledges that current systems would be vulnerable to material congestion in space, due to excessively melted filament.

The core tube design of the team's orbital 3D printer.
The core tube of the team’s orbital 3D printer (pictured) is designed to prevent blockages at high temperatures. Image via Advances in Space Research journal.

Print in the vacuum of space

To make orbital 3D printing more viable, researchers set out to develop a 3D printing system with an improved thermal control unit that could land on satellites, before using robotic arms to replace damaged parts. Besides these arms and its landing gear, the team’s first prototype was largely based on a standard FDM architecture, with heating bar, block, sink, strap, extruder and radiator.

In order to assess the potential of their machine before building it, the team chose to perform several PEEK printing simulations. Interestingly, the results showed that increasing the amount of thermal straps between the device’s heatsink and radiator allowed it to more effectively control the temperature of its core tube, while preventing backflow of molten filaments during material feed.

Through their simulations, the engineers also discovered that printing in reduced gravity can cause material to attach to the inner tube of a system, increasing friction and potentially creating extrusion blockages. To work around this problem, the team iteratively modified this section, before coming up with a design that served to improve its heat conduction efficiency and operated at heat up to 400°C.

Finally, once they gathered all their data, the researchers designed a mathematical model, which demonstrated the benefits that introducing a “fuzzy PI control module” would bring to their system. Essentially acting as a failsafe, the device is designed to trip at temperatures of 380°C, improving the accuracy of its thermal control functions, but also preventing overheating and the risk of repair errors.

Having completed their evaluations, engineers are now building a working prototype, which they intend to test in a physical vacuum chamber. In the future, if their printer were to find end-use applications, the team believes it could help “reduce the cost and time of space exploration” by performing repairs “without the need for launches.” additional”.

The Redwire Regolith Print Facility Suite, consisting of Redwire's additive manufacturing facility, as well as lunar regolith simulation printheads, plates and feedstock that will be launched to the International Space Station.  Photo via Redwire.
Redwire has now installed several 3D printing equipment aboard the ISS, including its Regolith Print facility (pictured). Photo via Redwire.

Ambitious orbital applications of AM

3D printing in space might sound like something out of science fiction, but the technology has already been tested off-planet, aboard NASA’s International Space Station (ISS). One of the leaders in this field is Made In Space, now a subsidiary of Redwire, which last year installed a new ceramic 3D printing module on board the orbital base.

The company’s technology is also set to be installed on Blue Origin and Sierra Space’s upcoming “Orbital Reef” commercial space station. Scheduled for launch by 2026, the new base is expected to serve as a “mixed-use business park,” while hosting Made In Space’s ongoing microgravity R&D and experimental production testing.

Meanwhile, at Munich University of Applied Sciences, researchers have taken a similar approach to the Australian-Chinese team and developed an orbiting satellite 3D printer. Designed to reduce the amount of mission-limiting fuel needed to fire repair equipment into space, the system may in the future be able to build entire solar arrays or antenna-related parts in weightlessness conditions.

The researchers’ findings are detailed in their paper titled “Design by extrusion and thermal control of a 3D printing platform in orbitwhich was co-written by Jianning Tang, Trevor Hocksun Kwan, and Xiaofeng Wu.

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Featured image shows a render of a satellite in Lower Earth Orbit (LEO). Image via Made In Space.


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