In 2015, NASA awarded Washington-based technology firm Tethers Unlimited, Inc. (TUI) a Small Business Innovation Research (SBIR) grant to continue developing its Positrusion Recycler, which recycles plastic waste into 3D printable filament, for use aboard the International Space Station (ISS). NASA was pleased with the direction the technology was going, and last summer gave a Phase III SBIR to TUI division Firmamentum to create a 3D printer/recycler combo for the ISS, an experiment in closed-cycle manufacturing in outer space called the Refabricator. The machine, which is the first to combine 3D printing and recycling in one device, is about the size of a mini fridge, and is able to melt down a plastic component and print out a brand new component from the same plastic.
According to NASA, it costs $10,000 to launch one pound of payload into Earth’s orbit, but the agency is working to reduce this cost. Next spring, the Refabricator will be sent up to the ISS and be used to recycle, then 3D print with, plastic in outer space. Not only will this save on payload launch costs, but the Refabricator will also help make space a zero-waste zone. But the ultimate destination goal for the machine is somewhere farther than the ISS: the Moon and Mars.
Niki Werkheiser, who specializes in in-space manufacturing at NASA, explained, “That’s a very different model.”
It only takes a few hours for a resupply mission to reach the ISS, while it would take weeks to send new supplies to the moon…and months to get to Mars.
Last year, Jesse Cushing, Principal Investigator for the Refabricator project, said, “On a manned mission to Mars, the astronauts must bring everything they need with them. Due to the incredibly high cost of launching mass to Mars, carrying every tool or replacement part that they might possibly need simply isn’t affordable. The Refabricator will demonstrate the ability to recycle plastic parts and waste to make new parts and tools on-demand. This capability will enable the astronauts to use material that would otherwise be waste to maintain their spacecraft and adapt to unforeseen challenges on the Martian surface.”
For years, NASA has wanted to use 3D printing technology to reduce the cost and weight of supply payloads sent to space, and even tested a 3D printer on the parabolic KC-135A ‘Vomit Comet‘ aircraft in 1999 to see how gravity changes would affect the process. But Werkheiser explained that 3D printing patents “made doing things with the technology more complicated,” so the first 3D printer in outer space, developed by Made In Space, didn’t arrive aboard the ISS until 2014, and the second printer, Made In Space’s Additive Manufacturing Facility, was launched last year. But even though the zero-gravity 3D printers help astronauts make their own tools and medical supplies in space, it still costs a lot to launch fresh plastic to space.
Werkheiser said, “If you have to launch all of the raw feedstock, how is that really helping?”
This is a good point…and one that the Refabricator’s recycling capabilities are helping to solve. Plastic recycling usually involves pulverizing the raw material into a powder, which TUI’s research and development leader Rachel Muhlbauer compared to a coffee grinder; then, a different machine turns the powder into new base plastic. But in space, powder is very dangerous for astronauts, due to the lack of gravity – so the Refabricator melts the plastic into filament base material. Not only does this eliminate the issue of powder in space, this method causes less damage to the plastic, so it can be used multiple times without having to “be diluted by fresh, non-recycled plastic.”
But the Refabricator machine avoids this issue entirely.
Muhlbauer explained, “A lot of the terrestrial ways of making filament generates a lot of waste.”
“You put the material in and you get that material right back out,” Muhlbauer said.
The controlled environment aboard the ISS also saves the Refabricator from a big hassle that comes with recycling plastic on Earth – sorting. Different flavors of plastic, like milk jugs and the compound in shopping bags, have different behaviors during the recycling process here, so they have to be sorted into general categories first, and even then there are batches that must be abandoned due to contamination. On the ISS, the Refabricator only works with sturdy Ultem material, though the sorting problem will become an issue once more recycling flavors are introduced in space.
That’s why NASA’s next goal is to incorporate HDEP, a type of plastic that can be used for medical purposes. Werkheiser is also hoping that proposals to the FabLab project will, at some point, figure out how to mix plastics with metal, and potentially even electronics printing. The FabLab will be building on the tests currently being run by Werkheiser’s team on the Refabricator before it’s launched next year.
According to Werkheiser, the Department of Defense is taking an interest in NASA’s work with the Refabricator, as US troops often work in small spaces and have to deal with safety concerns, limited skill sets, and tight project timelines.
Muhlbauer said, “All those things that we are designing to make it perform on station in a safe way only makes it safer on the ground.”
The Refabricator is fairly autonomous, and will be completely run by technicians on Earth, so astronauts don’t have to waste valuable time watching the machine work; instead, they’ll only have to remove new products from the machine once they’re complete. Discuss in the NASA forum at 3DPB.com.[Source: Newsweek]