Tethers Unlimited Inc. says it’s delivered a combination 3-D printer and plastic recycler to NASA for testing on the International Space Station.

Tethers Unlimited CEO Rob Hoyt told GeekWire that the Refabricator payload, about the size of a mini-refrigerator, was built under the terms of a $2.5 million Phase 3 contract from NASA’s Small Business Innovation Research program, or SBIR. It’s on its way to NASA’s Kennedy Space Center in Florida and is due to be sent to the station on a SpaceX Dragon resupply flight later this year, Hoyt said in an email.

The formal delivery to NASA marks the culmination of three months of performance and certification testing both at Tethers Unlimited’s lab in Bothell, Wash., and at NASA’s Marshall Space Flight Center in Huntsville, Ala., the company said today in a news release.

“It took a lot of dedication and many long hours by our team to iron out all the challenges associated with creating a highly automated recycling and manufacturing system for use in space, and the guidance of NASA’s In-Space Manufacturing Program was invaluable to getting through the certification process,” Hoyt said. “We can’t wait to get this up on the ISS and start demonstrating capabilities for sustainable manufacturing in space.”

The Refabricator uses a process called “Positrusion” for recycling plastic parts into fresh filament for 3-D printing.

“Traditional plastics recycling and 3-D printer filament manufacturing techniques involve grinding and extrusion steps that could pose safety concerns on the ISS and often require a lot of adjustment to keep them running reliably,” Hoyt explained.

“To create a recycling system that is safe and doesn’t demand a lot of astronaut time, we developed a new method for recycling plastic parts into 3-D printer filament, and integrated it together with a 3-D printer to create a highly automated recycling-and-manufacturing system,” he said.

Hoyt said the process turns out plastic filament that’s extremely consistent in its composition, which should result in high-quality 3-D-printed parts.

“From here, we still have a lot of paperwork to finalize, and the staff members who will be operating the system remotely will go through the formal training needed to qualify them to operate equipment on the ISS,” Hoyt told GeekWire.

“The Refabricator will primarily be used to print ‘dogbone’ samples that will be used to study the changes in the plastic material (strength, elasticity, etc.) as it goes through multiple recycling/printing cycles,” he said.

Tethers Unlimited is working on another NASA-funded project known as FabLab, which is aimed at developing a more advanced in-space fabrication facility. FabLab should be capable of manufacturing and recycling 3-D-printed items produced from a variety of materials, including metal as well as plastic.

NASA has set aside $10.5 million for the prototyping phase of the FabLab project, which involves Tethers Unlimited as well as California-based Interlog Corp. and Indiana-based Techshot. After the prototype is delivered, NASA will select partners for further development of the technology.

Additive manufacturing is expected to play a big role in future space exploration. Rather than carrying all the spare parts and tools that may or may not be required for a long-duration mission, astronauts could manufacture what they need from feedstock.

The first 3-D printer designed for use in space was built by California-based Made In Space and sent to the space station in 2014. This month, Made In Space announced that it has secured a NASA SBIR Phase 2 contract for further development of its next-generation Vulcan hybrid manufacturing system.

The Vulcan system is designed to fabricate precision parts made of aerospace-grade metals such as titanium and aluminum, as well as plastic parts and hybrid components made from combinations of materiais.

NASA also has invited Made In Space to submit a proposal for a technology flight demonstration mission of its Archinaut technology for building large structures in space. The development team also includes Northrop Grumman for systems integration and avionics work, and Oceaneering for robotic capabilities.