Tethers Unlimited expands to fulfill additive manufacturing orders

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SAN FRANCISCO — Tethers Unlimited, one of three companies NASA selected Dec. 7 to build a prototype space-based 3-D printer called FabLab has grown dramatically in recent years due to interest among government and commercial customers in this type of work.

NASA selected Tethers Unlimited of Bothell, Washington, Techshot of Greenville, Indiana, and Interlog Corp. of Anaheim, California, to build ground-based prototypes for machines capable of additively manufacturing items in orbit using a variety of materials. The space agency has earmarked a total of $10.2 million to the effort.

Through its Firmamentum division, Tethers Unlimited is involved in several related projects. NASA is paying the company to build Refabricator, a machine to recycle and reuse metal on the International Space Station, and to develop the Trusselator, a device to create lengthy carbon composite structures in orbit. Space Systems Loral hired Firmamentum to demonstrate how a small satellite could use the Trusselator to extend the distance between its antennas, sensors or solar arrays. For the U.S. Defense Advanced Research Projects Agency, Firmamentum is developing OrbWeaver, a small satellite to ride into orbit on an Evolved Expendable Launch Vehicle Secondary Payload Adapter ring, chew up the ring and turn the pieces into a satellite antenna.

“We decided to swing for the fences on that project,” Rob Hoyt, Firmamentum chief executive and chief technologist told SpaceNews.

Through each of these projects, Firmamentum is working to create a robust in-space manufacturing ecosystem, which is not easy since the raw materials are not readily available and there aren’t consumers in orbit clamoring for finished goods.

“At this point we are in a chicken-and-egg situation, so we are trying to work incrementally toward those goals,” Hoyt said in October at the Additive Aerospace Summit in Los Angeles.

 NASA is paying the company to build Refabricator, a machine to recycle and reuse metal on the International Space Station, and to develop the Trusselator, a device to create lengthy carbon composite structures in orbit. Credit: Tethers Unlimited
NASA is paying the company to build Refabricator, a machine to recycle and reuse metal on the International Space Station, and to develop the Trusselator, a device to create lengthy carbon composite structures in orbit. Credit: Tethers Unlimited

In spite of that conundrum, government agencies and companies are investing in the tools and technologies needed for on-orbit manufacturing.

NASA wants the technology for deep space exploration.

“When you think about going to Mars, you can either take all the spares you might need or make them along the way,” Raymond Clinton, who manages the science and technology office at NASA’s Marshall Space Flight Center, said at the summit.

Commercial satellite builders have a different imperative.

“They are running up on the physical limits of what they can pack into launch shrouds and onto launch vehicles but the demand for bandwidth is ever increasing,” Keegan Kirkpatrick, founder and chief executive of RedWorks Construction Technologies of Lancaster, California, said at the summit. “The only way to escape this trap is through in-space manufacturing. And they need this capability now.”

“There is serious interest, serious investment, serious effort to support in-space manufacturing of structures and system that stay in space,” said Ioana Cozmuta, who leads industry engagement and commercial space partnerships for the NASA Ames Space Portal of Moffett Field, California, an organization that promotes the commercial development of space. “I could see a lot of benefit not just from the technology perspective but from the cost and capability perspective.”

That interest has prompted Tethers Unlimited to grow from 14 employees in 2014 to 67 currently. Last year, the company doubled its office and lab space and “we are already busting at the seams,” Hoyt said.

Most of the growth is tied to in-space manufacturing work and small satellite components.

“The Swift software-defined radios have been our biggest commercial success,” Hoyt said, but business is also brisk for Hydros water electrolysis thrusters and Cobra gimbals for sensors and thrusters.

Ironically, the firm’s space tether business has not kept pace.

“We have delivered a handful of Terminator Tape deorbit modules, two of which are on orbit waiting for activation and several more planned for launch next year,” Hoyt said. “There has been very little research and development funding for space tethers over the past few years, so tether work has been relatively quiet.”

That may change, however, with NASA’s proposed Bi-sat Observations of the Lunar Atmosphere above Swirls mission led by NASA Goddard Space Flight Center, which proposes sending two cubesats equipped with imagers and spectrometers and joined by a 180-kilometer tether to gather data on the moon’s hydrogen.

In addition, Tethers Unlimited has a commercial spinoff for its tether development.

“We have a good business manufacturing precision-wound optical fiber spools for underwater communications and mobile robot applications,” Hoyt said. “That winding technology originated with NASA Small Business Innovative Research-Small Business Technology Transfer investments in space tether technologies.”
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