When we talk about space exploration almost everything is a first. It’s easy to sound hyperbolic – the longest spacewalk, most time in space, first this, first that. But, it’s usually not exaggeration for impact. Almost everything that humankind does in space is a first – and the list of “firsts” is about to increase tremendously thanks to advanced manufacturing (AM). Space manufacturing is a reality that will propel us to new horizons.
In fact, AM will soon make exploration of the solar system possible by moving the supply chain from an Earthbound reality to one moored in orbit, or beyond. Space manufacturing’s lower costs, better materials, and faster repairs will all bring the rest of our solar system into reach.
NASA and other agencies have created a program to increase our ability to manufacture tools and replacement parts in space with AM methods at the forefront. Currently, when something breaks or a new tool is needed, it’s a long process involving barriers like scheduled launches, and weight or space payload limitations. It can take months to repair broken parts and the cost for repairs is exorbitant.
All of these challenges limit the ability for space exploration. However, AM methods can make exploration more feasible, especially if key parts of the supply chain can be moved beyond Earth’s atmosphere. If plans can be digitally delivered, and supplies reduced to base materials, AM can enable space exploration by shrinking timelines and budgets.
One company that is contributing to pushing what’s possible in space exploration is Tethers Unlimited, Inc. (TUI). TUI has developed technologies, including 3D printing systems that can recycle parts and remake them in space, and processes for the precision manufacturing of parts for the International Space Station, and has its eyes on using materials found in space to manufacture items needed by astronauts.
The GovDesignHub recently sat down with Robert Hoyt, CEO and Founder of TUI, to learn what is possible with AM and space manufacturing, and how the solar system will be reachable by humans in the not-too-distant future.
Here is what Robert had to say:
GovDesignHub (GDH): What does Tethers Unlimited do? And, what is your role in the organization?
Robert Hoyt: Tethers Unlimited is a company that I co-founded in 1994 that provides advanced technologies for space missions, including high-performance components for small satellites, space tether solutions for end-of-life deorbit, and robotics and tools for in-space services.
GDH: How can space manufacturing and AM and methods like additive manufacturing aid space flight and exploration?
Robert Hoyt: One benefit is being able to create parts and tools on-demand as the need arises. For example, on a manned mission to Mars, which might last two or three years, it’s impossible to predict which parts of the spacecraft might break and need to be replaced, and what tools the astronauts might need as they explore a new world. So, AM is ideally suited to creating the tools needed to explore the unknown.
Additionally, on spacecraft, the size of key subsystems – such as antennas, solar arrays, and telescopes – is currently limited by the size of the rocket used to launch the system. If instead, we can launch raw materials in a compact and durable form, along with 3D printers and other manufacturing tools, we can transform that raw material on-orbit into structures and build spacecraft with much higher performance – whether that’s measured in power, data rate, image resolution, or sensitivity.
GDH: What is the “FabLab?” And, what is the Tether’s “Refabricator?”
Robert Hoyt: FabLab is intended to be an integrated, in-space manufacturing system for the ISS and other manned space habitats. Its purpose is to enable on-demand precision manufacturing of mission-critical parts. To do so, it is expected to integrate tools for additive and subtractive manufacturing with inspection and testing systems, along with robotic aids for moving parts between stages of the manufacturing process.
The Refabricator is an experimental EXPRESS rack payload, about the size of a mini-fridge, that combines a plastic recycling system with a 3D printer. It was designed to perform an experiment in which plastic parts are printed, recycled, and then printed/recycled again for several cycles, in order to see how the plastic material changes over the multiple cycles.
Overall, the objective is to see how many times a plastic feedstock can be re-used in space. The motivation for this is to enable long-duration manned missions, such as a manned Mars exploration mission, to be sent with a small amount of plastic feedstock and an electronic library of all the parts and tools they might need, rather than having to send them with many, many shipping containers worth of every tool and part they might conceivably need.
GDH: Why is it important to be able to manufacture in space and on the ISS?
Robert Hoyt: Manufacturing on the ISS is really about proving out the tools and processes we need to enable exploration of the solar system. While the ISS is relatively “close” to the Earth, and emergency replacement parts could be delivered to it within a matter of a day or so if needed, delivering emergency supplies to a base on the Moon would take many days or weeks, and delivering supplies to a manned base on Mars could take many months or even years.
If instead, we can supply those exploration missions with the capability to manufacture mission-critical parts, we can send them designs within a matter of minutes and they can make them in situ. Ultimately, the benefits are improved safety and significantly reduced logistics costs for long-duration manned missions
GDH: How are new alloys and materials shaping what is possible? And, what will this make possible for space exploration?
Robert Hoyt: The manufacturing that has been done so far on the ISS has primarily used standard 3D printing plastics, such as ABS and Ultem. Those are useful for many applications, but they are limited in their strength and temperature tolerance. So, for key structural parts or mission-critical components, we will usually need higher strength materials such as metals.
Additionally, if we want to create really large structures, say to support a 30-m telescope that we could use to get images of exoplanets, we will need even higher performance materials, and materials with very low coefficient of thermal expansion (CTE) characteristics. Composite materials, such as carbon-fiber reinforced thermoplastics, are of great interest, and that is where we at TUI are focusing most of our efforts currently.
Eventually, we’d like to be able to integrate materials we can obtain in space – such as basalt from the lunar regolith – into these in-space manufacturing processes because that would enable us to affordably construct habitats and other infrastructure on the Moon and throughout the solar system.
GDH: What barriers need to be overcome to see AM become an integrated feature in space flight?
Robert Hoyt: First, we have to learn how to reliably process materials in the space environment. Materials behave differently in zero gravity and in vacuum conditions than they do here on Earth, so we have to experiment to figure out the right processing temperatures, processing times, and so on to be able to transform materials into products.
Additionally, we need to be able to verify that the products we make have the right shape and structural performance to serve their purpose, so we need to integrate metrology and non-destructive testing techniques into the process. And then we need to implement robotic systems that can take these products and integrate them into functional systems and spacecraft.
GDH: How are partnerships between private industry and NASA impacting opportunities?
Robert Hoyt: NASA, DARPA, and other government entities have made some collaborative investments with private industry to get the On-orbit Servicing, Assembly, and Manufacturing(OSAM)efforts moving, and that has led to several demonstrations on the ISS and ongoing efforts to fly several demonstration missions, such as OSAM-1, OSAM-2, and RSGS.
Moving forward, industry and government will need to work together to inject OSAM architectures into the trade studies for future mission architectures so that these AM and robotics solutions can start to make their way into operational missions.
GDH: What most excites you about AM and about your work with NASA?
Robert Hoyt: Currently, the whole supply chain supporting space missions is Earthbound, and that makes space missions very expensive and slow to accomplish.
If we can start to move some of that supply chain into space, we can dramatically reduce the cost of many missions and help to accelerate our exploration and development of the solar system.