Between the end of the Space Shuttle program and the US budget sequester, it might look like NASA is scaling down. The space agency is making ambitious strides, however, in at least one technology – 3D printing. Along the way, the effect may be to revamp how we design big things and how we get those things running in space.
NASA thinks that 3D printing technology could transform space operations of the near and far future, and they’re
backing that belief with money. NASA just awarded a $500,000 contract to Tethers Unlimited (TUI) to demonstrate a robot-operated 3D printing system – SpiderFab – that could build large structures in orbit.
Conventional fabrication technologies work materials by cutting, shaping, and molding. In other words, they take unneeded material away. In contrast, 3D printing is an additive process. It works essentially like office (inkjet) printing, where a nozzle deposits ink at specific locations on the surface of a page under computer control. A 3D printer goes over the surface again and again, however, to build up an object with height as well as area.
It’s tough to pass a day without spotting at least one 3D story in the news – the technology has shown a terrific potential to reduce manufacturing costs and most industries that need fabrication – including NASA – are paying attention.
NASA recently tested a rocket engine made with nickel-chromium parts created via 3D printing. Early test data indicated that the new engine met all the performance specs of its conventionally-manufactured counterpart.
The agency is also involved with two space-based applications: manufacturing tools and food (yes, food) for astronauts.
NASA awarded Made In Space, a private company, a contract to put a 3D printer on the International Space Station (ISS) to produce replacement parts and tools, something that could reduce the amount of equipment that has to be planned, packed, delivered to orbit, and, of course, stowed for an entire mission. Why send equipment for every conceivable purpose when you can make what you need as conditions arise? Useful for ISS operations, the 3D printing concepts makes even more sense for longer space missions, where resupply might be out of the question.
Food production may be as close as a 3D printer gets to a Star Trek “Replicator.” It’s at the novel end of the technology spectrum, but nevertheless important to space operations. Most astronaut food is similar to military MREs (meals ready-to-eat), which can get boring fast. Anything that can make creative dishes can boost morale and health.
The culinary concept involves storing basic ingredients and additional nutrients in cartridges, and combining them under computer control to create better variety and nutrition. Need some new dishes? Just transmit some fresh recipes (programs) to the 3D printer. Storing raw materials separately and using them as needed can increase the shelf life of foodstuffs; no small consideration on longer voyages.
The biggest vision for 3D printing in space, however, and likely to be its “killer app,” is SpaceFab. The concept will enable structures designed for, and built in, the conditions where they’ll be used. Currently, products intended for space must be built on earth and delivered to orbit. This means they have to withstand earth gravity for construction, test, and storage, and then protected from vibration and acceleration for transport.
SpiderFab (planned for a demo by 2020) will “print” structures in the space environment. Only raw materials – requiring less stowage space and less transport care – need be sent from earth.
Dr. Rob Hoyt, CEO and Chief Scientist for TUI stated in a recent interview that “This radically different approach to building space systems will enable us to create antennas and arrays that are tens to hundreds of times larger than are possible now, providing higher power, higher bandwidth, higher resolution, and higher sensitivity for a wide range of space missions.”
In other words, this may be a chance to transform what’s possible in engineering things for space. By inserting a local, embedded manufacturing technology into the space environment, both design and fabrication concepts can be modified to exploit zero-gravity conditions, essentially bypassing many of the construction requirements forced by the transport of finished products and parts from earth. Parts can be bigger and more delicate. And scaling the size of structures (NASA proposes trusses up to a mile long) will scale their capabilities, as well.
Space manufacturing was a dream of the early Space Shuttle program. Some great advances were achieved in that era, but things never really flourished because the launch rate was never high enough and the per-pound launch expense was never low enough.
Maybe the next decade will show what’s possible with space construction. And, maybe, some of that experience may hold lessons for earth-bound engineering.