The colonization of the Moon and Mars is likely to be our first significant step outward into this Universe. It’s near, but not quite here, because there are numerous obstacles to overcome a complete list of them sitting before our eyes will make our heads spin.
One of these obstacles is our inability to construct structures in space. Certainly, our species has a real talent for assembling structures in space, but their component parts need to be made here on Earth, loaded onto a rocket, and then propelled to space for assembly.
It’s a method that works for now, but could prove entirely inadequate and costly for long-duration missions to the Moon and Mars. That’s why we need ways of utilizing the resources available on-site and the tools to bring them all together in shapes, objects, and structures we can utilize.
There are several projects currently investigating 3D printing as a method of building things in space (and by things, I mean anything from communication towers to habitats for astronauts), and that seems like a logical approach. But NASA, or more specifically its Ames Research Center, believes it has something superior up its sleeve: inchworm robots.
Okay, not solely inchworm robots, but a combination of that and structural building blocks plus intelligent algorithms.
You may not be aware of it, but NASA is operating something called the Automated Reconfigurable Mission Adaptive Digital Assembly Systems. That’s ARMADAS for short and it’s a project aimed at developing the hardware and software needed “to build functional, high-performance large-scale structures.”
In a nutshell, the idea relies on inchworm-like robots to assemble, repair, and reconfigure structural materials. It’s a piece of technology that could just as easily work on the lunar or Martian surface, in any orbit around a celestial body, and completely unsupervised by humans.
Inchworm robots are simple mechanical creatures that move by arching their backs. They are intended to operate in a structure lattice environment, each performing a specific task. However, their main objective is to use building blocks to form any structure envisioned by humans.
How is this supposed to work? It’s simple, really, and all one has to do is look at a laboratory demonstration performed at the Ames Research Center recently. For the experiment, NASA’s personnel used three of these autonomous robots and 3D building blocks NASA refers to as volumetric pixels (also known as voxels).
The voxels used in the demonstration were made of lightweight composite materials shaped like a cuboctahedron, a polyhedron with eight triangular faces and six square faces – as per NASA, they resemble a wire-frame soccer ball with flat faces.
The three robots utilized for the procedure had various tasks. Two of them moved on the exterior of the structure being built, transporting one voxel at a time, all the way from a supply station to where they needed to be placed. The third robot’s job was to secure each of the voxels to the rest of the structure.
During the test, all three machines operated independently and at the conclusion, NASA’s team was left with a structure of similar size to a shed. This structure was not flimsy, but rather comparable to high-performance structures like the trusses of the International Space Station (ISS).
The team behind this concept, who recently published their findings in Science Robotics, highlight several important aspects of using this technology.
Firstly, the robots used in this process are relatively simple. Inchworm machines can be easily constructed and their main task is to align each small step to a 3D grid. This means that they do not require complex computation or sensing abilities. They rely on pre-fed data and do not need machine vision or other external measurement technology.
Secondly, the size of the structures that can be built is virtually unlimited. The only limitation is the availability of building blocks.
Thirdly, there are no technical limitations on the types of structures that can be constructed. NASA’s team is currently working on expanding the library of voxel types to include things like solar panels, electrical connections, and shielding. This will enable the robots to know what to do next.
Lastly, structures built using this method can be disassembled and reconfigured into new designs, allowing for repurposing.
At present, ARMADAS robots are on the verge of gaining new abilities and features, such as inspection tools that could prove invaluable for future space missions. There is no specific timeline for when this technology will be applied in real-life scenarios, but it is expected to be a considerable amount of time.