In the near future, a rover lands near a rocky field on Mars. The area is too chaotic to navigate. Suddenly its doors open and four robots emerge, moving not like a standard rover but like snakes across the landscape. The snakes crawl over rocks, through narrow spaces, and into crevices. Their camera-eyes see. Their chemical detectors smell. When a snake comes across a deep hole leading underground, it slithers into the gap, and then backs out. Another snake moves like a sidewinder up a sandy hill.
With the day's exploring over, all four snakes return to the rover and crawl all over it, making repairs. When everything is shipshape, the snakes crawl back into their dens. The rover rolls on to the bottom of a rocky hill. Tomorrow the snakes will emerge again, sending data back to the rover.
The stuff of movies? The European Space Agency (ESA) says it's the future of space exploration and the beginning of applications on Earth like hunting for earthquake victims or exploring now-inaccessible underground formations.
When it comes to snake robots there are serious questions. How can a long, thin, computerized snake slither across a surface? How does it gain traction? How does it move through sand or liquid? How can it move across the surface of a comet with its razor-sharp edges? Those are engineering questions that have the ESA intrigued and working.
A while ago Robotnor Centre for Advanced Robotics in Norway built a hydraulic robot snake called Anna Konda. The snake was developed in response to fires in Trondheim after safety officials asked for a firehose that could navigate through the chaos of a burning building. Anna Konda and its newer sibling Mamba both were developed to figure out how to grip a surface as it moves in a serpentine motion forward and backward and sideways. On earth, these snakes would crawl into gas pipes, swim under an aircraft carrier, or slither though hard-to-reach industrial areas for repairs.
But the ESA sees a more celestial use for these sensate pythons. They established SERPEX, Serpentine Robots for Planetary Exploration, and funded prototype development of snakes at companies like Norway's SINTEF institute.
There, a biomimicry group first developed Aiko to solve the complex issues of movement. The snake robot Weeko is a more recent improvement. One goal of the Norwegian company is to place snakes on the ISS to inspect, report, and maintain the station.
Current technology now envisions that these snakes will be tethered to a rover or a spaceship. This solves the problem of powering the narrow and perhaps even short linear robots. The next step would be to create self-propelled snakes, perhaps with nuclear power.
The rover Spirit got stuck in soft sand of Mars. In the future, a rover could release snakes that would find a way to get it moving again. The Philae lander on the comet 67P/Tsjurjumov-Gerasimenko was unable to deal with the craggy terrain, a snake could have make things right.
The ESA is counting on the Norwegian teams to build robot snakes and one day they may change the way we explore space or fix things on earth.
