As future locations to explore in our solar system, some particularly exciting options are worlds with subterranean oceans. Places like Saturn’s moon Enceladus and Jupiter’s moon Europa are both believed to harbor liquid oceans beneath thick icy crusts, making them intriguing places to explore and even search for possible evidence of microbial life. But how do you design a robotic system for exploring an icy ocean on a distant moon?
One idea from NASA’s Jet Propulsion Laboratory is to use a swarm of tiny swimming robots, working together in a concept called Sensing With Independent Micro-Swimmers (SWIM). These robots, which NASA describes as the size of a cell phone and wedge-shaped, can be carried in a group by a single probe and thus take up very little space in a spacecraft. The probe can then make its way through the icy crust by melting it away, and the robots are released into the water.
“My idea is, where can we take miniaturized robotics and apply them in interesting new ways to explore our solar system?” the originator of the idea, Ethan Schaler of JPL, said in a pronunciation† “With a swarm of small swimming robots, we can explore a much larger volume of ocean water and improve our measurements by having multiple robots collect data in the same area.”
The robots would communicate with the probe, which would remain connected to a lander on the surface via a physical chain. That means the evidence wouldn’t be able to move much, so the robots could explore instead.
“What if, after all the years it took to get into an ocean, you get through the ice shell in the wrong place? What if there are signs of life there, but not where you entered the ocean?” said SWIM team scientist Samuel Howell. “By bringing these swarms of robots with us, we could look ‘there’ to explore much more of our environment than a single cryobot would allow.”
Having multiple robots would allow them to cover and explore more parts of the ocean, but it has a function that is even more important. It reduces the risk, if one or more robots are destroyed, the mission can continue without them. This is especially valuable when exploring a new environment for the first time, as it is extremely difficult to predict the dangers there will be for explorers there.
The SWIM concept has recently been honored for further development under NASA’s Innovative advanced concepts (NIAC) program.