How NASA is developing swimming robots to look for alien life

Some day within the future, a swarm of cellphone-size robots could swim through the water beneath the kilometers - thick icy shell of Jupiter’s moon Europa or Saturn’s moon Enchiladas, trying to find alien life. These robots might be packed within narrow ice-melting probes that would tunnel through the frozen crust to release the tiny robots underwater, which may then swim far and deep to learn about the new worlds. Or a minimum of, that's the vision of Ethan Schaller, a robotics engineer at NASA’s Jet Propulsion Laboratory (JPL) in Southern California. Schaller’s Sensing With Independent Micro-Swimmers (SWIM) concept was recently awarded $600,000 in phase II clinical trial funding from the NASA Innovative Advanced Concepts (NAC) program. Schaller and his team will use the funding to form and test 3D-printed prototypes over the next two years. SWIM’s early-stage concept envisions wedge-shaped robots, each about 12 centimeters long and 60 to 75 cubic centimeters in volume. They're designed so that about four dozen of them could fit in a iRobot (ice-penetrating probe) 25 centimeters in diameter, taking over just 15 per cent of the science payload volume. This is able to leave more room for more powerful but less mobile science instruments that could gather data through stationary measurements of the ocean. Each robot would have its own system, onboard computer, and ultrasound communications system, together with sensors for temperature, salinity, acidity and pressure. A  Phase II clinical trial of the study will also add chemical sensors to monitor for biomarkers. NASA’s Europa Clipper mission, planned for a 2024 launch, will do multiple flybys of Jupiter’s moon to collect detailed data with a large suite of instruments when it arrives there in 2030. iRobot, concepts to research such ocean worlds are being developed through NASA’s Scientific Exploration Subsurface Access Mechanism for Europa (SESAME) program, also as through other NASA technology development programs. The iRobot that deploys the swimming robots would be connected to the surface-based lander through a communication tether. The surface-based lander, in turn, would be the purpose of contact with mission controllers on Earth. This tethered approach means the iRobot would probably be unable to venture much beyond the point where ice meets the ocean.   Also, the iRobot will have a nuclear battery, which it'll rely on to melt a downward path through the ice. Once within the ocean, that heat could create a thermal bubble, slowly melting the ice above and causing reactions that would change the water’s chemistry. SWIM would allow the gathering of data far away from this. Further, the SWIM robots could mimic fish and birds to “flock” together and take overlapping measurements to scale back errors in the data. This group data could also show gradients: temperature or salinity. For instance, the swarm’s collective sensors might be used to identify the source of a temperature or salinity change and point in that direction for further exploration. “If there are energy gradients or chemical gradients, that’s how life can start to arise. We might need to get upstream from the iRobot to sense those,” said Schaller during a press statement.