Galileo discovered Europa, Jupiter’s fourth-largest moon, in 1610. In 1977, the Voyager spacecraft buzzed past and we realized it was covered in ice. It took a few more years to understand that it also likely had unfrozen liquid water oceans. Kevin Hand, Deputy Project Scientist for the Europa mission at NASA’s Jet Propulsion Lab (JPL) explains how his team plans to launch a series of missions to orbit, land on, and hopefully explore the curious moon’s deep salty oceans with a self-driving space submarine. And Tom Cwik, manager for JPL’s space technology program, describes how he looks to Earth-bound submarines, ice drills and self-driving cars for inspiration of how to explore this distant world.