NASA just completed a test of an early prototype—maybe just an early, early precursor—space rover that may be flown to explore the Jupiter moon Europa. What's cool is that the rover is designed to float on the underside of the ice and "rove as if the underside of the ice is the ground." Up is down, down is up.
NASA says that it's the first time ever that an underwater, under-ice, untethered vehicle has been operated through satellite link. It's one of the cool technologies that can help us better understand the world we live in now while preparing us for exploration of future worlds.