This five-and-a-half-foot robot jellyfish could be the future of Navy underwater surveillance. Seriously. Maybe. Certainly, if a team of engineers from Virginia Tech gets its way. Meet the Cyro, an autonomous robot with eight mechanical legs ringing its metal chassis, designed to mimic the unique, efficient underwater propulsion of a jellyfish. Covered in silicone to replicate the jellyfish's wavy, bioluminescent mesoglea - the jelly, basically - the Cyro weighs a staggering 170 pounds, all thanks to a five-year grant from the Office of Naval Research. The robot is still a prototype, years away from being in the water. But it represents a new kind of testbed for oceanographic surveillance, the Cyro's basic application. Like the bird- and insect-shaped drones the Air Force is developing, a jellyfish-like spybot has a natural stealth advantage. "Mimicking a natural animal found in a region allows you to explore a lot better," says Alex Villanueva, a graduate student at Virginia Tech working on the Cyro.