Why Does the Navy Need a Giant Robotic Jellyfish?

At the end of last week, a team of Virginia Tech researchers revealed the first look at a hefty new robotic jellyfish that it's building for the U.S. Navy. This is not the Navy's first robotic jellyfish. A year ago, America learned about the descriptively named Robojelly, a self-charging blob-bot built by the same team hailed or its deceptively natural-looking ability to swim through water and morph into new shapes much like a real jellyfish. Ultimately, it's supposed to be equipped with a stealthy engine that sucks hydrogen out of the water around it for fuel. The new robot is a lot like the old robot but bigger.