Oceanography: R2DTuna
By Mark Wheeler

"Tuna are the fighter planes of the fish world," says Dave Barrett, a 35-year-old ocean engineer at the Massachusetts Institute of Technology. Hoping to put that power in a can, Barrett and his colleagues are creating a four-foot-long ocean probe patterned after the hard-swimming bluefin tuna. "Robotuna" has polystyrene ribs, spandex skin, and a computerized nervous system that controls 3,458 parts.

Plumbing the deep has long been limited by the expense of manned exploration. Hoping to economize, Barrett, with funds from the U.S. Navy, decided to build a $50,000 fish; he picked the tuna because it's had 60 million years to evolve a very spiffy propulsion system. Since any robot runs only as long as its batteries, Barrett hopes that by mimicking bluefin efficiency, Robotuna will get more bang from its 22 lithium cells, allowing remote-control navigators to keep it working underwater for up to six months.

For now, Robotuna swims only in a 110-foot-long test tank, tethered by an electric umbilical: The first outdoor splash will happen this summer in a saltwater pond. If everything works, Robotuna will be released next year to map the ocean floor, track schools of real fish, and flirt with a buoy or two before swimming home with a bellyful of data.