Passage II

Aquatic Explorer AQUA2

[1]

Marine dives offer scientists invaluable chances to study sea life firsthand. (16)Yet the limited time divers may remain underwater-often no more than two hours-has led scientists to call for robots able to help conduct observations in an assistive capacity. Complex functions like detecting chemicals and mapping topography, and these have already been implemented in robots with wide success. The bigger challenge is teaching a robot to swim.

[2]

Powerful thrusters have helped some robots surge through the depths. Such equipment, however can alarm or even harm sea life. The engineers developing the robot AQUA2 imagined a robot able to use advanced imaging and electromechanical systems. To do so, it would need to swim as naturally as a fish, a squid, or-as it turned out-a turtle.

[3]

AQUA2 has also proved remarkably well adapted to land. Its flippers reverse direction in shallow water, pushing the robot up onto sturdy, arched legs. The legs (24) propel the robot out of the surf. Rubber treads on each leg allow AQUA2 to scale sand dunes or snowbanks, making the robot as suitable for studies in the Caribbean as well as those in the Arctic.

[4]

Like its biological counterpart, AQUA2 has flippers that allow it to glide through the water, dive to the ocean floor, and ascend from the bottom. Unlike thruster-powered robots, AQUA2 can make subtle changes in course simply by altering the positions of its flippers. By holding two flippers still, as it gently paddles, with the other four, for example, the robot can "hover" in place underwater. This exquisite competency will allow it to avoid disturbing the sea life it is designed to observe.

[5]

Now, AQUA2 faces a new challenge; even more tricky than reacting to different terrains is interacting with human divers. During field tests amid busy coral reefs in Barbados and the silty beds of lakes in Canada, AQUA2 practices following divers' instructions. Soon, scientists may be able to conduct more frequent, more efficient dives with robotic partners at their sides.