Robots of the Deep Blue Yonder

PS: There are no rudders, so how does the glider steer?




CJ: Basically, we're shifting the battery pack around to control the steering and the flying. It's kind of like flying a hang glider. The battery can move side to side, or fore and aft to give you some pitch control.




PS: What happens if it bumps into something?




CJ: We tend to be in deeper water, so we don't really worry about the bottom. And it's a rather slow-moving vehicle. It travels at a horizontal speed of about 1 knot. So if you hit something, you're just kind of going to bounce off it and keep on marching.




PS: What kind of information does it pick up along the way?




CJ: The salinity, temperature, density of the water at different depths. You could have a fleet of gliders just running back and forth across the Atlantic Ocean. This could give you an idea about global warming.




PS: How is this better than current measurement techniques?




CJ: With acoustic tests, you're making sounds and listening to them a couple thousand kilometers away, giving you an idea of the temperature because it directly affects the speed at which the sound travels. But what's missing is something marching back and forth in between, which would give you an idea of the density of the water at different points. So our gliders would certainly complement that kind of experiment. And it wouldn't cost $25,000 to $40,000 a day, like a research vessel.




PS: So for how long could the gliders run?




CJ: Because the thermal cycle does your propulsion, you can think of operating them for as long as four years. The batteries don't have to provide the buoyancy drive. They're simply running the communication, the data collection and the navigation.




PS: Speaking of which, how does the glider send its data back?




CJ: It's an autonomous vehicle, so it's down there flying a mission without communicating with us. But as it comes to the surface it gets GPS-fixed for its navigation and it calls in-if we're close enough-through a radio-frequency modem link. It says, 'Here's the latest information, and if you wish you can send in a new set of mission instructions.'




PS: What's next?




CJ: We're slated to leave on the tenth of January to run thermal glider trials in the "tongue of the ocean," or TOTO, off the Bahamas, with the Woods Hole Oceanographic Institute and the University of Miami.