Enlarge / With extra-wide tracks and a bunch of different intelligent options, the Benthic Rover II can roam the seafloor for years at a time.
Madison Pobis | MBARI
The Benthic Rover II is the scale of a compact automobile, though it rocks fats treads, making it extra like a scientific tank. That, together with the 2 googly-eye-like flotation units on its entrance, provides it a kind of WALL-E vibe. Only as an alternative of exploring a garbage-strewn panorama, BR-II roams the Pacific seafloor, 13,000 ft deep. The robotic’s mission: to prowl the squishy terrain in quest of clues about how the deep ocean processes carbon.
That mission begins with a wild journey, 180 miles off the coast of Southern California. Scientists on the Monterey Bay Aquarium Research Institute decrease BR-II into the water after which … drop it. Completely untethered, the robotic free-falls for 2 and a half hours, touchdown on the abyssal plains—nice stretches of what you would possibly generously name muck. “It’s mushy and dusty at the same time,” says MBARI electrical engineer Alana Sherman, coauthor on a brand new paper in Science Robotics describing findings from the robotic’s adventures. “Which is part of the reason it’s a tracked vehicle, and it has these really wide treads.” That additional floor space distributes the robotic’s weight so it doesn’t sink into the sand.
If you needed to plot the right technique to torture a robotic, the deep sea can be it. At these depths the water is chilly, salty (and subsequently corrosive), and extremely pressurized; there’s an entire lot of liquid pushing down on the robotic.
Like the Mars rovers, this robotic have to be autonomous. In reality, in some methods it’s much more troublesome to maintain tabs on a rover 13,000-feet deep than it’s a rover on one other planet. Radio waves journey nicely in area, it’s simply that they take as much as 20 minutes every technique to make the journey between Earth and Mars—and good luck remotely piloting a rover in actual time with that form of delay. But radio waves hate water. So, as an alternative, BR-II makes use of acoustic indicators to speak to a different robotic, a floating glider that MBARI scientists launch from shore 4 occasions a yr. The glider, primarily a really costly surfboard, travels to the rover’s approximate location, pings it, collects standing updates and pattern information, and fires that data to a satellite tv for pc for the researchers to entry.
Enlarge / A rattail fish captured on BR-II’s digicam.
Enlarge / Notice the simplistic muckiness of the seafloor.
Since MBARI scientists can’t simply sit of their labs and pilot the rover, it’s by itself. But its directives are easy. Parked on the seafloor, it lowers two oxygen sensors into the muck. This provides the robotic a measure of the organic exercise within the sediment, as microbes devour oxygen and spit out carbon dioxide. The rover additionally has a fluorescence digicam system that casts a blue mild, which makes the chlorophyll in natural matter glow. This provides the robotic an concept of how a lot detritus from floor waters, often known as “marine snow,” is making its approach right down to the seafloor.
The rover sits in a single place like this for 48 hours, then strikes ahead 33 ft. That’s all. “It would not know if it drove off a cliff—all it knows is I’m supposed to drive forward 10 meters,” says Sherman. “But luckily, there are no cliffs around, so we take advantage of the simplicity of the environment to keep the robot more simple.”
Still, there’s an issue: the outsized treads make a large number of the seafloor. “Even though it is moving very slowly, it doesn’t take much to create this huge dust storm,” says Sherman. “We always want to be driving into the current so that it can push the sediment that is disturbed behind us.” So earlier than the rover strikes, it makes use of a sensor to get an concept of the present route of the … er, present, then heads straight for it.
The benthic rover does this for an entire yr, unsupervised: park, take measurements, transfer 33 ft, repeat. Then the scientists steam out of their analysis boat to provide it a battery change.