2. Build Better Robots

Louis Whitcomb, professor and the Louis M. Sardella Faculty Scholar of Mechanical Engineering, is helping to create that all-important “before” picture in a different way: through improving the robotic vehicles that offer one of the few ways for researchers to explore the deep ocean.

When Whitcomb first heard about the Deepwater Horizon spill, he knew that such robots, known in the business as remotely operated vehicles (ROVs), would be involved in investigating the disaster and helping to fix it. Since the 1980s, ROVs have been oceanography’s go-to tool for exploring the deepest depths of the world’s oceans and sampling geology and sea life. These machines are also a must for deep water oil drilling, which generally takes place at depths of 1,000 feet or more, at pressures that can easily crush an unprotected human.

“These extreme environments won’t support human life,” says Whitcomb, who directs the Whiting School’s Laboratory for Computational Sensing and Robotics. “The Deepwater Horizon well is at almost a mile of depth, far below the depth you could use any human diver. ROVs are the only practical and safe means of getting to the wellhead.”

After the Deepwater Horizon oil rig sank, its owners and operators mobilized a fleet of oilfield service-and-supply vessels under contract. Each of these vessels carries a couple of ROVs that dock inside metal hangars, with long cables attached to lower the robots to the ocean floor. Each ROV (about the size of a minivan) is equipped with cameras to get a 360-degree view. Its two robotic arms are controlled by a human operator, who sits comfortably above the water’s surface in a control room. The images from the cameras and the commands from the human controller travel through a tether that stretches from the ship down to the robot.

Through such tethered ROVs, BP’s cleanup crew collected all the images of Deepwater Horizon’s broken riser pipe spewing oil into the water. Though this setup is fine for maintaining an undersea oil well or even taking small exploratory jaunts on the ocean floor, it severely limits the expansive exploration necessary for getting a topographically accurate map of the sea floor or a complete census of sea life—two steps toward understanding the undersea environment in advance of drilling or trying to mitigate a major oil-related disaster.

“It’s a fact of life that drilling in the ocean will continue in my lifetime—I don’t have any illusions about that,” says Whitcomb. “We need better technology to extend scientists’ hands, eyes, and ears to probe these environments and do ongoing assessments where we’re mining oil, gas, and minerals from the sea floor.”

The need for better tools to more precisely measure the outflow rate from leaking undersea wells became strikingly apparent in the early days of the Deepwater Horizon spill. BP initially estimated that only 1,000 barrels of oil were leaking from the wellhead per day, though many experts immediately suggested that the flow could be much greater.

Responding to a call from the U.S. Coast Guard for new ways to estimate the flow rate, Whitcomb and colleagues from Woods Hole Oceanographic Institution, MIT, and University of Georgia developed a plan. The researchers came up with a novel system that combined imaging sonar, lasers, and Doppler sonar—one of Whitcomb’s areas of expertise—and loaded these different instruments onto an ROV that dived down to the wellhead. Their estimate of 60,000 or more barrels per day was substantially higher than those from other groups. Eventually, that estimate ended up coming close to the official United States Geological Survey estimate of 53,000 barrels per day.

Whitcomb and his colleagues hope to continue to develop new methods to measure more precisely fluid flow rates in the deep ocean. Besides gauging oil well leaks, these methods might also be employed to precisely measure the fluid outflow of deep-sea hydrothermal vents, a boon to ocean science.

Moreover, Whitcomb and his team at Hopkins (with colleagues at Woods Hole) are hard at work developing the next wave of robots: untethered autonomous underwater vehicles, or AUVs. These operate on battery power and receive a series of commands to execute—much like the Mars Rover. They can cover a much larger area than tethered ROVs, ranging tens of kilometers away from a surface ship.

“All the work we’re doing is directly applicable to understanding the effects of normal large-scale industrial operations in the deep ocean—and abnormal operations as well—by developing better tools for ocean science,” says Whitcomb.

In late July, Louis Whitcomb and colleagues submitted their final report on the outflow rate of the Deepwater Horizon oil spill to the U.S. Coast Guard. According to Whitcomb, although the team’s final version included more details about their methods and more refined numbers, their initial estimate of flow rate was right on target.