This May 2003 Scientific American article details how Hollywood filmmaker James Cameron and his brother Mike, an aerospace engineer, designed and built advanced untethered underwater robots that can maneuver and transmit video images from inside sunken shipwrecks, including the famous Titanic. Source: Scientific American, May 12, 2003
The Abyss Transit System
James Cameron commissions the making of robots for a return to the Titanic
By Gary Stix
At the beginning of the movie that made Leonardo DiCaprio a megastar, a camera-toting unmanned robot ventured into a cavernous hole in the wreck that sits on the bottom of the Atlantic, 12,640 feet from the surface. The 500-pound vehicle, christened Snoop Dog, could move only about 30 feet along a lower deck, hampered by its bulky two-inch-diameter tether hitched to a submarine that waited above. The amount of thrust needed to move its chunky frame stirred up a thick cloud. "The vehicle very quickly silted out the entire place and made imaging impossible," director James Cameron recalls.
But the eerie vista revealed by Snoop Dog on that 1995 expedition made Cameron hunger for more. He vowed to return one day with technology that could negotiate anyplace within the Titanic's interior.
In the past six months two documentaries--one for IMAX movie theaters called Ghosts of the Abyss, the other, Expedition: Bismarck, for the Discovery Channel--demonstrated the fruits of a three-year effort that Cameron financed with $1.8 million of his own money to make this vision materialize. The payoff was two 70-pound robots, named after Blues Brothers Jake and Elwood, that had the full run of two of the world's most famous wrecks, the Titanic and the Bismarck, which they visited on separate expeditions.
The person who took Jake and Elwood from dream to robot is Mike Cameron, James's brother, an aerospace engineer who once designed missiles and who also possesses a diverse background as a helicopter pilot, stunt photographer and stuntman. (Remember the corpse in the movie The Abyss, from whose mouth a crab emerges?) Giving the remotely operated vehicles freedom of movement required that they be much smaller than Snoop Dog and that the tether's width be tapered dramatically so as not to catch on vertical ship beams.
Mike Cameron took inspiration from the wire-guided torpedoes used by the military that can travel for many miles. His team created vehicles operable to more than 20,000 feet (enough to reach as much as 85 percent of the ocean floor). The dimensions of the front of the robot are 16 inches high by 17 inches across, small enough to fit in a B deck window of the Titanic. The bots have an internal battery so that they do not need to be powered through a tether. Instead the tether--fifty-thousandths of an inch in diameter--contains optical fibers that relay control signals from a manned submersible vehicle hovering outside and that also send video images in the other direction. The tether pays out from the robot, a design that prevents it from snagging on objects in the wreck.
James Cameron thought the project would be a straightforward engineering task, not much harder than designing a new camera system. "This turned out to be a whole different order of magnitude," he says. "There was no commercial off-the-shelf hardware that would work in the vehicles. Everything had to be built from scratch." If the team had known this early on, he added, "we wouldn't have bothered." Water pressure on the cable that carried the optical fibers could create microscopic bends in the data pipe, completely cutting off the control signals from the submersibles. Dark Matter in Valencia, Calif. (Mike Cameron's company), had to devise a fluid-filled sheath around the fiber to displace the minuscule air pockets in the cable that could lead to the microbending.
To save weight, the frame--similar to a monocoque body of a race car--was made up of small glass hollow spheres contained in an epoxy matrix. The thruster contained a large-diameter, slowly rotating blade with nozzles that diffused the propulsive flow, minimizing the churning that would otherwise disturb the caked silt. A high-resolution video camera, along with an infrared camera for navigation, was placed in the front of the craft along with three light-emitting-diode arrays for fill lighting and two quartz halogen lamps for spotlighting.
The winter of 2001 marked a critical juncture. It was six months before dives to the Titanic could be safely attempted, and James had to determine whether to proceed or wait another year. "Mike was really, really negative on the idea, but I decided to go for it," the director says. He felt he couldn't afford to wait longer and thought that a fixed deadline would focus the engineering staff at Dark Matter. For his part, Mike was contending with an unending series of design challenges. "It was such an overwhelming set of problems that I had very little confidence that certain parts would be solvable in the time we had," Mike says.
A few weeks before the dives commenced in the summer of 2001, the robots' lithium sulfur dioxode¿based batteries caught fire while being tested in a pressure tank, destroying what was to have been a third robot. Mike wanted to delay the dives, but James found a supplier of another type of lithium battery and pressed ahead.
At the dive site, Jake and Elwood took starring roles with their 2,000-foot tethers, exploring for the first time in about 90 years remote parts of the ships, including the engine room, the firemen's mess hall and the cabins of first-class passengers--even focusing in on a bowler hat, a brass headboard and an intact, upright glass decanter. The images lack the resolution and novel quality of the high-definition, three-dimensional IMAX images, the other major technological innovation of Ghosts of the Abyss. Jake and Elwood's discoveries, however, draw the viewers' interest because of what they convey of the Titanic's mystique. "You actually feel like you're out there in the wreck," Mike says. He remembers his brother piloting the robots with the helicopter stick that had been installed in the Russian submersible from which the robots were launched. "Jim ended up being a cowboy pilot," Mike says. "He was far more aggressive with the system than I was."
One scene in Ghosts of the Abyss reveals the tension that sometimes erupted between the brothers. James contemplates moving one of the robots through a cabin window that is still partially occluded by a shard of glass that could damage the vehicle or cut the data tether. When James declares that he is going to take Jake in, moviegoers can hear Mike pleading with his brother not to do it, ultimately relenting once the bot has negotiated the opening.
The decision to install a new type of battery at the last minute came to haunt the expedition; Elwood's lithium-polymer battery ignited while in the bowels of the ship. James manipulated the remaining robot into the Titanic to perform a rescue operation by hooking a cord to the grill of the dead bot and towing it out. At the surface--on the deck of the Russian scientific vessel the Keldysh, from which the two submarines carrying Jake and Elwood to the Titanic were launched--Mike rebuilt Elwood with a backup battery. During the next dive, the robot caught fire again while it was still mounted on the submarine, endangering the crew. Finally, Mike worked for an 18-hour stretch to adapt a lead-acid gel battery used for devices onboard the mother ship into a power source for Elwood, enabling the expedition to continue.
The bots, now fitted with a new, nonflammable battery that Mike designed, may find service beyond motion pictures. The U.S. Navy has funded Dark Matter to help it assess the technology for underwater recovery operations of ships or aircraft. The bots also have potential for scientific exploration of deep-sea trenches. After traveling to the Titanic and the Bismarck, the team went on to probe mid-Atlantic hydrothermal vents, discovering mollusks in a place where scientists had never encountered them before. As adventure aficionados, the brothers speculate that a descendant of Jake and Elwood might even be toted on a mission to Europa, one of Jupiter's moons, to investigate the waters that are suspected to exist below its icy shell. The Cameron siblings, who tinkered with home-built rafts and rockets as children in Ontario near Niagara Falls, hope to be around long enough to witness their robotic twins go from the bottom of the ocean to the depths of space.
Robot, Unmanned, Underwater, Bot, Deep Sea, Shipwreck, Titanic, Bismarck, James Cameron, Hollywood, “Titanic”, Mike Cameron, Engineer, Engineering, Tether, Cable, Camera, Image, Imaging, Video, Transmit, Battery, Internal, Fibers, Optical, Submarine, Submersible, Water Pressure, Documentary, “Ghosts of the Abyss”, “Expedition: Bismarck”, Scientific American