Robotic yellow submarine is 'Mars Rover of the sea'
By Ewen Callaway See a slideshow of images of the new sub Off the coast of Massachusetts’s Cape Cod on an unseasonably warm autumn day, something resembling a portly yellow dolphin turns on a dime before scooting off in the opposite direction. The nimble new automated sub, called Odyssey IV, is the baby of researchers at the Massachusetts Institute of Technology. It can plunge to depths of up to 6 kilometres to explore deep-water coral reefs, archaeological ruins and oil rigs. “It’s the Mars rover of the sea,” says Mike Soroka, a mechanical engineer at MIT, who helped develop the craft. “It’s the same kind of environment: unknown and unexplored, and potentially very useful to know about.” Unlike a few other autonomous underwater vehicles (AUVs), Odyssey IV can hover in place while it examines or interacts with objects, an ability that will let scientists do more than just sightseeing in the deep ocean. “There is a rich history of AUVs exploring the classical oceanographic features likes the deep sea vents,” says team leader Franz Hover. “What we’re doing with this vehicle is we’re seriously tackling the manipulation problem. It’s built for that. It’s what we’re supposed to do with the corals. It’s what off-shore industry wants,” he says. The new AUV could be seen as the opposable thumb of undersea research – a major step forwards in sub evolution. Odyssey IV’s belly is an empty shell that could potentially be filled with video cameras, chemical sensors, and hopefully even a robot-controlled arm. “The first task will be to grab something, anything,” Hover says. Another major challenge facing Odyssey IV’s developers will be piloting the craft at depths we cannot yet communicate with. The vehicle can be programmed to follow a set course, but its developers hope to develop software to make it more independent. In theory, Odyssey IV could be programmed to automatically recognise ocean features such as coral reefs, says Justin Eskesen, who leads software development on the project. The craft could also be programmed to perform a particular action once it spots what it is looking for, for example hovering in place and taking more pictures. Much of Odyssey IV’s hardware is far less revolutionary, making it relatively cheap to build. Its motors and thrusters come from companies that supply parts for less able commercial subs. Nearly a quarter of the 450-kilogram submarine’s weight is made up of tough borosilicate-glass balls that keep it buoyant. Those balls surround a beach ball-scale plastic sphere covering the sub’s “brain” (see an image) – a mass of wires, cables, circuits, pumps and a computer processor that is like that inside the $100 laptop designed for the developing world. Seawater is used to cool the collection. A second plastic sphere, beneath the brain, holds a collection of lithium-ion batteries like those inside laptops. They provide enough juice to run the robot for several hours. Tricks like using iron weights to sink the craft can extend missions to a dozen hours or more, Hover says. The new sub’s first scientific mission is likely to be sampling deep-water ocean corals, for chemical oceanographer Jess Adkins at Caltech in Pasadena. He hopes to use the chemical record of coral skeletons alive and dead to reconstruct ocean climate shifts. Initially, Odyssey IV will probably collect deep water corals with a net or sticky pad, but will later use a robotic arm to pluck them with mechanical fingers. Back near Cape Cod, the sub continues its acrobatics show, while its masters dream of new uses for it, not all of them likely to advance science. Collaborators in Cyprus are planning to soon build their own replica. “If they do, we will race them without question,” says Soroka, who is also interested in pushing his vehicle in other ways. “Barrel rolls?” he wonders out loud. Eskesen, the software developer and pilot, is already with him: “We could, in theory, do that.” The development of the sub was supported by the US government and MIT. Hover’s team has also received money from the oil company Chevron. See a slideshow of images of the new sub Mysteries of the Deep Sea -The deep sea is one of the harshest habitats on Earth, but is home to many remarkable creatures. Learn more in our comprehensive special report. Robots – Learn more about the robotics revolution in our continually updated special report. More on these topics: