Kevin D. Jones/NPS
Submarine hunting just got more deadly.before taking off vertically to hunt in flocks could soon be used by the US Navy.
Sonar systems are used to search for submarines. For example, buoys that use them – commonly called sonobuoys and first developed in the second world war – scan for submarines with sonar just below the surface. Dropped from aircraft, sonobuoys are still a mainstay of submarine hunters. But once deployed, they only work for a few hours before their batteries run out or they drift out of range.
The Aqua-Quad, built by Kevin Jones and his colleagues at the Naval Postgraduate School in Monterey, California, does not have such limitations. The drone looks like, but might better be described as a sonobuoy that spends some of its time in the air. “It’ll be on the water 23 hours a day, and flying maybe one hour a day,” says Jones.
Not only can the drone fly itself wherever it is needed, but its wings double as solar cells that provide unlimited power. In addition, the Aqua-Quad takes off and lands vertically, which means it can handle rough seas., but these can run into trouble in bad conditions.
When the wind is too strong to fly at all, the Aqua-Quad can ride out a storm on the surface. The team is working on a self-righting mechanism to let the drone recover after capsizing.
Roaming and flocking
In theory, the drone could roam the oceans indefinitely, says Jones – at least until algae or salt-encrustation disables the rotors or solar cells. “We wanted to make something tough enough to survive out at sea for some length of time,” he says.
Another advantage that drones have over sonobuoys is that they can hunt as a flock, arranging themselves into a line or grid to cover a wide area.
The Aqua-Quad shares several features with another marine drone called CRACUNS (corrosion resistant aerial covert unmanned nautical system), which was developed by a team at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland (see video below).
CRACUNS is not solar-powered, but can hide beneath the surface of the water and then launch itself straight up into the air from several metres down.
Both drones can carry a range of sensors – also making them useful for, or for tracking marine animals, says Jones.
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