The Navy's next wave of robots will take on one of the most dangerous missions on the open water: destroying mines.

Anti-mine warfare is a critical mission for the Navy, as nations like Iran can mess with the global economy just by threatening to plant mines in crucial commercial waterways. But the tools that the Navy has to disable mines have a crucial weakness: they depend on humans getting too close to them for comfort. When it comes to blowing up, or "sweeping" mines, explains Navy Capt. Duane Ashton, "There's a saying: 'Hunt if you can, sweep if you must.'"

Ashton, the Navy's program manager for its seafaring robots, has a different idea: Let the robots do the dirty work. By April, he tells Danger Room, he hopes to solicit defense contractors to build something called the Unmanned Influence Sweep System, or UISS, a robotic ship charged with speeding out into suspected minefields and essentially fooling them into detonating them before they come in contact with a ship full of sailors. If the UISS works as intended, it'll be part of a fleet of near-future Navy robot ships and subs designed to neutralize some of the most immediate threats on the high seas.

The idea is to launch the UISS from a Littoral Combat Ship, the new close-to-shore fighter that the Navy wants to be the mine-stopper of the future, among its other missions. Currently, minesweeping is a task for manned ships and helicopters like the Avenger-class mine countermeasures ship and the MH-53 helo. "This would be the first unmanned sweep system [for a] surface capability," Ashton says, something "a lot of countries are looking at" but none have yet succeeded in developing. It works by playing a kind of practical joke on a minefield.

The Navy's prototype of its desired Unmanned Influence Sweep System, a robot ship that will blow up acoustic or magnetic undersea mines. Photo: U.S. Navy The Navy's prototype of its desired Unmanned Influence Sweep System, a robot ship that will blow up acoustic or magnetic undersea mines. Photo: U.S. Navy

Underwater mines don't necessarily need to detonate on contact with a ship. Many explode when they sense the acoustic sounds that ships give off when passing through a waterway, or by detecting the magnetic signatures of the metals used to construct ships. So the UISS spoofs those acoustic and magnetic signals, getting the mines to "wake up," in Ashton's phrase – that is, detonate – well out of range of a Littoral Combat Ship or other Navy ship charged with keeping waterways mine-free. In 2011, testing in the Florida waters with a 40-foot, remote-controlled UISS prototype proved that the robot's joke could get the mines to explode far from any sailor. Last week, in a much-anticipated step ahead of the UISS solicitation, the Navy asked defense companies for their feedback on constructing the robot minesweeper.

There's long been concern about the ability of the new Littoral Combat Ship, whose missions include stopping mines, to accurately spot mines. Last year, the Pentagon's top weapons tester judged that the sensor and laser systems designed for the Littoral Combat Ship were "deficient" for their major mine-spotting task. And there's little margin for error: Mines are likely to blow the Littoral Combat Ship to bits if the UISS can't stop them.

But since the Littoral Combat Ship is designed to be modular – that is, to swap out its sensor packages when better ones come on-line – the Navy's response is to let the robots take care of hunting and sweeping mines. In April, it unveiled the Knifefish, an experimental, oblong underwater robot launched from a Littoral Combat Ship designed to hunt mines.

But the Knifefish can only find the mines. It can't destroy them. That's where the Navy wants the UISS to come in. In principle, a controller aboard a Littoral Combat Ship will program the UISS out to steam out to a set of coordinates, possibly provided by the Knifefish, and from there it'll emit its spoof signals prompting the mines to detonate, and then swim back on its own to its mothership, which can rest easier knowing it won't be steaming into a minefield. Ultimately, the Navy wants 52 of the robots, including training modules, so that every Littoral Combat Ship tasked with stopping mines carries a UISS.

The UISS and the Knifefish are part of a relatively new trend in naval robotics: unmanned ships and subs that can perform some of the Navy's most pressing and most dangerous missions. There's also the ACTUV, a project from the Pentagon futurists at Darpa, in which a semi-autonomous ship detects and hunts enemy submarines – another high-stakes mission that counters one of the Navy's most immediate threats. Previous Navy robotics projects have either taken to the skies, like with carrier-based drones or cargo helicopters, or focused on more peripheral jobs like putting out shipboard fires or even exploring space. There have been some sound technological reasons for this, like the tough propulsion and fueling challenges implicit in long-range robotic travel. But these newer programs point to increased Navy trust in robots to meet some of its most central maritime challenges.

The specifics of the UISS are still undecided. That'll be a job for Ashton and the Navy to work out with an industry excited for the robo-sweeper contract. (The AAI Corporation, for instance, hopes its Common Unmanned Surface Vessel will become the basis for the UISS.) The current plan is to get the UISS out into the fleet by 2017. If Ashton can pull that off, adversaries might have cause to flip the Navy's adage: Mine if you must.