DARPA takes its long-duration Manta undersea drone for a test-dip

DARPA's extended-duration unmanned undersea vehicle (UUV) is having its first aquatic excursion to test if this naval drone has wings, er, fins.

The splash test was part of DARPA's Manta Ray program for America's next-generation of undersea power projection, with PacMar Technologies and Northrop Grumman each building their own prototype UUVs. This test involved PacMar's big yellow scale prototype, the first of the pair to hit the drink. 

"This test provides important insights into key systems, allows us to validate assumptions and models, and gives us valuable data in preparation for our upcoming full-scale at-sea demonstrations," said Dr Kyle Woerner, Manta Ray program manager at DARPA.

"We are a critical step closer to realizing the program's objectives for a new class of long-endurance autonomous underwater vehicle."

"Splashing a vehicle is a major milestone for an undersea program," Woerner added. 

It's clear this is early days; it doesn't appear the craft did much more than basic tests in a harbor off Oahu, Hawaii. Per DARPA, the event included cycling of controls surfaces, activating the craft's thrusters and measuring its buoyancy. 

Meanwhile, Russia's president is claiming to have a nuclear-powered submarine drone ready for action.

Don't we already have Navy drones?

This isn't the US Department of Defense's first experiment with underwater drones. In 2015, the Virginia-class attack submarine USS North Dakota  test-launched an unmanned underwater drone in the Mediterranean. That craft, however, only has a life of 70 hours on battery power, giving it a limited useful lifespan.

The US Navy also deploys fleets of underwater drones for purposes of monitoring ocean currents, salinity and the like, one of which was nicked by the Chinese in 2016 before being returned a short time later. With their ocean-measuring tech, the devices aren't exactly built for war.

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Manta Ray, which DARPA kicked off in four years ago with a call for proposals, aims to be something else entirely: a craft able to "operate for extended durations without the need for human-present logistic support or maintenance," DARPA said. 

Designed to work in tandem with naval competent commanders, the craft are designed to be wholly independent once launched and offer "amplification of capacity without disrupting current operations." 

To do that, DARPA wants Manta Ray equipped with energy management techniques that allow it to harvest energy "at operationally relevant depths." When asked how DARPA intends to do that, Woerner told us there are several options. 

"Ocean wave energy that converts movement of the ocean into power, current energy (think river, ocean or tidal current), and ocean thermal, which takes advantage of the ocean’s gradient temperature," are all possibilities, Woerner said.

"Our partners at the Department of Energy have been looking at the ability to harness ocean energy for commercial grid purposes, and some of the advances we’ve made with Manta Ray may be transferable back to them," Woerner added.

DARPA also wants Manta Ray to include a low-power, high efficiency undersea propulsion system, "new low-power means" of underwater detection and classification of hazards, and the like. All this DARPA wants with the inclusion of "New approaches to mitigate biofouling, corrosion, and other material degradation for long duration missions," the Agency said. 

Northrop-Grumman doesn't intend to dip its UUV in the water until next year, DARPA said. Beyond that, Woerner tells us that DARPA expects to test the full-scale craft at sea in the next year and a half. ®