The Navy's Future Fleet May Include Submarines
Without Sailors
20 Apr 2019
The Los Angeles Times | By Samantha Masunaga
The U.S. naval fleet of the future may one day
include submarines without a sailor from bow to stern that prowl the depths of
the ocean, navigating mine-infested waters to gather intelligence or even
clandestinely drop explosives.
The military views autonomous vehicles as a way
to accomplish missions deemed too risky, mundane or expensive for human crews.
While aerial drones have largely been tasked with these types of duties for
more than a decade, the Navy is now increasingly funding robotic ships and undersea
drones to complement the work done by its crewed vessels.
Last month, Boeing Co. beat out rival Lockheed
Martin Corp. for a $46.7-million Navy contract modification to build an Orca
undersea drone. Boeing had previously won a contract to build four of the Orca
drones, bringing the total contract value for the five to $274.4 million. A
large chunk of work will be done at the aerospace giant's Huntington Beach
facility, and the drones are expected to be completed by 2022.
Neither Boeing nor the Navy have disclosed the
size of the robot submarines, but Boeing has previously developed and tested a
51-foot-long underwater drone prototype called the Echo Voyager.
Analysts say the contract, along with the
Navy's new fiscal year 2020 funding request for further development of uncrewed
surface vessels and undersea drones, indicates a new level of commitment to
autonomous sea operations.
"What it shows is that the Navy is willing
to start putting some real money behind the acquisition of unmanned undersea
vehicles," said Bryan Clark, senior fellow at the Center for Strategic and
Budgetary Assessments think tank in Washington, D.C. "This is the first
time the Navy has put significant money down on UUV [unmanned underwater
vehicles] that have a military, war-fighting capability."
Analysts say undersea drones could be used for
missions once conducted by crewed submarines, while the lack of a crew gives
the drones an advantage in conducting "persistent surveillance for
activities that might take place in an area where there is concern about
underwater mines," said Margaret E. Kosal, associate professor in the Sam
Nunn School of International Affairs at the Georgia Institute of Technology.
Future missions might also include deploying
military payloads or weapons into a contested area, Clark said. But developing
undersea drones comes with a host of technical challenges not experienced by
aerial counterparts.
For one, water is a much thicker medium, which
makes real-time communication much more difficult than sending transmissions
through air, said Rosa Zheng, a professor in the department of electrical and
computer engineering at Lehigh University.
Undersea drones can use a few different methods
of communication, such as acoustics, but must be willing to trade off a slower data
rate, shorter transmission distance, or both, she said.
As a result, the drones must be endowed with a
greater level of autonomy than aerial drones, said Scott Savitz, a senior
engineer at the Rand Corp. think tank. Unlike an aerial drone, which can access
satellite communications to gain its bearings and show what it sees in real
time to a human operator thousands of miles away, an underwater drone loses
access to the electromagnetic spectrum once it is below the waterline, he said.
That means the drone would have to handle
changing weather conditions or avoid obstacles underwater without human
assistance. It would also need to resurface to send faster transmissions and
gain access to GPS.
"There's a need to develop greater
autonomy for UUVs than there was for UAVs [unmanned aerial vehicles] and ... to
have enough trust in the system, which can only be achieved through testing,
evaluation, usage and so on," Savitz said.
Boeing has worked on some of these issues with
its Echo Voyager underwater drone prototype.
The 51-foot-long, yellow-and-gray
submarine-shaped drone has completed more than 2,500 hours of ocean testing,
including two sea trials. During the first tests in 2017, Echo Voyager operated
for about three months off the coast of Southern California while monitored by
a crewed chase boat.
The drone is powered by a hybrid
electric-battery/marine-diesel system. A generator kicks in when the battery
runs low, and the drone will periodically resurface to snorkel depth to raise a
mast that provides air to run the diesel engines, which recharge the batteries.
During the first sea trials, Boeing tested the drone's ability to surface,
recharge and submerge, as well as its control in currents and waves.
The drone is designed to be programmable so it
can launch from shore, complete its mission and then return when it's done,
said Deborah VanNierop, a Boeing spokeswoman.
Echo Voyager is currently in its second round
of sea trials, which began last year, VanNierop said. Testing and lessons
learned from Echo Voyager have been incorporated into the Orca design to
improve reliability and reduce risk, Boeing said. However, Van Nierop said the
two vehicles will not be exactly the same.
Eventually, the Navy could pair these
underwater drones with their uncrewed surface counterparts.
This year, the Navy's 132-foot-long Sea Hunter
autonomous surface vessel sailed from San Diego to Hawaii and back without crew
aboard. The ship's maker, Reston, Va.-based Leidos, said humans made "very
short duration boardings" only to check electrical and propulsion systems.
These kinds of medium-size vessels could be
used for sensing operations, to conduct electronic warfare and to support
crewed aircraft carriers, Clark said. Larger autonomous surface vessels could
even be used to deploy undersea drones.
"Just as it took some time to figure out
how submarines would be interacting with the rest of the fleet, and their
various roles ... likewise, there's going to be an evolutionary process with
respect to deployment of UUVs for a wide range of missions," Savitz said.
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