XPost: sci.military.naval, soc.history.war.misc

I say "Huh",
'creates electrical energy by harnessing the power of the ocean’s
“thermal gradient,”'

from https://nationalinterest.org/blog/buzz/northrop-grummans-manta-ray-could-change-undersea-warfare-forever-210708

April 23, 2024 Topic: Security Region: Europe Blog Brand: The Buzz
Tags: Anti-Submarine WarfareUndersea WarfareManta RayNorthrop GrummanMilitaryRussia

Northrop Grumman's Manta Ray Could Change Undersea Warfare Forever
Northrop Grumman describes the new Manta Ray drone as: “A new class of
UUV, it is an extra-large glider that will operate long-duration,
long-range and payload-capable undersea missions without need for
on-site human logistics.”

by Alex Hollings
Summary: The Manta Ray, a new uncrewed underwater vehicle (UUV)
developed by Northrop Grumman under DARPA's guidance, represents a
significant innovation in deep-sea technology. Designed for prolonged autonomous operations without human logistic support, Manta Ray aims to
perform complex undersea missions, including scientific research and
military tasks.

-Featuring energy-harvesting capabilities and a unique design inspired
by its namesake, the Manta Ray can operate at depths unreachable by
traditional submersibles, marking a major step towards autonomous
deep-sea exploration and surveillance.

-This UUV is poised to enhance maritime security, particularly in anti-submarine warfare, by leveraging advanced propulsion and stealth technologies.

Revolution Under the Sea: Northrop Grumman Unveils the Manta Ray Deep
Sea Drone
On February 3, 2024 – just shy of two years after Russian forces invaded Ukraine, the Russian Navy rolled out its fifth modernized Borei-A Class
nuclear ballistic missile submarine from the Sevmash shipyard in
Severodvinsk, Northern Russia. This new class of undersea predator is
alleged to be significantly stealthier than previous Russian submarine
designs thanks to its use of pump-jet propulsion – a first for Russia. Russian media has claimed this new submarine is five times quieter than Russia’s latest nuclear-powered Akula-class submarines, and two times
quieter than America’s Virginia-class attack submarines.

With at least two more Borei-A Class vessels already in production, it’s clear that, despite Russia’s military woes in Ukraine, the country
remains heavily invested in maintaining and extending its potent nuclear
strike capabilities, on which Russian President Vladimir Putin seems to increasingly rely to stave off direct Western interference with his
military objectives.

But Russia’s undersea fleet may soon be facing a new kind of threat… one that lurks deeper than any of their submarines can sail, hibernating
with nearly no detectable electromagnetic emissions, and capable of
rapidly coming to life and soaring through the sea like an exotic
predator combined with a stealth bomber, taking on submersible threats
with a variety of potential payloads, before once again anchoring itself
to the seabed to lay in wait once more.

On April 8, Northrop Grumman officially unveiled its new prototype deep
sea drone, the Manta Ray uncrewed underwater vehicle (UUV). This new
undersea drone is designed to conduct extended-duration autonomous
operations at long ranges with minimal need for human support, according
to the firm, making it uniquely suited for a wide variety of undersea scientific and potential combat operations.

Borei-Class Submarine

Northrop Grumman describes the new Manta Ray drone as: “A new class of
UUV, it is an extra-large glider that will operate long-duration,
long-range and payload-capable undersea missions without need for
on-site human logistics.”

While details about Manta Ray and its full range of intended
capabilities remain sparse, we can glean some information about the
goals informing this endeavor through the contracting documents and announcements released by the Defense Advanced Research Projects Agency,
or DARPA, leading up to this point.

THE UNDERSEA PATH TO MANTA RAY
In March 2020, DARPA awarded developmental contracts to Lockheed Martin, Northrop Grumman, and Navatek to mature concepts for what DARPA Manta
Ray Program Manager Dr. Kyle Woerner describes as “an autonomous
underwater vehicle that’s out operating on its own, harvesting energy,
and completing whatever mission it’s given.” By December 2021, the field narrowed to Northrop Grumman and Navatek (now known as Pacmar
Technologies) with Phase 2 contracts awarded to each for the
construction of full-scale technology demonstrators.

In September 2023, Pacmar Technologies’ Manta Ray sub-scale prototype
began “splash testing,” meant to verify the forthcoming platform’s
sensor suite and key autonomy behaviors for the full-scale platform. And
now, Northrop Grumman has unveiled its own full-scale technology
demonstrator, which, according to the company, is modular to support
easy shipping for expeditionary deployments, and has the ability to
anchor to the sea floor and hibernate for extended periods to reserve power.

Northrop Grumman’s Manta Ray design resembles its namesake fish,
adopting a similar “sea-glider” shape.

Based on the Manta Ray program description, also penned by Dr. Woerner,
the driving factor in this effort was to field a deep-sea drone that
could specifically operate for long durations without the need for
logistical support. While not specified in this language, the endeavor
seems to prioritize both long-duration deep-sea operations and the force-multiplying effect of passing these roles off to a drone with
minimal support requirements.

“If successful, this new class of UUV will give the combatant commander
an amplification of capacity without disrupting current operations by
remaining independent of manned vessels and ports once deployed,” Dr.
Woerner wrote.

EXTENDED-DURATION OPERATIONS AT EXTREME DEPTHS
To minimize the logistical requirements of the drone, DARPA’s
documentation calls for novel energy management and even
energy-harvesting techniques for use in dea sea environments – or
creative new ways to minimize energy draw and even to supplement energy
stores using its environment – as well as a wide variety of new onboard systems designed to minimize power requirements, from propulsion to
threat detection and beyond. A fourth company, Metron Inc, has also been contracted to mature technologies in that specific vein.

Another evident element of the Manta Ray program is to operate at
extreme depths that would otherwise be impossible, or economically
infeasible, for Navy or civilian submersibles.

“A main driver for wanting to go toward underwater vehicles in their
ability to go to depths that humans and many human systems are not able
to go to,” Dr. Woerner explained on the Voices from DARPA podcast in
October 2022.

Woerner went on to explain that DARPA chose the name Manta Ray as it
emphasized the program’s aim of fielding a disruptive submersible
technology that departs from the sleek torpedo-like design that’s so
common in military submarines, and instead leans into the efficient
shapes of undersea life – like the large and exotic-looking Manta Ray
fish. While Woerner clarified that DARPA was happy to accept designs
that didn’t resemble the Manta Ray found in nature, Northrop Grumman
seemed to take the idea to heart when designing its submersible.

MANTA RAY WILL HARVEST ELECTRICAL ENERGY FROM ITS ENVIRONMENT
To understand the value Manta Ray can provide, it’s first important to recognize the limitations inherent to current-state deep-submersible technology. Most of today’s uncrewed underwater vehicles (UUVs) are
tethered directly to surface vessels for power and support, and the few
that aren’t still need to keep support (usually in the form of a crewed
ship on the surface) nearby because the systems can usually only operate
for periods of hours, or in a few extreme cases, days.

“So you can either chase them around with a host vessel, which is
expensive and takes a lot of time and requires humans above them – and
you have to offer them care and feeding and everything else that comes
with that – or you can find a way to extend endurance under the sea,”
Dr. Woerner explained. “So, part of this project from a military utility perspective is reducing the burden, if you will, on these human-operated ships.”

The single most limiting factor for UUVs today is power storage. A large submersible requires a great deal of power for propulsion alone, before
you even consider onboard control systems, sensor suites, and any
potential payloads. A significant area of focus for Manta Ray, beyond
designing systems with very low power requirements, is finding ways to
draw power from the submersible’s operating environment.

“One of the things that’s really interesting about ocean resources is
that they are persistent,” explains Kelley Ruehl, a research and
development mechanical engineer with Sandia National Laboratories who specializes in wave-energy conversion, or deriving electrical energy
from the power of ocean and river currents. But Ruehl, who is serving as
an advisor on the Manta Ray effort, says there are several other
potential avenues for power production under the sea beyond capturing
the power of currents, like salinity gradient power, which can be
derived in a variety of ways like Reversed Electro Dialysis (RED).

RED uses a stack of alternating cathode and anode exchanging
perm-selective membranes, with the compartments between membranes filled alternately with fresh water and seawater. The differences in salinity
in the water generate a voltage over the membranes that can be captured
and converted into electrical power.

Another potential solution Northrop Grumman has explored, in partnership
with renewable energy company Seatrec, is the Mission Unlimited Unmanned Underwater Vehicle (UUV) Station, which requires the deployment of a
separate “Thermal Energy Pod” that creates electrical energy by
harnessing the power of the ocean’s “thermal gradient,” or the mixing of warm and cooler currents. In effect, UUVs like Manta Ray can use the
Thermal Energy Pod like a gas station, returning to fill up any time
their onboard stores are running low.

OVERCOMING THE COMMUNICATION PROBLEM
The insulated connectors between the Manta Ray and the Thermal Energy
Pod can also accommodate the transfer of data to command elements on
shore. That uploaded data is then transferred into small devices
Northrop calls “data bubbles” that can be deployed from the Energy Pod
to relay vital information back to command elements elsewhere in the world.

“When released from the station, they float to the surface and begin
using their RF satellite communications antenna to transmit data to
shore, to a satellite, or to a ship.” explained Brian Theobald, chief engineer for Northrop’s Manta Ray program.


Next
Akula-Class Submarine from Russia
Russia's New Husky-Class Submarine Just Might Be Doomed
April 19, 2024

by Maya Carlin

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XPost: sci.military.naval, soc.history.war.misc

On 4/24/24 08:16, a425couple wrote:

I say "Huh",
'creates electrical energy by harnessing the power of the ocean’s “thermal gradient,”'

from https://nationalinterest.org/blog/buzz/northrop-grummans-manta-ray-could-change-undersea-warfare-forever-210708

April 23, 2024  Topic: Security  Region: Europe  Blog Brand: The Buzz Tags: Anti-Submarine WarfareUndersea WarfareManta RayNorthrop GrummanMilitaryRussia

Northrop Grumman's Manta Ray Could Change Undersea Warfare Forever
Northrop Grumman describes the new Manta Ray drone as: “A new class of
UUV, it is an extra-large glider that will operate long-duration,
long-range and payload-capable undersea missions without need for
on-site human logistics.”

by Alex Hollings

This is page 2,
Northrop Grumman's Manta Ray Could Change Undersea Warfare Forever
Northrop Grumman describes the new Manta Ray drone as: “A new class of
UUV, it is an extra-large glider that will operate long-duration,
long-range and payload-capable undersea missions without need for
on-site human logistics.”

by Alex Hollings
This could help to address one of the biggest challenges facing any
deep-sea platform whether crewed or uncrewed – communications.

Military platforms that operate on or above the surface rely heavily on
radio communications, but radio waves cannot penetrate the oceans’
highly conductive salt water. As a result, America’s nuclear ballistic missile submarines rely on Very Low Frequency (or VLF) transmissions
relayed via massive sprawling antenna complexes positioned in five installations around the world. If those stations are taken out by enemy attack, a fleet of specially-equipped TACAMO (Take Charge and Move Out) aircraft will deploy five-mile-long antennas then fly in tightly
overlapping circles above the ocean to transmit what effectively amounts
to a text message to submarines deep beneath the waves.

Manta Ray may be equipped for VLF communications as well, but due to the inherent limitations associated with these sorts of transmissions, the
“data bubbles” released from Thermal Energy Pods could provide a simple means of standard communications at regular intervals.

This also means that an uncrewed submarine meant for extended-duration
missions needs to be able to operate largely autonomously, with very
little direct interaction with the world above. As such, Manta Ray will
need to adopt, or adapt, some means of autonomous control, potentially
through the use of AI.

Power production is far from the only challenge Manta Ray needs to
overcome in order to have a palpable strategic impact on maritime
defense. Novel solutions for corrosion control, undersea obstacle
avoidance, and the extreme degree of reliability required for extended operations in such unforgiving environments also need to be developed.

MANTA RAY COULD PROVIDE A BIG BOOST TO ANTI-SUBMARINE WARFARE
While there are several potential military and scientific applications
for Manta Ray, one strategically valuable place to start might be in
countering adversary submersibles – specifically, those armed with
nuclear weapons.

Despite Russia’s poor performance throughout the ongoing invasion of
Ukraine, Russia’s undersea capabilities remain among the best in the
world, and as such, represent a potent threat to American security.
Currently, Russia operates two classes of nuclear-armed ballistic
missile submarines, including five Delta IV submarines and eight
Borei-Class vessels of different iterations. Despite Russia’s
sanction-based economic woes, production continues on three additional modernized Borei-A-class vessels. Russia’s Status-6 Oceanic Multipurpose System, also known as Poseidon or Kanyon, is a high-speed nuclear
torpedo designed to travel distances as great as 5,400 nautical miles
(6,200 miles) at speeds as high as a claimed 54 knots (a shocking 62
miles per hour), before lying in wait inside enemy harbors, waiting for
the command to detonate its nuclear payload.

Initial Russian claims suggested that Status 6 could carry a massive
50-megaton nuclear payload, though that has since been revised to a more realistic two megatons. Nonetheless, a two-megaton blast would still be
roughly 100 times larger than the atomic bomb dropped on Hiroshima.
There remains some debate about whether or not such a detonation could
create an irradiated tidal wave, with recent analyses largely
disregarding the potential for this threat. Yet, such a detonation
inside an American harbor would, nonetheless, be catastrophic.

This threat is more potent than many realize. In 2017, a Russian
military documentary series alleged that a fleet of Russian
Shchuka-B-class submarines armed with long-range cruise missiles was
dispatched with orders to take up positions just outside American ports
with U.S. Navy installations. The Russian Navy claimed to have completed
the mission successfully, saying that they managed to operate just
outside American territorial waters (extended 12 nautical miles to sea)
without being detected.

The United States did not publicly respond to Russia’s claims — and
likely for good reason. Had the Pentagon dismissed the Russian claims as
false, Russian information operations would have spun that as tacit confirmation that America was unable to detect their presence. If the
U.S. Navy did indeed detect and track the presence of these Russian
submarines, revealing that could inadvertently provide some indication
as to just what sorts of detection capabilities the United States does
have, which may prompt renewed investment from the Russian Navy to find
ways to circumvent it.

But regardless of the claim’s truth, the U.S. Navy took the threat
seriously. Shortly after Russian officials made this claim, Secretary of
the Navy Richard V. Spencer announced the United States was
re-establishing its North Atlantic-based 2nd Fleet specifically to
counter emerging Russian threats.

This decision echoed sentiments published two years prior by then-Naval
Forces Europe commander Adm. James Foggo III.

“Russian submarines are prowling the Atlantic, testing our defenses, confronting our command of the seas, and preparing the complex
underwater battlespace to give them an edge in any future conflict,”
Foggo wrote in U.S. Naval Institute’s Proceedings. “Not only have Russia’s actions and capabilities increased in alarming and
confrontational ways, its national-security policy is aimed at
challenging the United States and its NATO allies and partners.”

Since then, the U.S. has also renewed investments into new forms of
submarine detection, with new efforts like the Persistent Aquatic Living Sensors (PALS) program starting in 2019, which aims to use track natural
and “modified” aquatic sealife near shore to use their behavior to
identify the presence of encroaching submarines. Other efforts, like the Anti-Submarine Warfare (ASW) Continuous Trail Unmanned Vessel (ACTUV),
which aims to field semi-autonomous submarine-hunting surface ships,
that were already underway have also seen renewed interest and investment.

Northrop Grumman’s new Manta Ray system could be an incredibly potent
new addition to America’s growing anti-submarine arsenal, providing a sustained weaponized presence that’s all but impossible to detect while inactive. Once submarine activity is identified via any one of the
various sensing methods, automated responses in the form of both surface
and subsurface platforms would take action immediately, making it harder
than ever to sneak a submarine (or nuclear torpedo) in American or
allied harbors.

To that end, DARPA is not placing all its eggs into Northrop Grumman’s basket: according to recent statements from DARPA, they will continue to
mature other Manta Ray platforms in development.

“Manta Ray performers have each taken unique approaches to solving the
wide range of challenges related to UUV endurance,” program manager
Commander Kyle Woerner, said in the statement. “To me, this is a clear
sign we are tackling a complex problem without a clear ‘one size fits
all’ solution.”'

About the Author: Alex Hollings
Alex Hollings is the editor of the Sandboxx blog and a former U.S.
Marine that writes about defense policy and technology. He lives with
his wife and daughter in Georgia.

This article was first published by Sandboxx News.

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On 4/24/24 09:47, Jim Wilkins wrote:

"a425couple"  wrote in message news:xn9WN.37030$moa7.11210@fx18.iad...

I say "Huh",
'creates electrical energy by harnessing the power of the ocean’s “thermal gradient,”'

------------------------------------

There are several possible electrical energy sources, the sodium ion
battery the article mentioned, thermopiles that create electricity from internal vs external temperature differences, and compression from
varying depth pressure, though that may conflict with the powered
expansion and contraction that lets it travel with minimal power
consumption by gliding up and down on buoyancy differences. https://en.wikipedia.org/wiki/Underwater_glider

https://www.americanpiezo.com/piezo-theory/generators.html
BBQ igniters are a common example.

https://en.wikipedia.org/wiki/Thermopile
The common example keeps a gas heater solenoid valve open using energy
from the pilot light, and lets the valve close to prevent an explosion
if the pilot goes out. They are how spacecraft exploring outer planets generate electricity from the heat of radioactive decay.

The drone might recharge itself on the surface with solar panels.

CMOS electronics use essentially zero power except when switching, so
they can remain powered but idle for long periods without draining a
battery, and use very little power if clocked at low speed, like a wrist watch with a 32,768 Hz crystal oscillator.

Interesting. Thanks.

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