Tag Archives: underwater drones

Stopping the Unstoppable: undersea nuclear torpedoes

Loads sonar buoys into a P-3 Orion, 2006 image from wikipedia

On July 20th 1960, a missile popped out of an apparently empty Atlantic ocean. Its solid-fuel rocket fired just as it cleared the surface and it tore off into the sky. Hours later, a second missile followed. An officer on the ballistic-missile submarine USS George Washington sent a message to President Dwight Eisenhower: “POLARIS—FROM OUT OF THE DEEP TO TARGET. PERFECT.” America had just completed its first successful missile launch of an intercontinental ballistic missile (ICBM) from beneath the ocean. Less than two months later, Russia conducted a similar test in the White Sea, north of Archangel.

Those tests began a new phase in the cold war. Having ICBMs on effectively invisible launchers meant that neither side could destroy the other’s nuclear arsenal in a single attack. So by keeping safe the capacity for retaliatory second strikes, the introduction of ballistic-missile submarines helped develop the concept of “mutually assured destruction” (MAD), thereby deterring any form of nuclear first strike. America, Britain, China, France and Russia all have nuclear-powered submarines on permanent or near permanent patrol, capable of launching nuclear missiles; India has one such submarine, too, and Israel is believed to have nuclear missiles on conventionally powered submarines.

As well as menacing the world at large, submarines pose a much more specific threat to other countries’ navies; most military subs are attack boats rather than missile platforms. This makes anti-submarine warfare (ASW) a high priority for anyone who wants to keep their surface ships on the surface. Because such warfare depends on interpreting lots of data from different sources—sonar arrays on ships, sonar buoys dropped from aircraft, passive listening systems on the sea-floor—technology which allows new types of sensor and new ways of communicating could greatly increase its possibilities. “There’s an unmanned-systems explosion,” says Jim Galambos of DARPA, the Pentagon’s future-technology arm. Up until now, he says, submariners could be fairly sure of their hiding place, operating “alone and unafraid”. That is changing.

Aircraft play a big role in today’s ASW, flying from ships or shore to drop “sonobuoys” in patterns calculated to have the best chance of spotting something. This is expensive. An aeroplane with 8-10 people in it throws buoys out and waits around to listen to them and process their data on board. “In future you can envision a pair of AUVs [autonomous underwater vehicles], one deploying and one loitering and listening,” says Fred Cotaras of Ultra Electronics, a sonobuoy maker. Cheaper deployment means more buoys.

But more data is not that helpful if you do not have ways of moving it around, or of knowing where exactly it comes from. That is why DARPA is working on a Positioning System for Deep Ocean Navigation (POSYDON) which aims to provide “omnipresent, robust positioning across ocean basins” just as GPS satellites do above water, says Lisa Zurk, who heads up the programme. The system will use a natural feature of the ocean known as the “deep sound channel”. The speed of sound in water depends on temperature, pressure and, to some extent, salinity. The deep sound channel is found at the depth where these factors provide the lowest speed of sound. Below it, higher pressure makes the sound faster; above it, warmer water has the same effect…

Even in heavily surveilled seas, spotting submarines will remain tricky. They are already quiet, and getting quieter; new “air-independent propulsion” systems mean that conventionally powered submarines can now turn off their diesel engines and run as quietly as nuclear ones, perhaps even more so, for extended periods of time. Greater autonomy, and thus fewer humans—or none at all—could make submarines quieter still.

A case in point is a Russian weapon called Status-6, also known as Kanyon, about which Vladimir Putin boasted in a speech on March 1st, 2018. America’s recent nuclear-posture review describes it as “a new intercontinental, nuclear-armed, nuclear-powered, undersea autonomous torpedo”. A Russian state television broadcast in 2015 appeared to show it as a long, thin AUV that can be launched from a modified submarine and travel thousands of kilometres to explode off the shore of a major city with a great deal more energy than the largest warheads on ICBMs, thus generating a radioactive tsunami. Such a system might be seen as preserving a second-strike capability even if the target had a missile-defence system capable of shooting ICBMs out of the sky…

One part of the ocean that has become particularly interesting in this regard is the Arctic. Tracking submarines under or near ice is difficult, because ice constantly shifts, crackles and groans loudly enough to mask the subtle sounds of a submarine. With ever less ice in the Arctic this is becoming less of a problem, meaning America should be better able to track Russian submarines through its Assured Arctic Awareness programme…

Greater numbers of better sensors, better networked, will not soon make submarines useless; but even without breakthroughs, they could erode the strategic norm that has guided nuclear thinking for over half a century—that of an unstoppable second strike.

Excerpts from Mutually assured detection, Economist, Mar. 10, 2018

The Sea Hunter Drone

darpa sea hunter. image from DARPA

The Anti-Submarine Warfare (ASW) Continuous Trail Unmanned Vessel (ACTUV) is developing an unmanned vessel optimized to robustly track quiet diesel electric submarines. … capable of missions spanning thousands of kilometers of range and months of endurance under a sparse remote supervisory control model. This includes…autonomous interactions with an intelligent adversary.
Excerpts from Anti-Submarine Warfare (ASW) Continuous Trail Unmanned Vessel (ASW Continuous Trail Unmanned Vessel (ACTUV))

See also SeaWeb live, DARPA Hydra

First Find then Erase Pollution

subcultron, image from https://ec.europa.eu/digital-agenda/en/news/bio-inspired-robots-will-examine-waters-venice

Subcultron is a swarm of at least 120 self-directing, underwater robots being developed by scientists in six countries to monitor Venice’s polluted waterways and transmit environmental data to government officials.The robots, shaped like fish, mussels, and lily pads to mimic the species’ hydrodynamics, carry sensors to monitor water conditions like temperature and chemical composition…The swarm communicates via the Internet-capable lily pads…
The robots use lithium ion batteries and solar cells for power. (Yes, enough sunlight gets through.)Some of the robots carry cameras. Others have electrodes that allow them to “see” by measuring objects crossing the electric fields they generate.Using wireless signals, human monitors can take over from the swarm’s AI software if something goes wrong. The European Commission has granted the project €4 million ($4.4 million).
Thomas Schmickl, the inventor, …..plans to build robot swarms that can monitor the oceans or even faraway moons that have water.

Excerpts from Innovation Subcultron, Bloomberg Business Week, Jan. 28, 2016

GPS System under the Sea: DARPA POSYDON

image from wikipedia

The objective of the POSYDON program is to develop an undersea system that provides omnipresent, robust positioning. DARPA envisions that the POSYDON program will distribute a small number of acoustic sources, analogous to GPS satellites, around an ocean basin.  By measuring the absolute range to multiple source signals, an undersea platform can obtain continuous, accurate positioning without surfacing for a GPS fix.

DARPA program  April 14, 2015

See also DARPA Hydra

The Engineered Seas: artificial reefs

Biorock. Image from wikipedia

Reefs improvised from junk often do not work well. Corals struggle to colonise some metals, and cars and domestic appliances mostly disintegrate in less than a decade. Some organisms do not take to paints, enamels, plastics or rubber. Precious little sea life has attached itself to the 2m or so tyres sunk in the early 1970s to create a reef off Fort Lauderdale, Florida. Tyres occasionally break free, smash into coral on natural reefs and wash ashore.

Yet building artificial reefs that are attractive to marine life can pay dividends. Some of the reefs built in Japanese waters support a biomass of fish that is 20 times greater than similarly sized natural reefs, says Shinya Otake, a marine biologist at Fukui Prefectural University. He expects further gains from a decision by the Japanese government to build new reefs in deep water where they will be bathed in nutrients carried in plankton-rich seawater welling up from below.

The potential bounty was confirmed in a recent study by Occidental College in Los Angeles. Over five to 15 years researchers surveyed marine life in the vicinity of 16 oil and gas rigs off the Californian coast. These were compared with seven natural rocky reefs. The researchers found that the weight of fish supported by each square metre of sea floor was 27 times higher for the rigs. Although much of this increase comes from the rigs providing fish with the equivalent of skyscraper-style living, it suggests that leaving some rigs in place when production ceases might benefit the environment.

Making reefs with hollow concrete modules has been especially successful. Called reef balls, these structures are pierced with holes and range in height up to 2.5 metres. The design is promoted by the Reef Ball Foundation, a non-profit organisation based in Athens, Georgia. Reef balls can be positioned to make the most of photosynthesis and for plankton to drift slowly across their curved inner surface. This improves the nourishment of plants and creatures setting up home within. A hole in the top reduces the chance of them being moved about by storm currents.

Concrete used to make a reef ball is mixed with microsilica, a silicon-dioxide powder, to strengthen the material and lower its acidity level to be more organism-friendly. The balls are cast from fibreglass moulds, which are typically sprayed with a sugary solution before the concrete is poured. This creates tiny hollows which provide a foothold for larval corals. Over 500,000 reef balls have been placed in the waters of more than 60 countries, and each one should last for some 500 years, says the foundation.

The value of artificial reefs has been boosted by the spread of GPS devices and sophisticated sonars on boats. This allows fishermen to locate the subsea structures precisely. It is necessary to be directly above the reef to reel in more fish, says David Walter of Walter Marine, an Alabama company that used to sink vehicles for fishermen but now places pyramid-shaped, hurricane-resistant steel, concrete and limestone structures to create artificial reefs. These constructions can cost nearly $2,000, but many fishermen consider them to be a good investment, especially to catch red snapper.

Using underwater drones for long-term studies of reefs and their associated marine life is also helping improve designs. Sensors can be installed on reefs to monitor boat traffic and activities such as fishing and scuba diving.

Perhaps the most innovative way to build a reef involves anchoring a frame made with steel reinforcing bars to the sea floor and zapping it continuously it with electricity. This causes minerals dissolved in seawater to crystallise on the metal, thickening the structure by several centimetres a year. Biorock, as the resulting material has been trademarked, becomes stronger than concrete but costs less to make. More than 400 “electrified” reefs, many the size of a small garage, have been built this way. Three-quarters of them are in the ocean around Indonesia.

Excerpts, Artificial reefs: Watery dwellings, Economist, Dec.6, 2014,  Technology Quarterly,  at 4

The SeaWeb Live: sound waves, drones and gliders

image from bluefinrobotics.com

UUVs [unmanned underwater vehicles]  will probably play a bigger role as roving wireless nodes that increase the reach of underwater networks. The latest “glider” UUVs consume very little battery power…. Already, gliders serving as “mules” are descending to sensors in deep water where they acoustically collect information. They then ascend to the surface and send the data via radio, says David Kelly, chief executive of Bluefin Robotics, which provides UUVs to half a dozen navies.

The US Navy has ordered several gliders to form underwater mobile networks. With no engine noise, a stealthy “swarm” of gliders could monitor submarines and ships entering a strait, for example, surfacing to transmit their findings. Floating gateway nodes, dropped from the air, allow messages to be sent to submerged devices via low-frequency acoustic signals. This scheme, known as Deep Siren and developed by Raytheon, an American defence contractor, has been tested by the British and American navies.

“Underwater networking will put an end to the ‘data starvation’ experienced by submarines”.  The combination of acoustic signalling and UUVs, which can deliver data physically, will put an end to the “data starvation” experienced by submarines, as America’s submarine command described it in a report last year. Often incommunicado, subs have been condemned to “lone wolf” roles, says Xavier Itard, head of submarine products at DCNS, a French shipbuilder. His firm is developing a funnel-shaped torpedo-tube opening that would make it easier for a UUV to dock with a submarine. Being able to send messages quickly via acoustic networks would enable submarines to take on more tactical roles—inserting special forces when needed to a nearby battlefield, say, or supporting ground operations by launching cruise missiles from the depths.

The Soviet-built ELF radio system remains a “backbone” of Russia’s submarine communications, according to a Norwegian expert. But in a clear vote of confidence in newer technologies, America shut down its own system in 2004. Thanks to steady progress in undersea networks, what was once a technological marvel was, a US Navy statement explained, “no longer necessary”. Whether via sound waves, laser pulses, optical fibres or undersea drones, there are now better ways to deliver data underwater.

Excerpt , Underwater networking: Captain Nemo goes online, Economist Technology Quarterly, Mar. 9, 2013, at 7

Gliders: the robot submarines

Ten years ago there were fewer than 30 gliders in the world, all built either by academic institutions or the armed forces. Now there are at least 400, and most are made by one of three firms: iRobot, whose product is called, simply, Seaglider; Teledyne Webb, which manufactures the Slocum Glider (named after Joshua Slocum, the first man to sail solo around the world); and Bluefin Robotics (the third member of the Massachusetts sea-glider cluster, based in Quincy), which sells the Spray Glider. Broadly speaking, these machines have three sorts of application: scientific, military and commercial.

At the moment, science rules the roost. For cash-strapped oceanographers, gliders are a blessing. Their running costs are negligible and, though buying one can cost as much as $150,000, that sum would purchase a mere three days of, say, a manned trip to the Southern Ocean.  Gliders, moreover, give a continuous view of what is going on, rather than the series of snapshots yielded by equipment lowered from a vessel at the surface. Besides tracking pollution, watching volcanoes and measuring icebergs, they are following fish around, monitoring changing temperatures in different layers of seawater and mapping the abundance of algae. The Ice Dragon, a modified Seaglider operated by the Virginia Institute of Marine Science, has explored under the Antarctic ice shelf, and another modified Seaglider, the Deepglider, can plumb the depths down to 6km (20,000 feet). Teledyne Webb’s Storm Glider, meanwhile, lurks in hurricane-prone areas, bobbing up to take readings during extreme weather.  Gliders are also quiet—so quiet that, as one researcher puts it, you can use them “to hear a fish fart”. This was demonstrated by a recent project run by the University of South Florida, in which a glider successfully mapped the locations of red grouper and toadfish populations on the West Florida Shelf from the noises the fish made.

Military applications are growing, too. America’s navy, for example, has ordered 150 gliders from Teledyne Webb’s sister company, Teledyne Brown, for what it calls its Littoral Battlespace Sensing-Glider programme. To start with, these gliders will be used individually, to measure underwater conditions that affect things like sonar. Eventually, the plan is to link them into a network that moves around in a co-ordinated manner.  Gliders are also ideal for gathering intelligence. Having no propellers and no engine noise, they are difficult to detect. They can be delivered by submarine, and can lurk unseen for as long as is necessary. Any shipping, whether on the surface or under it, which passes near a glider can be detected, identified and pinpointed without it realising it has been spotted. Indeed, the American navy is now evaluating a design called the Waveglider, made by Liquid Robotics of Sunnyvale, California, for submarine-detection work.

The third use, commerce, seems, at the moment, to be the smallest—though that may be because the companies involved are keeping quiet about what they are doing. But Joe Dyer, the chief strategy officer at iRobot, thinks oil-and-gas exploration will be a big market for the firm’s gliders, because they can survey large areas of seabed in detail at low cost.  ACSA, a French glider firm, has a similar market in mind. In March it launched the SeaExplorer, a streamlined, wingless glider with a speed of one knot—twice as fast as the American competition. According to Patrice Pla, ACSA’s marketing manager, SeaExplorer’s lack of wings reduces the chance of its getting tangled in nets. Its payload bay, meanwhile, is designed to take interchangeable modules so that it can hold whatever equipment is required. That means customers do not have to buy different gliders for different applications.

Nor is ACSA the only non-American in the field. A glider called Sea Wing, for example, has been developed at the Shenyang Institute of Automation, in China, by Yuan Dongliang of the country’s Institute of Oceanography. It was tested last year and operated successfully in the western Pacific at depths of up to 800 metres. Meanwhile, at Tianjin University, a team of glider researchers is trying to improve the machines’ endurance. They are testing fuel cells instead of batteries and are also working on the idea of powering them with a thermal engine that draws its energy from the differences in temperature between seawater at different depths.

Japanese researchers, too, are building gliders. At Osaka University, Masakazu Arima is involved in several glider projects. One is a small, low-cost version called ALEX that has independently movable wings. Another is a solar-powered device called SORA. Though SORA has to surface to recharge, its requirements are so modest that it does not take long to do so. It can travel underwater for months, surface for a few days, then carry on. It can therefore stay at sea indefinitely.

Dr Arima’s greatest interest, though, is like America’s navy’s: that his gliders should collaborate. His plan is to deploy 1,000 of them in a network that surveys and measures the oceans. If it works, the single spies of sea-gliding really will have become battalions, and the ocean’s fish will find themselves shadowed by shoals of mechanical counterparts.

Exploring the Oceans:20,000 colleagues under the sea, Economist, June 9, 2012, at 84

See also Underwater drones