Realizing the Dreams of Da Vinci and Verne a Diverse Fleet of Innovative Deep-Submergence Vehicles Heralds a New Era of Ocean Exploration

http://oceanusmag.whoi.edu/v42n2/fornari.html

Realizing the Dreams of da Vinci and Verne A diverse fleet of innovative deep-submergence vehicles heralds a new era of ocean exploration

By Daniel Fornari, Director, transmits real-time images and data to sci- trenches to the mid-ocean ridge system— Deep Ocean Exploration Institute entists aboard ship. The ROV’s pilot uses the globe-encircling underwater volcanic and Senior Scientist Emerging Technology Emerging Geology and Geophysics Department the dexterous, force-feedback manipulator mountain chain where the ocean crust is Woods Hole Oceanographic Institution arms to collect samples, perform experi- born. (See “Unraveling the Tapestry of ments, and deploy, service, and download Ocean Crust,” page 40.) These discoveries eonardo da Vinci made the first sensors in the deep. led to the plate tectonics revolution in the Ldrawings of a submarine more than AUVs are unoccupied, untethered early 1970s, which created a fundamental 500 years ago, and Jules Verne published vehicles that are dispatched on pre-pro- new framework for understanding how 20,000 Leagues Under the Sea in 1875. grammed missions in the ocean. Like the Earth works. But only in the past few decades has the ROVs, they can operate submerged for Physical oceanographers pieced dizzying pace of technological advances longer periods than HOVs. But their free- together a general understanding of the allowed us to realize their dreams of swimming abilities, combined with more physics that control the ocean’s circulation exploring the ocean depths and taking precise control over their movements, and water masses. With climatologists, humans to the seafloor. also allow them to explore and map much they realized the importance of interac- For the past 40 years, submersible more of the seafloor and the water above tions between the oceans and atmosphere human-occupied vehicles (HOVs) such it per dive. in controlling Earth’s climate. as Alvin have given scientists direct access AUVs and ROVs, in concert with It was only in 1977 that biologists, to the seafloor and the ability to explore HOVs, will play indispensable roles in geologists, and geochemists found lush it from a firsthand and up-close perspec- establishing and servicing long-term sea- biological communities living off chemi- tive—one they could only fantasize about floor observatories. (See “Seeding the cals issuing from deep-sea hydrothermal from the decks of ships. But even more Seafloor with Observatories,” page 28.) vents on the crest of the volcanic mid- recently, humans have explored the abyss Together, the complementary capacities ocean ridge. This unexpected discovery with vehicles that even da Vinci and Verne of all three types of deep-submergence transformed conceptual thinking about never conceived: remotely operated vehi- vehicles provide synergies that have revo- how and where life could exist on this and cles (ROVs) and autonomous underwa- lutionized how scientists conduct research other planets and has stimulated new lines ter vehicles (AUVs). The latest generation in the ocean. of inquiry into the origins of life itself. of these innovative deep-submergence (See “Is Life Thriving Deep Beneath the vehicles has enhanced human access to Revolutionary discoveries Seafloor?” page 72, and “The Evolutionary extreme abyssal environments and has The era of modern oceanography was Puzzle of Seafloor Life,” page 78.) greatly expanded the capabilities of Earth launched by the HMS Challenger expe- and ocean scientists to investigate the far dition (1872-76), and until recently has The fourth dimension: time reaches and depths of the global ocean. relied on surface ships that go on expe- The discovery of hydrothermal vents ditions lasting from weeks to months to also catalyzed a realization that now domi- ROVs, AUVs, and HOVs collect data. Technical advances in instru- nates the thinking of marine scientists— ROVs are unoccupied underwater ments, especially after World War II, let the idea that myriad geological, chemical, vehicles controlled by a pilot aboard a scientists collect more and better data, biological, and physical processes in the support ship and tethered to a fiber-optic which fueled great leaps in knowledge deep ocean and on the seafloor are inter- cable. The cable offers unlimited power to about the Earth and ocean. connected. (See “Living Large in Micro- the vehicle, so ROVs can stay on the bot- Geophysicists mapped striking sea- scopic Nooks,” page 86.) tom longer than HOVs. The cable also floor features, ranging from deep To observe and understand interrelated

Woods Hole Oceanographic Institution 1 The National Deep Submergence Facility

Woods Hole Oceanographic Institution operates this “ﬂ eet” of deep-submergence research vehicles, which are used by scientists throughout the oceanographic com- munity. It is part of the University-National Oceanographic Laboratory System, an organization of 62 academic institutions and laboratories engaged in oceanographic research. The National Deep submergence Facility is funded by the Nation- al Science Foundation, the National Atmospheric and Oceanic Administration, and the Ofﬁ ce of Naval Research.

Alvin A 23-foot (7-meter)- long human-occupied vehicle (HOV) takes two scientists and a pilot as deep as 4,500 meters (14,764 feet).

Argo II A towed imaging and mapping vehicle, with video and still DSL-120A Depressor cameras and several diﬀ erent DSL-120A acoustic sensors. It can operate A towed 11-foot (3.3-meter)- around the clock to depths of long vehicle equipped with high 20,000 feet (6,000 meters). frequency (120 kilohertz) sonar to map the seaﬂ oor at about 2-meter Medea resolution. It operates to depths of 20,000 feet (6,000 meters). The depressor isolates DSL-120A from sea surface motion.

Jason 2 and Medea A remotely operated vehicle (ROV) controlled via a ﬁ ber-optic tether by a pilot aboard ship. It operates to depths of 6,500 meters (21,325 feet). Medea isolates Jason 2 from the ship’s surface motion. E. Paul Oberlander, WHOI Graphic Services Oberlander, E. Paul

2 Oceanus Magazine • Vol. 42, No.2 • 2004 processes that change over time, scien- studied because of their great size, remote regions. The portability of these vehicles tists need to collect a variety of data—over locations, or severe conditions (ranging also makes them useful to study ephem- spatial scales ranging from centimeters to from sea ice to stormy seas). eral or localized phenomena, such as phy- kilometers and time spans ranging from Though satellites provide global cov- toplankton blooms or upwelling events. seconds to days, years, and decades. They erage, they cannot For surveys, mapping, and data col- need to establish a continuous, compre- provide data much lection in shallow depths (330 hensive, long-term presence in the sea and beyond the sea feet, or 100 meters) on the seafloor—instead of trying to piece surface. AUVs are and coastal ocean together processes by taking intermittent probably the only regions, WHOI snapshots of a relatively few places and way that we will fill in REMUS scientist and engi- events. The difference in approach is like these large gaps in our (Remote Environmental Sensing UnitS neers led by Chris- seeking to understand family dynamics by knowledge and gain a full understanding topher von Alt built REMUS looking at a photo album versus spending of the short- and long-term oceanographic (Remote Environmental Sensing Units).

Emerging Technology Emerging a few weeks with a family. processes within nearly half of Earth’s This class of AUVs has already logged Here is where new ROVs and AUVs ocean basins. thousands of research missions. Specially will excel. Equipped with new suites of For this mission, autonomous gliders modified REMUS-based vehicles have been sensors, an expanding fleet of autonomous and drifters are being developed that can used to search for mines in Iraqi harbors and remote deep-submergence vehicles travel across open oceans over hundreds and for cracks in tunnels supplying water to will give scientists more time to explore, of miles and several weeks, taking mea- New York City from upstate reservoirs. with expanded capabilities to map, sample, surements all along the way. Drifters such and measure, over more territory—includ- as Argo, RAFOS, and Spray (now being A pioneer in the ocean frontier ing remote and inhospitable portions of developed by Brechner Owens at WHOI In the deep ocean, the Autonomous the oceans that have defied comprehensive and Russ Davis at Scripps Institution of Benthic Explorer (ABE) developed by exploration by surface vessels. Oceanography) are pre-programmed to WHOI researchers Dana Yoerger, Albert deflate and inflate a bladder, which causes Bradley, and Barrie Walden has been a Gliders, drifters, and REMUS them to sink as much as 2,000 meters pioneer. It has provided a testbed for inno- At the Woods Hole Oceanographic (6,500 feet) in the ocean and then rise vative robotics and electronics that have Institution (WHOI), the synergy and col- again to the surface as they are carried demonstrated the viability and value of laboration among engineers along by currents. Gliders are essentially deep-submergence AUV technology for a and scientists have consis- drifters with wings that provide lift and wide range of oceanographic research. It tently pushed the envelope on allow them to move horizontally. At can dive to depths of 5,000 meters (16,500 robotic oceanographic WHOI, Dave Fratantoni and col- feet) for 16 to 34 hours, equipped with technology. As a leagues are leading efforts to use an assortment of sensor packages (such result a diverse range and develop new glider systems. as high-resolution sonar, salinity, tem- of vehicles has evolved Equipped with diverse perature, and chemical recorders, current from drawing board to prototypes oceanographic sensors, meters, and magnetometers) to accom- and now into second generations of gliders and drifters can plish a variety of scientific missions, often vehicles working routinely on the ocean make fine-scale mea- during the same dive. Glider frontier. Individual types of vehicles are surements of tempera- AUVs add value to oceanographic adapted and equipped to accomplish spe- ture, salinity, current speed, expeditions by col- cific missions. phytoplankton abundances, lecting data In the coming decades, for example, and chemical changes, autono- oceanographers are eager to measure and then surface periodi- mously physical and chemical processes that drive cally to transmit the data while the world’s ocean circulation and influence via satellite to scientists on ships Earth’s climate. Many of these interactions shore. Fleets of these vehicles, simulta- occur between the atmosphere and ocean numbering in the hun- neously over vast regions, between and across dreds and eventually acquire oceans. To this day, many oceans—includ- thousands, will be able data using ing the South Atlantic, Arctic, Indian, and to make comprehen- ABE more traditional

Southern Oceans—have not been well- sive studies of vast oceanic (Autonomous Benthic Explorer) means. AUVs can also WHOI Graphic Services Oberlander, Illustrations E. Paul by

Woods Hole Oceanographic Institution 3 maximize the effectiveness of able to move in Andrew Bowen, Dana Yoerger, and col- other vehicles. During a any direc- leagues in the WHOI Deep Submergence 2002 expedition to tion or turn Laboratory (DSL), under the leadership of the Galápa- in place Robert Ballard. The lab designed and built gos Rift led by so it could an improved second-generation Jason WHOI biolo- maneuver ROV, which was launched in 2002 and gist Tim Shank close to the is now in service as part of the National and his NOAA bottom. It does this well, but Deep Submergence Facility at WHOI. colleague Steve at the cost of efficiency in trav- One disadvantage of ROVs, however, Hammond, ABE Sentry eling straight or up and down. It is is that they can’t cover as much ground as demonstrated that it ideal for close-to-the-bottom AUVs in the same amount of could survey the seafloor by night, surface surveying and photogra- time. The ROV tether, which at dawn, and deliver high-precision maps phy. The immense value can be thousands of meters long that scientists in Alvin used to guide their of these maps spurred and an inch thick, produces explorations that day. WHOI engineers to drag on the vehicle, and makes it ABE’s capability to adapt its naviga- design a second-genera- less maneuverable and vulnerable tion to maintain a precise course over tion vehicle called Sentry, to entanglement, especially in dif- rugged seafloor topography gives it the optimized for sonar surveys ficult terrains. To combine the ability to make high-precision seafloor in rugged terrain. Sentry strengths of both types of vehi- maps. In a typical dive, ABE’s sonars can will give up the ability to move SeaBED cles, Bowen and Yoerger of the image features less than a meter in length directly sideways or to hold position WHOI Deep Submergence Lab- and a few tens of centimeters tall on a and heading, but it will be much more oratory, in collaboration with Louis square kilometer of terrain. That is the efficient in forward travel, steep climbs Whitcomb of Johns Hopkins University, equivalent of being able to see footprints and dives, and vertical motion. have begun to design a Hybrid Remotely on a football field from the bleachers. WHOI scientists are also designing Operated Vehicle (HROV), which will The scale and resolution of these maps other AUVs with spe- be able to switch back and forth to alone are giving scientists the ability to cialized capabilities for operate as either an AUV correlate seafloor features and biologi- specific missions. One or an ROV on the same cal and geological processes in ways that example is SeaBED, cruise. It will use a light- were previously impossible. developed by WHOI weight fiber-optic cable, scientist Hanumant only 1/32 of an inch in Sentry, Puma, and SeaBED Singh and col- diameter, which will allow AUVs’ high-resolution mapping abili- leagues. It is an the HROV to operate and ties will also play a key role in the develop- AUV that can fly maneuver at unprecedented ment of long-term, deep-sea observatories slowly or hover over depths without the high-drag by identifying optimal locales to deploy the seafloor to depths Jaguar and expensive cables and winches typi- sensors measuring a wide range of chemi- of 6,000 feet (2,000 cally used with ROV systems. Once the cal, biological, and geological processes meters), making it particularly suited to HROV reaches the bottom, it will conduct over time. In the future, deep-sea obser- collect highly detailed sonar and opti- missions while pay- vatories will include docking stations for cal images of the seafloor. With Singh and ing out as much AUVs. These AUVs will be programmed other colleagues, WHOI scientist Rob as 20 kilome- to be dispatched from their docks to rap- Reves-Sohn is developing Puma and Jaguar, ters (about idly respond to fast-breaking or ephemeral two AUVs designed to search for and inves- 11 miles) events in the oceans that ships could never tigate hydrothermal vents under the ice- of micro- reach in time to observe—an earthquake, covered Arctic Ocean. (See “Unique Vehi- cable. for example, or a temperature or chemical cles for Unique Environments,” page 25.) Pilots change—and conduct timely sampling or on sur- deploy experiments. ROVs and HROVs face vessels As good as ABE is, WHOI engineers AUVs’ advantages are complemented will remotely HROV are striving to make it and its progeny bet- by ROVs, such as the pioneering Jason control the HROV (Hybrid Remotely ter. For instance, ABE was designed to be ROV, first developed in the late 1980s by via the microcable, Operated Vehicle)

4 Oceanus Magazine • Vol. 42, No.2 • 2004 ��

��

Emerging Technology Emerging �� E. Paul Oberlander, WHOI Graphic Services Oberlander, E. Paul

which will be jettisoned upon completion the direct, three-dimensional, full-con- 99 percent of the seafloor. (At its current of the mission. Untethered, the HROV textual vision of the human eye, com- depth limit of 4,500 meters or 14,765 feet, will guide itself to the surface for recov- bined with the ingenuity of the human Alvin can reach 63 percent of the seafloor.) ery by a ship, and the microcable is then mind on the scene. Together, all these new deep-submer- recovered for reuse. Forty years after Alvin was delivered gence vehicles will be at the vanguard of a The HROV will bring ROV capabili- in 1964, WHOI scientists have embarked new era of ocean exploration, leading us ties to places where it could not be used on designing a new replacement HOV, deeper into the ocean frontier and augur- before, such as the ice-covered Arctic. If funded by the National Science Founda- ing a new era of discovery. the ROV cable is severed during opera- tion, with many improvements, including —Oceanus Editor Laurence Lippsett tions, the AUV capabilities will automati- an increased diving depth of 6,500 meters contributed to this article. cally take over to continue the mission (21,325 feet) that will allow it to reach autonomously or to return the vehicle to the surface. The HROV will also be Dan Fornari (left) became Director of the Deep Ocean Exploration Institute at capable of diving to 11,000 meters (36,000 WHOI in 2004. He is internationally recognized for his research on volcanic and feet)—deep enough to explore the deepest hydrothermal processes and mapping at mid-ocean ridges, and on the structure and magmatic processes at oceanic transforms and oceanic islands, such as Ha- parts of the world’s oceans in the trenches waii and the Galápagos. Over 35 years, he has participated in 55 research cruises of the western Pacific. in the Pacific, Atlantic, and Indian Oceans, and has completed more than 100 dives in Alvin and other Navy submersibles. In 1993, he became the first Chief A new replacement for Alvin Scientist for Deep Submergence at WHOI, and helped usher in a new era in deep-submergence technology using Alvin with the ROV Jason 2 and high-resolu- The remote capabilities of AUVs and tion sidescan sonar systems. Fornari has served on numerous scientific panels, and national and interna- ROVs have proved enormously valuable, tional committees, including the President’s Commission on Ocean Exploration in 2003. Together, he and but there is still no substitute for being Susan Humphris developed Dive and Discover, an education and outreach Web site (www.divediscover. whoi.edu) that brings the excitement of oceanographic science to thousands of students each day. He is there. In particular, two-dimensional ably assisted most days by his personal assistant, Riley. images from ROVs still cannot provide

Woods Hole Oceanographic Institution 5