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Mission Possible Adapted by Margaret Olsen and Brandy Wilbur from the �OAA Ocean Explorer Activity

I, Robot, Can Do That!

Grade Level: 7th

-12th

�ational Science Standards: � Content Standard A: Science as inquiry: Abilities necessary to do scientific inquiry;

Understandings about scientific inquiry. � Content Standard E: Science and Technology: Abilities of technological design;

Understandings about science and technology. � Content Standard F: Science in Personal and Social Perspectives; Science and

technology in society. � Standard G: History and Nature of Science; Nature of Science

Purpose/Focus Question: How can underwater robots be used to assist scientific explorations. Objectives: After completing the activity the students will be able to:

• describe and contrast at least three types of underwater robots used for scientific explorations.

• discuss the advantages and disadvantages of using underwater robots in scientific explorations.

• identify robotic vehicles best suited to carry out a specific task. Background Information: See background information sheets.

Materials:

Mission Possible robot cards, laminate if possible Mission Description Cards (enlarge these as large as you can) Underwater Robot Capability Survey (one for each mission) Post It Notes to use as bid sheets Large sheet of paper or white board with all mission letters listed on it.

Procedure:

1. During this activity, your assignment is to investigate underwater robots that can

be used to perform various tasks that support scientific exploration of the deep ocean.

2. You will work in groups and each group will be assigned one of the following robots: ABE, Hercules, ROPOS, General Purpose ROVs, RCV-150, or Tiburon.

3. Fill out the “Underwater Robot Capability Survey Form” for your Robot. 4. Around the room, you will find 10 Mission Description Cards. Read each card

and decide if your Robot can handle that mission. 5. If your robot has the capabilities to handle the mission, you will bid on the

mission by placing the name of your Robot on a post it note and then placing the

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post it note (your bid card) beside the mission letter on the large sheet with all the missions listed on it.

6. After all missions have been bid on, your group will be asked to explain why you think your Robot is the best to handle the missions that your group bid on.

�ote to teacher: This is done as a “whole” class activity, but you may want the students to do their own internet research on the vehicles and then give them the ‘Mission Description Card” and have them to fill out an Underwater Robot Capability Survey Form for each mission. Conclusions: In your own words, write a short paragraph explaining how underwater robots can be used in scientific research. Source: Adapted for use in the 2007 COSEE SE Ocean Sciences Leadership Institute by Margaret Olsen, from a NOAA Ocean Explorer Activity – “I Robot Can Do That”. The original activity can be found at: http://www.oceanexplorer.noaa.gov/explorations/05lostcity/background/edu/edu.html

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Underwater Robot Capability Survey

�ame of Robotic Vehicle: _________________________________________________

Maximum Operating Depth: ______________________________________________

Tethered or Autonomous: ________________________________________________

Minimum �umber of Crew Required for Operation:

Tools:

Special Capabilities or Advantages:

Other Details:

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Mission Descriptions

A.

We are planning an

expedition to study an

unexplored area of the

Atlantic Ocean near Blake

Ridge with a maximum

depth of 3,000 meters. We

are particularly interested

in geological formations,

and want to collect rock

cores and samples of

biological organisms that

may be living on these

formations.

B.

As part of the ongoing

study of the Lost City, we

want to survey other parts

of the Atlantis Massif for

similar vent communities.

This will require a robot

that can travel back and

forth across the mountain,

maintaining a distance of

about 5 meters from the

bottom, with continuous

depth recordings and video

images taken every 10

meters.

C.

We are studying fish

communities around deep

water coral reefs off the

coast of Florida (depth 500

– 700 meters). We need

video records of fish species

in a variety of habitats,

particularly under coral

ledges near the bottom

D.

We are developing an

educational program for our

city aquarium, and want to

show some of the capabilities

of underwater robots. What

kind of robot would be most

practical for this purpose?

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Mission Descriptions

E.

Our expedition is studying the

linkages between pelagic (mid-

water) and benthic (bottom)

communities associated with a

hydrothermal vent in the Gulf

of Mexico (depth is

approximately 2,500 meters).

We want to collect biological

samples from both areas, as

well as geological samples

(including rock cores) from

the benthic areas.

F.

We are exploring the wreck of

a Spanish galleon that lies in a

deep canyon 3,000 meters

below the surface. We need a

complete, detailed

photographic survey of the

area around the ship, and also

want to be able to recover

artifacts that may be

discovered.

G.

A Pisces submarine has

become tangled in the rigging

of a sunken freighter in 1,500

feet of water. We need a robot

to survey the situation and cut

the rigging to free the

submarine.

H.

We are exploring a series of

underwater caves,

approximately 300 meters

deep. The entrances to some

of these caves is only about

300 cm square. We need video

images of the interior of these

caves to plan further

explorations.

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Mission Descriptions

I.

Our research team is studying

an unexplored chain of

underwater volcanoes. We

want to sample geological

formations as well as

biological communities, but

won’t know exactly what types

of samples will be needed until

we can see the area. Depths in

our study area will be between

1,500 and 4,500 meters.

J.

Our scientific team needs to

monitor the water

temperature around a newly

erupting volcano, two miles

below the surface of the ocean.

We need samples taken every

hour for a month.

K.

We are studying the

organisms associated with a

deepwater habitat (1,000 –

2,000 meters depth) and want

a complete photographic

record of the study area

(approximately 10,000 square

meters. We also need to

collect samples of unknown

organisms for identification.

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Autonomous Benthic Explorer (ABE)

• Capable of operating to depths up to 5,000 meters

• Autonomous vehicle; no tether to support ship

• Tools: video cameras, conductivity and temperature sensors, depth recorder, magnetometer, sonar, wax core sampler, navigation system

• Developed to monitor underwater areas over a long period of time

• Follows instructions programmed prior to launch; data are not available until robot is recovered

• Operates independently during missions, but requires technicians and engineers for maintenance, as well as data managers to retrieve information stored in computer memory.

The Autonomous Benthic Explorer, more commonly known as ABE is the first underwater robotic vehicle of its kind. ABE was designed and built at the Woods Hole Oceanographic Institution (WHOI) in the mid 1990’s. ABE weights approximately 1200 pounds and is a little over 2 meters long. ABE's top cruising speed is 2 knots.

As an Autonomous Underwater Vehicle (AUV), ABE is a true robot, able to move on its own without a pilot or tether to either ship or submersible. This gives ABE the advantage of covering large areas of underwater terrain. ABE was invented to address scientists' frequent need to monitor underwater areas over long periods of time, a job that can be very expensive using surface ships and manned submersibles for repeated visits. ABE is designed to perform a predetermined set of maneuvers, take photographs, and collect data and samples within an area about the size of a city block. After accomplishing its mission, ABE “goes to sleep,” conserving its power supply for months at a time, allowing for future missions without recharging its batteries.

ABE was developed by a team of engineers, who assembled what might be called the robot's body (frame and housings), muscles (thrusters), nerves (cabling and power to operate the motors, cameras, and sensors), and brain (computer systems for powering up

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and down and to determining where ABE should go and when to take measurements). Each of these components presented a complex design challenge. The final design allows scientists to program ABE to maneuver independently in three dimensions, and at a range of speeds. These features allow ABE to follow the contours of underwater mountain ranges, fly around sheer pinnacles, and dive into narrow trenches.

ABE's primary data collection tools are housed in the lowest of its three torpedo shaped pods, which is sealed. The two upper pods are free flooded and contain glass flotation balls. Click image for larger view.

Currently, ABE follows a set of instructions placed in its memory before deployment, and its data is accessible only after the robot is recovered. However, its developers envision the not-too-distant day when underwater acoustic transmission systems will allow scientists anywhere in the world to receive video and data from ABE, and to control its movements and sampling from their home laboratories

ABE is often deployed for long hours at extreme depths. ABE can survey bottom environments at depths of 5000 meters with a variety of sensors and tools. ABE carries a full complement of scientific survey equipment including: conductivity and temperature probes, a depth recorder, video cameras, and a magnetometer to measure magnetic fields. ABE is also equipped with sonar for advanced mapping, as well as geological sampling tools.

To obtain samples from the sea bottom, ABE can be fitted with a device called a wax core sampler. Wax coring works by pressing a heavy weight with sticky wax on its bottom onto the seafloor. Rock or sediment stick to the wax and can be brought on board ABE's

tending ship at the surface. This process is improved using ABE's precise navigation and video documentation tools to record the sampling process and document the surrounding seafloor.

To ensure precise navigational control, ABE is outfitted with two separate and complementary navigational systems. In addition to bathymetry, ABE has handled the difficult job of “temperature mapping”. Hydrothermal vent fields are located by changes in water temperature, called plumes, due to the high volume of heated water created at vent sites. By swimming along a programmed track, ABE can record temperatures along way and produce a thermal map of an area. This gives scientists the ability to concentrate on “hot-spots” and reduces the time needed to do ship surveys of a plume field.

ABE costs approximately $3,000 per day to operate. While it is relatively inexpensive to operate ABE itself, each deployment requires mobilization to the site, technicians and engineers to maintain ABE as well as data managers to download ABE’s data banks for processing.

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Remotely Operated Platform for Ocean Science (ROPOS)

• Capable of operating to depths up to 5,000 meters

• 5,500 m of electrical-optical cable tether

• Tools: two digital video cameras; two manipulator arms that can be fitted with different sampling tools (stainless steel jaws, manipulator feedback sensors, rope cutters, snap hooks, core tubes); variable-speed suction sampler and rotating sampling tray; sonar; telemetry system

• Can also be outfitted with up to eight custom-designed tools such as a hot-fluid sampler, chemical scanner, tubeworm stainer, rock-coring drill, rock-cutting chainsaw, laser-illuminated, range gated camera, and downward-looking digital scanning sonar

• Wide variety of observation tools provides scientists with exceptional flexibility so they can quickly respond to new and unexpected discoveries

• A “typical” dive requires at least four people (and sometimes more): the “Hot Seat” scientist, pilot, manipulator operator, and data/event logger

ROPOS, is a remotely operated vehicle designed to carry out a wide range of scientific explorations at depths of up to 5,000 meters. ROPOS weighs 6,000 lbs. and measures 5 ft wide x 9 ft long x 7 ft high. The vehicle operates in two modes - deep and shallow water. For missions in deep water(350 - 5000 m depth), ROPOS is lowered to its target depth nestled inside a large steel cage weighing 11,000 lbs. When the cage arrives at the dive target, ROPOS exits the cage and operates freely on 300 ft of tether. For deep-water operations, ROPOS requires a vessel with an A-frame or crane capable of lowering and hoisting 14 tons or more; this is the combined weight of ROPOS, its cage, and the 5,500 m of electrical-optical cable tethering the entire system to its support ship. When deployed in shallow water (<350 m), ROPOS operates without its cage.

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Engineered for Exploration

While oceanographic exploration is, by its very nature, an expensive undertaking, the costs associated with deploying a deep diving submersible and providing for its support vessel are enormous. This was a major consideration for the engineers who designed the ROPOS; thus, the vehicle was built to maximize its research effectiveness on each and every dive. ROPOS carries a suite of "core" observation tools. These include two digital video cameras (one mounted on the vehicle, another mounted on the cage); two manipulator arms, each capable of lifting up to 600 lbs, that can be fitted with different sampling tools, such as stainless steel jaws, manipulator feedback sensors, rope cutters, snap hooks, and core tubes; a variable-speed suction sampler and rotating sampling tray; sonar; and a telemetry system. ROPOS can also be outfitted with up to eight additional custom-designed observation tools specific to each mission. This equipment can be installed in any one of its eight available hydraulic power packs. Examples of custom-designed tools include a hot-fluid sampler, chemical scanner, tubeworm stainer, rock-coring drill, rock-cutting chainsaw, laser-illuminated, range gated camera, and downward-looking digital scanning sonar. ROPOS’ ability to carry such a wide variety of observation tools on each dive provides scientists with exceptional flexibility, as they can quickly respond to new and unexpected discoveries on the sea floor.

All data collected by ROPOS are simultaneously transmitted to the vehicle’s pilot, a bank of video recorders, and a data-management recorder. The data-management recorder logs all of the observational and navigational data collected during a dive, and keeps the pilot apprised with a continuously updated readout of the ship, cage, and vehicle positions. While ROPOS is designed to be relatively easy to operate, the amount of information dispatched during a "typical" dive requires at least four people (and sometimes more) to be present in the control room. These four individuals are the "Hot Seat" scientist, pilot, manipulator operator, and data/event logger.

.Schematic image of ROPOS and its full complement of support equipment used during a deep water deployment.

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General Purpose Remotely Operated Vehicles (ROVs)

• Depth capability varies

• Operated by one or more persons aboard a surface vessel

• Linked to the ship by a group of cables that carry electrical signals back and forth between the operator and the vehicle

• Tools: most are equipped with at least a video camera and lights

• Additional equipment may include a still camera, a manipulator or cutting arm, water samplers, and instruments that measure water clarity, light penetration, and temperature.

• Also used for educational programs at aquaria and to link to scientific expeditions live via the internet

• Range in size from that of a bread box to a small truck

• Often kept aboard vessels doing submersible operations for safety, and so the ROV can take the place of the submersible when it cannot be used because of weather or maintenance problems

• Can also be used to investigate questionable dive sites before a sub is deployed to reduce risk to the subs and their pilots

Remotely operated underwater vehicles (ROVs) are unoccupied, highly maneuverable underwater robots operated by a person aboard a surface vessel. They are linked to the ship by a group of cables that carry electrical signals back and forth between the operator and the vehicle. Most are equipped with at least a video camera and lights. Additional equipment is commonly added to expand the vehicle’s capabilities. These may include a still camera, a manipulator or cutting arm, water samplers, and instruments that measure water clarity, light penetration, and temperature. First developed for industrial purposes, such as internal and external inspections of pipelines and the structural testing of offshore platforms, ROVs are now used for many applications, many of them scientific. They have proven extremely valuable in ocean exploration, and are also used for educational programs at aquaria and to link to scientific expeditions live via the internet.

Deployment and Maneuverability ROVs range in size from that of a bread box to a small truck. Deployment and recovery operations range from simply dropping the ROV over the side of a small boat to complex deck operations involving large winches for lifting and A-frames to swing the ROV back

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onto the deck. Some even have “garages” that are lowered to the bottom. The cabled ROV then leaves the garage to explore, returning when the mission is completed. In most cases, however, ROV operations are simpler and safer to conduct than any type of occupied-submersible or diving operation. The disadvantages of using an ROV include the fact that the human presence is lost, making visual surveys and evaluations more difficult, and the lack of freedom from the surface due to the ROV’s cabled connection to the ship. The S2 Phantom ROV highlighted here has been rated to an operating depth of 2,400 ft. The vehicle has four thrusters that each provide one-half horsepower of thrust for horizontal, lateral, or vertical movement. Two of the thrusters are mounted horizontally. They allow the vehicle to move forward and backward, and to turn left and right. The other two thrusters are mounted at an angle, slanted in opposite directions. They provide vertical thrust (when both spin in the same direction) and lateral thrust (when they spin in opposing directions, one pushing water up, the other pushing it down). An ROV operator controls the vehicle from a system on board the ship. Using a joystick, a camera control, and a video monitor, the operator moves the vehicle and the camera to desired locations; the operator’s eyes essentially “become” the camera lens. The vehicle’s depth, heading, and geographic position (latitude and longitude) are also recorded.

Multiple Uses ROVs are often kept aboard vessels mounting submersible operations for several reasons; the first is safety. In the event that a submersible becomes entangled or otherwise incapacitated, an ROV can investigate the scene to help the operators decide how to respond. If appropriate, cutter blades can be attached to the manipulator arm and used to free the sub. If a sub loses power and cannot surface, the ROV’s manipulator arm can grab onto the sub. The deck crew can then bring the sub to the surface. ROVs also support exploration and science objectives. When the submersible cannot be used because of weather or maintenance problems, the ROV often can take its place. It can also be used to investigate questionable dive sites before a sub is deployed, limiting risk to the expensive subs and their pilots.

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Hercules

• Capable of operating to depths of 4,000 meters

• Pilots operate Hercules via a long fiber-optic cable

• Designed primarily to study and recover artifacts from ancient shipwrecks

• Tools: High-Definition (HD) video camera; pair of still cameras to accurately measure the depth and area of the research site and to create “mosaics”; sensors for measuring pressure, water temperature, oxygen concentration, and salinity

• Hydraulic thrusters—propellers in fixed ducts —control the ROV’s movements

• Yellow flotation package makes Hercules slightly buoyant in seawater

• Components that are not in pressure housings are immersed in mineral oil, which does not compress significantly under pressure

• Operates in tandem with tow sled “Argus”

• 30 meter (100 foot) tether connects Hercules to Argus

• Argus carries an HD video camera similar to the one on Hercules, as well as large lights that illuminate the area around Hercules.

• Generally operates 24 hours a day while at sea, different teams called “watches” take turns operating the vehicle

• Six watch-standers on each watch:

• Watch Leader makes sure that the scientific goals of the dive are being addressed; Pilot operates Hercules, controlling its thrusters, manipulator arms, and other functions; Engineer controls the winch that moves Argus up and down, as well as Argus’ thrusters and other functions, and assists the Pilot; �avigator monitors the work being done and the relative positions of the vehicles and ship and communicates with the ship’s crew to coordinate ship movements; Video and Data watch-standers

record and document all the data that the vehicles send up from the deep

• Little Hercules replaces Hercules for some missions; Little Hercules has no arms or tools, only gathers video images

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Hercules carries an array of cameras and acoustic sensors that are used to gather video and other data during each dive. Most important, a High-Definition (HD) video camera allows scientists to closely examine the dive site and monitor operations using very high resolution video. A pair of still cameras can be used to accurately measure the depth and area of the research site, and to create "mosaics", large images built up from many smaller images. Other sensors measure pressure (which gives depth), water temperature, oxygen concentration, and salinity.

While Hercules was designed to support archaeology and other scientific missions, in many respects it is a fairly conventional "work class" ROV, very like those used to service oil rigs and underwater pipelines. It is comprised of an open aluminum frame that holds most of the components. A cylindrical titanium pressure case 12 inches in diameter and 52 inches long holds most of the vehicle's electronics. Hydraulic thrusters -- propellors in fixed ducts -- control the ROV's movements. A bright yellow flotation package supports the rest of the vehicle when it is in the water, and drops the average density of Hercules to just a little less than the density of seawater. This makes Hercules just slightly buoyant, so it will float on the surface, but a small force generated by the vertical thrusters can drive the ROV up or down. The flotation package is made of "syntactic foam", composed of tiny, hollow glass balls mixed into epoxy resin. The foam is pretty heavy -- it has a density about half that of seawater -- but it can withstand the pressure exerted at a depth of 4,000 meters (more than 6,000 psi). The density of this foam is about the same density as pine or other softwood lumber. Hercules had to be designed to withstand the enormous pressure at its maximum depth. Most of the vehicle's on-board electronics are built into cylindrical titanium pressure housings. Any air exposed to the outside pressure will be compressed to one four-hundredth of its original volume, which can destroy other components in the process. To avoid this, the vehicle's electrical components that are not in pressure housings are immersed in mineral oil, which does not compress significantly under pressure, and does not conduct electricity or cause corrosion like seawater. Electric motors, transformers, electrical junction boxes, and much of the external wiring are filled with oil. Hercules also uses the same oil, driven by a hydraulic pump, to activate its arms and thrusters. Pilots aboard a support ship operate Hercules via a long fiber-optic cable that transmits operator commands, video, sensor data, and electrical power. The thrusters, commanded by the ROV pilot, move Hercules through the water

Hercules always operates in tandem with another vehicle, Argus. Referred to as a "tow sled", Argus dangles at the end of a cable from the ship. Because Argus lacks a buoyancy module and is built of heavy stainless steel, its movements are controlled by moving the ship or raising and lowering the cable. A short 30 meter (100 foot) tether connects Hercules to Argus, but it is usually kept slack so Hercules can move around without being pulled by the ship. Argus carries an HD video camera similar to the one on Hercules, as well as large lights that illuminate the area around Hercules. Argus allows the pilots and scientists to view Hercules' surroundings from above. Thrusters on Argus control its heading, so the pilots can aim the video cameras and lights toward Hercules and sites of interest.

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Tiburon (ROV”)

• Capable of operating to depths of 4,000 meters

• Controlled from a special control room on board its tender vessel, the R/V Western Flyer

• Tether contains electrical wires and fiber-optic strands

• Electrical thrusters and manipulators, rather than hydraulic systems, allow vehicle to move quietly through the water, causing less disturbance to animals being observed

• Variable buoyancy system allows the vehicle to float motionless in the water without the constant use of the thrusters

• Lower half of the vehicle is a modular toolsled, which can be exchanged with other toolsleds to carry out specific missions: benthic (or bottom) toosled has an extra manipulator arm and extensive sample-carrying space for geological and biological samples; “midwater” toolsled used to explore the biology of open ocean creatures; rock coring toolsled has been used to take oriented rock cores from the seafloor.

The remotely operated vehicle (ROV) Tiburon is a unique ROV, designed and built by the Monterey Bay Aquarium Research Institute specifically for scientific exploration of the deep sea. Since its first dive in 1997 the Tiburon has made over 400 dives, and has played an essential role in helping scientists make several important biological, geological and oceanographic discoveries. With a maximum operating depth of 4,000 meters, the Tiburon is capable of diving in all areas of the Monterey Submarine Canyon, and can access numerous sites of scientific interest worldwide. Such sites include undersea volcanoes in the mid-Pacific, deep-sea hydrothermal vents along the East Pacific Rise, the Juan de Fuca Ridge, and the Guaymas Basin in the Sea of Cortez. The Tiburon is controlled from a special control room on board its tender vessel, the R/V Western Flyer. It receives power and control signals from the surface via a long cable or “tether,” which contains both electrical wires and fiber-optic strands. Data from sensors and video signals from the ROV’s cameras travel back up the tether to the control room, where they are displayed on a series of monitors.

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A detailed image of the sensors and sampling tools on the ROV Tiburon. Because the Tiburon relies upon electrical thrusters and manipulators, rather than hydraulic systems, it is able to move quietly through the water, causing less disturbance to the animals being observed. This “stealth” ability is enhanced by the use of a “variable buoyancy system,” which allows the vehicle to float motionless in the water without the constant use of the thrusters. The lower half of the Tiburon is a modular toolsled, which can be changed out quickly with other toolsleds to carry out specific missions. For example, the benthic (or bottom) toolsled which has an extra manipulator arm and extensive sample-carrying space for geological and biological samples. Other toolsleds include a “midwater” toolsled for exploring the biology of open ocean creatures, and a rock coring toolsled which has been used to take oriented rock cores from the sea floor. The combination of flexibility, speed and safety offered by the Tiburon makes it an extraordinarily useful tool for deep-sea exploration.

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RCV - 150

• Capable of operating to depths 914 meters

• Tethered to support ship via a do armored electro-optical umbilical

• Tools: color video camera, 1500 lighting, micro conductivity/temperature/depth sensor, sonar, manipulator with a six inch cutoff wheel

• Controlled by a single pilot from a control console located in the tracking room of the support ship

• Small size compared to a submersible allows ROV to have high maneuverability; can get close to the bottom and allow the cameras to peer under ledges and into nooks and crannies

• Much easier to launch and recover than a human-occupied submersible so it can be used at night while the sub is being serviced

• Primary data collected is in the form of video

• Has been used to conduct surveys of bottom-fish in Hawaii

• In the event of a submersible emergency with one of the Pisces submersibles in water depths less than 3000 ft, the first action after notifying rescue assets would be to deploy the ROV-150 to evaluate the nature of the emergency and if entangled, try to free the sub with the radial cutter

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The RCV-150 is a tethered remotely operated vehicle with an operating depth of 914 m (3000 ft). The RCV-150 system consists of a dedicated winch/A-frame tether management system (TMS) and vehicle. The TMS/vehicle are deployed from the support ship via a double armored electro-optical umbilical to the desired operating depth. The vehicle is then launched from the TMS and operated on a 90 m (300 ft) tether. Standard vehicle equipment includes a color video camera with zoom and focus controls, 1500 watts of lighting, micro CTD, Tritech imaging sonar, and a simple manipulator with a six inch cutoff wheel. The TMS is equipped with lights and video cameras to aid in vehicle navigation and terrain monitoring from a position above the vehicle. The RCV-150 is controlled by a single pilot from a control console located in the tracking room of the support ship. The small size of the ROV (in comparison to a submersible) allows it to have high maneuverability. It can get close to the bottom and allow the cameras to peer under ledges and into nooks and crannies. The ROV is much easier to launch and recover than a manned submersible so it can be used at night while the sub is being serviced. The ROV can be launched several times within a night, allowing for a large geographical area to be covered. The primary data that is collected with the RCV-150 is in the form of video. One of the common uses of the RCV-150 has been to conduct surveys of bottomfish in Hawaii. All of the fish “seen” by the ROV are counted and recorded and then the video serves as a relatively long-term record of the appearance of the dive site. In the event of a submersible emergency with one of the Pisces submersibles in water depths less than 3000 ft, the first action after notifying rescue assets would be to deploy the RCV-150 to evaluate the nature of the emergency and if entangled, try to free the sub with the radial cutter.