January 10, 2008

Hi:

My name is Jenisteen and I go to Jonas Clarke Middle School in Lexington, Massachusetts. I want to ask the engineers a question. When you first saw all the wires on the AUV did you ever feel like you were going to mess it up, nervous or were you really excited to experiment on it?

Thank You. Have fun:)

Hello Jenisteen,

My name is John Bailey. I do a lot of the electrical work on Jaguar and Puma. Sometimes I'm a little nervous when I start working on something new. After working on Jaguar and Puma for a while, I got to know the wiring inside and out.

During the first few weeks, I worked slowly and carefully, documenting everything along the way. Now, every wire on the vehicles is documented. Before working on any of the circuits, I make sure I have my documentation in front of me first.

Now I have fun when I work on the vehicles. They don't make me nervous anymore.

Dear Scientists,

When is your next dive going to be? How are the AUVs doing? Are they mashed up after the road trip? How successful do you think this trip is going to be?

From
Abby Peterson & Sintra Reves-Sohn
Falmouth, MA

Dear Abby and Sintra:

As I reply to your questions, Puma is on its way to a water depth of 3450 meters. If all goes well, it will then do a survey “sniffing” for hydrothermal plumes.

The AUVs had some damage from their road trip, but our engineers had a spare for a broken propeller and were able to repair the other damage.

How successful will the trip be? Well, you never know, but we are all working hard to get as much out of the trip as possible.

Thanks for the question.

Susan Humphris

Hello, I am a student in Ms. Shields's seventh grade class in Lexington, MA, and I have a question about Puma. How many different prototypes did you have before you agreed on the final design of Puma?

Thank you,

Puneet H.

Dear Puneet:

That is a very good question! There was one AUV of similar design with two hulls (or pontoons) that Hanu Singh and his colleagues built before Puma and Jaguar. Prior to that, most AUVs were torpedo-shaped with one hull. The AUV that is similar is called SeaBed and it was built to swim about 2.5 meters (8 feet) off the bottom to do underwater photography. It has been used to, for example, make photomosaics (many individual photographs pieced together) of coral reefs and shipwrecks.

I hope you will continue to follow our cruise for the next week!

Susan Humphris

Divediscover,

I am one of Miss Sheild's students at Clarke Middle School in Lexington, MA. After viewing pictures of Puma and Jaguar, I have a question. Why did the scientists build Puma and Jaguar with two medium-sized cylinder-shaped compartments instead of just one like other AUVs? Wouldn't just one compartment make it easier to maneuver?

Matthew

Dear Matthew:

Very observant! The reason that Puma and Jaguar have two cylinders (or hulls) is to make them more stable. AUVs with one hull are very efficient at driving around and surveying, but if you want the AUV to hover like a helicopter, it needs to be stable and not roll around. So Puma and Jaguar have two hulls. The bottom one contains all the heavy things, such as batteries, while the top one contains the “brains” (computers and flotation). In addition, Jaguar is our vehicle that takes photographs of the seafloor. It would be much more difficult for a single-hull AUV to remain stable enough to do this without rolling.

Keep Dive and Discovering!

Susan Humphris

Hi,

My name is Meredith and I go to Beckwith Middle School. My class and I have been learning about hydrothermal vents. We learned that they can shoot out very hot water, so how do you get so close to them as to get samples?

Hi Meredith:

Glad to hear you are learning about hydrothermal vents! You are right – the fluids that come out of them can be very hot, and can reach temperatures of 350°C to over 400°C (660°F to over 750°F)! At present, AUVs cannot take samples, but when we sample fluids from vents with a human-occupied submersible or a remotely-operated vehicle, we use a special bottle made of titanium that has a long snorkel on it that we can stick down into the top of the chimney.

Nevertheless, we still have to get only a few feet away from the chimney to do this. Why is this possible? Well, imagine having a narrow jet of very hot water shooting into a bathtub of very cold water. You could put your finger quite close to the hot water jet because its heat is lost quickly to the surrounding cold water.

I hope that answers your question – thanks for following along!

Susan Humphris

Good afternoon, My name is Garni Aroyan and I am a student at Clarke Middle School in Lexington, MA in Ms. Sheild's Science class.

My question for you is: How are the robots, Jaguar and Puma, able to withstand the water pressure?

Thank you for your time, Garni Aroyan

Good morning, Garni:

That is a good question! When you look at the vehicles, you might think that each hull is a solid structure that encloses all the components in some sort of big pressure housing. But in fact, the outside is a fiberglass “skin” that acts mainly as a protective covering. Things like flotation are strapped to the upper hull and are exposed to seawater. However, all the components, such as the computers that provide the “brains” to the AUVs, are contained in housings made of a special type of aluminum that is strong enough to withstand the pressure as the vehicle descends in the water.

Thanks for sending a question.

Susan Humphris

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