Philippine Sea

Sunday, February 20, 2011

Sunday Ship History: Robot "Glides" Across the Atlantic and Beyond

Rutgers "Gliding" Robot (Rutgers U. photo)
Maybe you missed the story at the time, but a group of Rutgers University research successfully piloted a robot "glider" across the Atlantic Ocean on a multi-month journey that took the eight foot ling research robot from the U.S. coast to Spain. The experiment ran from launching on April 27, 2009 to December 4, 2009.

More on the journey at Flight Across the Atlantic - Scarlet Knight. What's an underwater "glider?" As explained on the Rutgers' web site:
Most underwater vehicles, like submarines, use a spinning propeller to move around in the water. Propeller driven vehicles are fast, but they also require a lot of energy to maintain their speed. Smaller vehicles like the glider only carry enough battery power to drive a propeller for a few days at most.

Instead, underwater gliders move around by changing their buoyancy, that is they change their density such that they alternate between more dense and less dense than the surrounding ocean water. This change in buoyancy causes the glider to rise and sink in the ocean. The glider changes its density by moving a small piston forward and back that increases and decreases its volume. You may remember that you can calculate the density of an object by taking its mass and dividing that by the object's volume. Since the mass of the glider remains constant, all we need to do is change its volume. A small change in volume (about a half cup of water) is all the glider needs to change its density enough to rise and sink in the ocean.

As the glider goes up and down, its wings give it a forward motion just like the wings on an airplane glider, which is why these robots are also called gliders. But airplane gliders can only "glide" as they fall downwards due to gravity. Underwater gliders can glide forward both as they rise and fall.
Path of the "Scarlet Knight" (Rutgers U. image)
It took 7 months for the "Scarlet Knight" to make the crossing, all the while promoting new techniques of gathering information about the ocean.

The Rutgers University site has video, photos and much more about this historic effort.

According to the Smithsonian Institute, the glider will be on display in the Sant Ocean Hall, Natural History Museum, Washington until mid-2012.

NOAA reports that some of the technology demonstrated during the mission was deployed during the Gulf Oil Spill:
“Gliders sample the ocean in places it is impractical to send people and at a fraction of the cost,” said Zdenka Willis, director of the U.S. IOOS Program. “Using robots to collect scientific data is the wave of the future in terms of ocean observing.”

Gliders collect data such as temperature, salinity, currents and density that describe conditions below the surface of the sea and at varying depths.

As part of the Deepwater Horizon BP oil spill response effort, IOOS partners deployed a fleet of gliders equipped with sensors to help indicate the presence of oil. Although scientists must still confirm the oil through water sampling, the gliders narrowed the search zone for subsurface oil.
Now, that's a science project.

And a bit of history.

1 comment:

  1. Anonymous5:46 AM

    Any chance of a salvage claim if you happen to come across this thing in the ocean?

    ReplyDelete