Comment Re:Re tasking (Score 1) 67
You do understand the United States has had a very significant interest in underwater vehicles approaching it's shores, right?
Indeed they do. But I'd imagine these things are pretty quiet.
FTFA:
[...] 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.
I would imagine these things are pretty quiet. Run them about 50 feet underwater and I doubt the government would be able to hear them.
Not too quiet. To determine navigation AUVs usually use forms of sonar. That and since this is an "experiment" it should have a pinger - other commercial scientific AUVs do so you can recover if there is a glitch.
