Photos: Unmanned vehicles take to air, land and sea

This robot doesn't fly, but it does swim. The intended mission of this autonomous underwater vehicle (AUV), called the Fetch 3.5, is to sense and record various information about the seas.

Weighing in at 215 pounds, with an 83-inch length and 13.5-inch diameter, it's designed to be small and lightweight enough to be launched from smaller or rigid-inflatable boats. The robot is engineered by a small company called Sias Patterson, which was acquired in 2005 by Baltimore-based Prizm Advanced Communication Electronics. It can handle missions up to 30 hours long and can plunge to depths as low as 500 feet. A University of Delaware professor recently signed up to use the instrument for research and teaching activities at the school's relatively new Coastal Sediments Hydrodynamics and Engineering Laboratory.