Researchers at New Jersey Institute of Technology (NJIT) are putting a 21st century spin on a 19th century technology to make the nation's ports and coastal waters safer. Airships — known today mainly for advertising flyovers at football games — are the core of a new coastal surveillance system in development for the Missile Defense Agency (MDA) of the U.S. Department of Defense. But the new models will bear little resemblance to their predecessors. These High Altitude Stratospheric Airships (HASAs) will be unmanned, stationary platforms 14 to 16 miles above the ground. At 500 feet long and 150 feet in diameter with a volume of 5 million cubic feet, the HASAs will be 25 times the size of a Goodyear blimp.