The U.S. Army is floating a football field-sized, blimp-like aircraft 10,000 feet above Maryland to protect Washington and much of the east coast from military attacks.
Bearing the memory-taxing name of "Joint Land Attack Cruise Missile Defense Elevated Netted Sensor System," or JLENS for short, the 74-meter long balloon is one of the latest tools made to track drones or missiles headed for targets in the United States. Defense contractor Raytheon built the craft and the Army launched it for testing near the nation's capital on December 27. A second balloon will launch in early 2015.
Both are equipped with radar powerful enough to monitor a Texas-sized swath of airspace for potential drone or missile strikes.
Though it looks like a blimp, it is technically an "aerostat"—a balloon tethered to the ground by a thin cord. The tether is only 1 1/8 inches thick, but it can withstand winds of 100 knots (more than 100 miles per hour), according to Raytheon representative Mike Nachshen. A material called Vectran makes the cord strong, and fiber optic cables within it deliver power and take in data from the aerostat's computers. The cord allows the balloon to float for about a month before it needs to be grounded for maintenance.