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America's new military...blimps?

JLENS about to launch.
Raytheon
JLENS about to launch.

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.

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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.

"It is basically a giant USB cord," Nachshen said. "That is simplifying it, but it works in a similar way. It is kind of the JLENS's secret sauce."

There are no cameras or weapons on the craft—it can only track large metal objects, such as planes and missiles. It can "see" in 360 degrees over a 340 mile distance, giving an considerable warning of any attack.

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"JLENS can detect potential threats at extremely long ranges, giving North American Aerospace Defense Command more time to make decisions and more space to react appropriately," said Dave Gulla, vice president of Raytheon Integrated Defense Systems' Global Integrated Sensors business, in a report announcing the tests.

During the tests, the JLENS will be used both by the army and NORAD—a joint missile defense program shared by the US and Canada. After the Army finishes its tests on the blimp, it will turn it over to the soldiers of the U.S. Army's A Battery, 3rd Air Defense Artillery.