The military blimp that finally touched down in Pennsylvania today after breaking from its moorings is part of a $2.7 billion test program known as JLENS, which the Pentagon has developed to detect low-flying drones and cruise missiles.
The Joint Land Attack Cruise Missile Defense Elevated Netted Sensor System is more commonly known by the acronym JLENS.
The idea for the program is a simple one: Two stationary helium-filled blimps nearly 80 yards long each carry sophisticated radar systems that can provide 360-degree surveillance for low-flying weapons systems that could pose a threat.
One of the blimps carries a surveillance radar system with a 360-degree field of view that can track incoming objects. The other blimp carries an X-band "fire control" radar that can more precisely target the track of an "object of interest" followed by the surveillance radar.
The blimps can go as high as 10,000 feet and remain in place for as long as 30 days via a tether that provides it with power and transmits the radar data to ground systems.
The one that broke from its moorings at the Army’s Aberdeen Proving Ground in eastern Maryland was the one carrying the surveillance radar.
The blimps are the final result of a much-delayed project that has ballooned in cost and remains in the testing phase.
“The program cost is $2.7 billion in Operations & Maintenance funding and for research funding,” said Maj. Katrina Andrews, a spokeswoman for Continental U.S. NORAD Region (CONR).
Earlier this year, JLENS entered a three-year operational testing phase at Aberdeen where its data would be integrated into the larger air defense systems for Washington, D.C.
But it was not linked to those systems in April when a Florida man landed a gyrocopter on the grounds of the U.S. Capitol undetected by conventional radar systems. Military officials said at the time that the JLENS would have likely picked up the pilot’s approach.
The sophisticated radar can also spot and track vehicles on the ground and water like tanks, boats, trains and vehicles.
In a fact sheet, Raytheon, the blimp’s maker, minimized the potential that the JLENS tether could break.
“The chance of that happening is very small because the tether is made of Vectran and has withstood storms in excess of 100 knots,” the fact sheet says. “However, in the unlikely event it does happen, there are a number of procedures and systems in place which are designed to bring the aerostat down in a safe manner. “
That includes an automatic deflation system that is designed to deflate the blimp should it go astray, but a NORAD spokesman said today it was unclear whether the system is what deflated the blimp to bring it down in Pennsylvania.
As the investigation into how the blimp broke off from its moorings continues, the testing program has been put on hold. The other blimp that remained tethered at Aberdeen has been grounded until further notice.