Air defense blimps put on guard along the East Coast

Starting next spring, and continuing for another three years, commuters on the Interstate 95 corridor will have to get used to seeing something new in the skies north of Baltimore: twin 250-foot blimps floating placidly at 10,000 feet, tethered to the ground like a couple of children’s balloons.

The blimps, part of a U.S. Army program to detect and track cruise missiles and other threats, will be participating in a three-year Northern Command (NORTHCOM) homeland defense exercise taking place along the U.S. East Coast. The first of the two blimps, or aerostats, will be launched this week at Aberdeen Proving Ground, about 25 miles northeast of Baltimore.

The system, called JLENS (short for Joint Land Attack Cruise Missile Defense Elevated Netted Sensor System), will carry two different types of radar systems designed to work in tandem. A surveillance radar in one blimp detects and tracks incoming missiles. The other is a precision fire control radar that can feed targeting data to fighter jets or ground-based air defense missiles. Floating at an altitude of 10,000 feet gives the system an over-the-horizon surveillance capability that ranges from upstate New York to Norfolk, Va., and as far west as Ohio.

“If I can detect this thing much further out, it gives commanders [more] time to get air assets into place and to alert people on the ground of the threat,” said Maj. Gen. Glen Bramhall, commander of the 263rd Army Air and Missile Defense Command, in an Army statement. “If I can give a command four more minutes or five more minutes, that’s a lot of time.”

Although cruise missiles launched from submarines or converted, clandestine civilian ships could pose a threat to the East Coast, homeland defense wasn’t this system’s original mission. The tandem blimps were developed by the Army to provide early warning protection for American and Allied bases around the world. They were envisioned as a cheaper alternative to manned aerial surveillance aircraft carrying AWACS (Airborne Warning And Control System) radars.

But the NORTHCOM homeland defense exercise may be a last shot for the blimps to prove their worth. The program has gone through a series of delays, cost overruns, and unreliable results and was cut back from 32 blimps (at a cost of $180 million each) to just two, according to a report on the Popular Mechanics website.

A 2013 Pentagon report on the program stressed that its testing to that point had been limited in scope and that, “no testing [had] occurred in an operationally realistic over-water environment,” which prompted the Joint Staff to order the program’s participation in the NORTHCOM exercise.

The U.S. Northeast corridor’s busy airspace will give the system a chance to operate in a real world environment and may be a good test of its ability to discriminate a missile threat from other objects. The 2013 Pentagon report noted the system has had a difficult time with this task, suffering from “non-cooperative target recognition, friendly aircraft identification capabilities, and target track consistency.”

Although some groups have expressed privacy concerns about the surveillance blimps, Army officials insist the system carries no weapons, cameras, or video equipment.

The Associated Press contributed to this report.