Fighter jets are tracking a US military blimp that broke loose and is floating across the country

A US military blimp, part of a twin multi-billion surveillance program tethered outside of Washington, DC, has broken loose and is now floating across the northeast region of the US.

The blimp is part of the JLENS program - Joint Land Attack Cruise Missile Defense Elevated Netted Sensor Systems.

The blimp, part of a pair built by Raytheon, was responsible for defending against possible cruise-missile attacks and other potential threats to Washington, DC, and other East Coast cities through the use of high-detailed radar imaging.

However, the airship detached from its tether outside of the Aberdeen Proving Ground in Maryland at approximately 11:54 a.m. on Wednesday, a spokesman for the installation told The Baltimore Sun.

Currently, The Sun notes, the blimp is floating over Pennsylvania. Two F-16s have been scrambled to follow the blimp and help map its traffic to ensure that it does not interfere with civilian air traffic.

The blimp has an estimated 6,000 feet of cable dangling from behind it.

The two JLENS blimps were designed to operate in concert. One of them provides constant 360-degree scanning, covering a circular area from North Carolina to central Ohio to upstate New York, even as the blimp remains stationary over suburban Baltimore. The other focuses on more specific targets. Together, the blimps track missiles, aircraft, and drones in a 340-mile radius.

As of the end of 2014, the JLENS project cost the US government $2.8 billion. Additionally, Congress had approved another $43.3 million for the first year of the JLENS operational test.