The Joint Land Attack Cruise Missile Defense Elevated Netted Sensor System (JLENS) is an Army program consisting of an orbit of two aerostats that are tethered to a fixed site. It provides persistent capability to detect cruise missiles, UAVs, and aircraft, and provides targeting information for interceptors. A JLENS orbit also has a secondary capability to detect vehicles and surface ships and can operate at altitudes of up to 10,000 feet, which gives them significant range. They are deployed with a mobile mooring station to secure the tether and hold the unit in place. The tethers also provide radar control and data links to ground stations.1
The sensor has a 360-degree field of vision and can track multiple threats simultaneously up to a range of 340 miles. One aerostat in the orbit functions as a surveillance radar while the other one performs fire control functions. The surveillance radar operates at Very High Frequency band allowing it to scan over a wide area, while the fire control radar operates in the X-band to provide a precise picture of the threat to the shooters.2 Through testing, it has proven its ability to integrate with both Standard Missile-6 and PATRIOT interceptors.3
The program was initiated in the late 1990s and began flight testing at Dugway Proving Grounds in Utah in 2010. At the time, plans called for the Army to procure 14 systems. However, program director Dean Barten suggested that number would come down but that “half a dozen systems” would be the “absolute minimum.”4
In January 2015, JLENS began a three-year operational exercise based out of Aberdeen Proving Grounds in Maryland operating in defense of the National Capital Region in order to decide whether to purchase more than the two orbits currently procured.5
In October 2015, the fire control aerostat broke free from its mooring due to particularly strong winds. Because of a failure in its automatic deflation device, the aerostat floated through rural Pennsylvania, eventually landing in Moreland Township.6
An investigation into the incident found that it was caused by a loss of pressure that caused the aerostat to become unstable. This, combined with high winds, caused the tether to break.7
As a result of the October 2015 incident, funding for the program was reduced in the FY 2016 Omnibus spending bill. In March 2016, Congress denied an Army request to reprogram more money to make up the deficits. Despite these setbacks the FY 2017 President’s Budget included continued program funding after Secretary of Defense Ashton Carter approved resuming the program.8
- Office of the Director, Operational Test and Evaluation, “FY 2013 Annual Report,” http://www.dote.osd.mil/pub/reports/FY2013/pdf/army/2013jlens.pdf.
- Amy Butler, “JLEN Data To Finally See Operational Use for NORAD,” Aviation Week, December 18, 2014, http://aviationweek.com/defense/jlens-data-finally-see-operational-use-norad.
- Pat Hindle, “JLENS Completes Field Testing,” Microwave Journal, July 26, 2013, http://www.microwavejournal.com/blogs/9-pat-hindle-mwj-editor/post/20290-jlens-completes-field-testing.
- “Anti-Cruise Missile Aerostat Testing Begins,” Aviation Week, June 2, 2010, http://aviationweek.com/awin/jlens-anti-cruise-missile-aerostat-testing-begins.
- Amy Butler, “JLENS Data To Finally See Operational Use for NORAD,” Aviation Week, December 18, 2014, http://aviationweek.com/defense/jlens-data-finally-see-operational-use-norad.
- David Willman, “Missing batteries among issues that caused Army’s runaway blimp,” Los Angeles Times, February 14, 2016, http://www.latimes.com/nation/la-na-runaway-missile-defense-blimp-20160214-story.html.
- Jen Judson, “After Blimp’s Wild Ride, JLENS Program Will Fly Again, NORAD Says,” Defense News, February 11, 2016, http://www.defensenews.com/story/breaking-news/2016/02/11/runaway-blimp-jlens-program-fly-again-norad/80241204/.
- Tom Karako and Ian Williams, “JLENS Future Bleak, But Need for Capability Remains,” Center for Strategic and International Studies, April 5, 2016, http://csis.org/files/publication/160405_Karako_JLENS_Web.pdf.