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12 novembre 2015 4 12 /11 /novembre /2015 08:20
Photo: U.S. Northern Command

Photo: U.S. Northern Command


November 11, 2015: Strategy Page


On October 28th a JLENS (Joint Land Attack Cruise Missile Defense Elevated Netted Sensor) blimp undergoing testing at a U.S. Army base in Maryland (north of Washington DC) broke loose and drifted for nearly four hours and 240 kilometers until the deflation device (for such emergencies) activated and brought the blimp down. Because the blimp was dragging about 2,200 meters of tether (the cable that keeps the blimp in one place) some 26,000 civilians in its path (rural Maryland and Pennsylvania) lost electrical power for hours as the tether shorted out power lines. There were no injuries but all the damage and disruption is going to cost the army nearly $200 million. It is also likely to get the JLENS program shut down. While there have been JLENS type systems suffering runaway blimps in Afghanistan and Iraq, these did not make the news and were recovered and soon back in service. But a runaway blimp not far from the American capital is another matter. There were originally supposed to be 16 JLENS systems built by now but for a number of reasons there are only two and the other is in storage. JLENS technology has been useful even as JLENS itself has had many problems. The latest wandering blimp incident may prove fatal for JLENS.


Since the 1990s the U.S. Department of Defense has spent nearly $3 billion to develop JLENS a system that used tethered blimps to carry radars that could spot low-flying aircraft like helicopters, small planes and cruise missiles so that these targets could be attacked using missiles or autocannon, fired from the ground or the air, to destroy these hard to detect (using normal radars) targets. Even before the runaway JELENS there was a lot of political pressure to cancel JLENS because of failure to perform. Naturally it’s more complicated than that. While JLENS technology has proved very useful since September 11, 2001, there is concern that JLENS itself never achieved a high level of effectiveness and reliability in performing the task it was originally designed for. The manufacturer insists these accusations are baseless but it is true that JLENS has had several recent embarrassments when the system was not ready when needed or it was operational but did not spot the low flying threat or did spot it but could not tell if it was hostile.


One of the original uses JLENS was developed for was to help defend offshore oil facilities from attack by terrorist speedboats. This it was able to do after 2003 in Iraq. But in more crowded environments (like urban areas) JLENS spotted too many low flying objects but could not tell which ones were a threat and which were not. This has now become an issue because JLENS type systems are no longer in Iraq.


The JLENS system uses two 75 meter (233 foot) long, helium filled, unmanned blimp equipped with radar and other sensors. A JLENS blimp is about 2.5 times the size as the more familiar advertising blimp. Actually, the JLENS blimp is an aerostat, a blimp like vehicle designed to always turn into the wind and stay in the same place. The JLENS blimp is unpowered and secured by a cable (tether) that can keep the aerostat in position at its maximum altitude of 5,000 meters (15,000 feet). At that altitude the JLENS aerostat can carry a two ton payload. The cable also supplies power, which means the blimp can stay up for about 30 days at a time before it has to be brought down for maintenance on its radars. Two radars are carried in each aerostat. One is a surveillance radar, the other is a precision track and illumination radar (PTIR). The surveillance radar provides long-range coverage (over 300 kilometers, exact range is secret), while the PTIR, which is a steerable system capable of tracking multiple targets, can focus in on items of interest. Thus each JLENS can cover a huge area and can pass target data to airborne or ground based missile systems for interception.


A major JLENS success was using JLENS technology for similar systems defending bases in Iraq and Afghanistan from ground attack. While larger UAVs are popular, mainly for their persistence (the ability to stay in the air, over a particular area, for a long time) and some (Predator, Reaper and Global Hawk) can stay in the air for over 24 hours at a time, they still have to land regularly to be refueled or undergo maintenance. In Iraq the military found that "stationary UAVs" (helium filled aerostats or tall towers) not only do the job just as well but do it a lot cheaper (under $1000 an hour, mostly for maintenance, repairs, and personnel to monitor the sensors). Compare this to Predator, which costs $5,000 an hour to operate, and Global Hawk, which costs $25,000 an hour. Global Hawk is so expensive partly because of the high end sensors used. Not everyone needs the high flying Global Hawk or even a Predator. They just need a way to keep an eye on a large area (like a chunk of the Syrian, Iranian, or Pakistani border) 24/7. JLENS and its ground defense variant (RAID) are a much cheaper alternative and have become popular alternatives to mobile UAVs.


In 2004 the U.S. Army sent 22 blimps (aerostats, actually) to Iraq and Afghanistan to operate as part of RAID (Rapid Aerostat Initial Deployment) systems. These systems were based on JLENS. The blimps float at about 320 meters (a thousand feet) up, tethered by a cable that provides power and communications to the day and night cameras up there. The big problem is ground fire from rifles and machine-guns. Iraqis, in particular, like using the RAID blimps as targets. Rifle fire won't destroy the blimps but does cause them to be brought down more frequently for repairs. Bullet-hole repairs often have some of them coming down every few days. There are surveillance systems similar to RAID but mounted on tall steel towers. These also suffer gunfire damage, but rarely any that damage the equipment.


The first army blimp sent to Iraq in early 2004 was one of its JLENS systems. JLENS equipment was also modified to be mounted on a tower even though it was most effective when operating from the aerostat. JLENS sensors can not only detect and track low flying aircraft and missiles but also small boats and ground vehicles. Off the coast of Iraq it could detect hostile boats making a run for Iraqi oil facilities. JLENS has been used in Afghanistan as well. JLENS was still in development in 2002 but much of the tech was soon approved for mass production. In addition to providing 24/7 coverage for approaching cruise missiles JLENS can also provide a communications relay for other radars and weapons systems (anti-aircraft missiles and warplanes) to coordinate detection and destruction of cruise missiles.


The RAID systems (used on aerostats as well as towers) are much cheaper than JLENS, less than five million dollars each, and the army has bought over a hundred of them. When RAID aerostats operate at an altitude of a 320 meters their cameras can see out to about sixty kilometers. The smaller towers shorten that range quite a bit. The ten meter (30 foot) tower can see out to eleven kilometers, the 20 meter (60 foot) tower out to 16 kilometers, and the 27 meter (84 foot) tower out to 20 kilometers. The ten meter tower is adequate for most situations, which usually involve guarding a base. The JLENS and RAID systems are operated by air defense troops, often from the reserves or National Guard.


One of the two JLENS built is used for development. This included testing new capabilities being added to JLENS. In 2013 the army and air force successfully tested a new air defense capability by using its JLENS system to detect an anti-ship cruise missile and automatically pass the target data to an F-15 via its digital data link (Link 16), and enabling the pilot to launch an AMRAAM missile to intercept the incoming cruise missile. This is a major reason for the huge cost of JLENS; adding new capabilities and costs. This is a problem with most peacetime weapons development programs and JLENS is a good example of this bad habit.

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30 octobre 2015 5 30 /10 /octobre /2015 08:20
photo NORAD

photo NORAD


Oct 29, 2015 by NORAD


PETERSON AIR FORCE BASE, Colo. – This morning, recovery operations commenced for the Joint Land Attack Cruise Missile Defense Elevated Netted Sensor System (JLENS) fire control radar system aerostat.

Wednesday, at approximately noon EDT, the aerostat detached from its mooring station at Aberdeen Proving Grounds, Maryland. Around 4 p.m. EDT the aerostat grounded itself in a rugged, wooded area in northeast Pennsylvania. The aerostat landed in two separate but nearby sections; the tail and main body are separated by a quarter-mile. JLENS personnel in conjuction with Pennsylvania Army National Guard and Pennsylvania State Police secured the site, while a technical recovery team of military and civilian experts from Aberdeen Proving Ground, Maryland, deployed to the site.

After the fire control radar system aerostat detatched, the surveillance aerostat was immediately lowered and secured as a precaution.

An emergency operations center has been established in Pennsylvania and the crash sites are being assessed. Recovery efforts are underway.

The Army has initiated an investigation to determine the cause of the incident. There is no indication that it may have been cyber or terrorist-related. The investigation will look at every aspect of how this incident occurred. 

For questions regarding the recovery process contact the Continental U.S. NORAD Region (CONR) at  850-283-8080. For general questions about the incident contact North American Aerospace Defense Command and U.S. Northern Command Public Affairs.

JLENS is a supporting program of the Army and Joint Integrated Air and Missile Defense, providing persistent, over-the-horizon radar surveillance and fire control quality data on Army and Joint Networks.  It enables protection from a wide variety of threats to include manned and unmanned aircraft, cruise missiles, and surface moving targets like swarming boats and tanks. 

NORAD is the bi-national Canadian and American command that provides maritime warning, aerospace warning and aerospace control for Canada and the United States. The command has three subordinate regional headquarters: the Alaskan NORAD Region at Elmendorf Air Force Base, Alaska; the Canadian NORAD Region at Canadian Forces Base Winnipeg, Manitoba; and the Continental NORAD Region at Tyndall Air Force Base, Fla.

For more information about NORAD, refer to http://www.norad.mil.

Follow us on Facebook at http://www.facebook.com/noradnorthcom.

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26 juillet 2013 5 26 /07 /juillet /2013 07:20
The 74m long tethered aerostat of the joint land attack cruise missile defence elevated sensor system. Photo Army.Mil.

The 74m long tethered aerostat of the joint land attack cruise missile defence elevated sensor system. Photo Army.Mil.

25 July 2013 army-technology.com



The Raytheon-built joint land attack cruise missile defence elevated sensor (JLENS) system has successfully completed the US Army's early user testing (EUT), at an undisclosed location.


The six-week-long EUT evaluated the JLENS' ability to operate in a multitude of complex scenarios, simulated an operational environment.


In addition, the system demonstrated its long endurance through a 20 day continuous operation during testing, which paves the way for operational evaluation at Aberdeen Proving Ground in Maryland, US.


US Army JLENS product manager Dean Barten said the EUT completion confirmed JLENS' maturity and its readiness to be deployed according to soldier's requirements.


"With EUT under our belts, we are well on our way to deploying the system to Aberdeen Proving Ground for an operational evaluation, and ultimately, putting JLENS in the hands of the soldier," Barten said.


Raytheon Integrated Defense Systems business Global Integrated Sensors vice-president Dave Gulla said the completion follows a series of JLENS achievements, including detection of a ballistic-missile surrogate and enabling the intercept of cruise missile targets with the patriot and standard missile six.


"JLENS is essential to national security because it provides a proven capability against threats that no other system in the world offers," Gulla added.


Equipped with a powerful integrated radar system, JLENS is an affordable elevated, persistent over-the-horizon sensor system designed to detect, track and engage a broad range of distantly located threats in the battlefield.


The system primarily helps combatant commanders defeat a variety of threats including hostile cruise missiles, low-flying manned and unmanned aircraft, as well as moving surface vehicles, such as swarming boats, mobile missile launchers, automobiles and tanks.


Featuring two tethered, 74m aerostats that are networked to mobile mooring stations, and a communications and processing group, the system provides 24/7 surveillance coverage for 30 days, in addition to enabling ascent phase detection of tactical ballistic missiles and large-calibre rockets.

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8 avril 2013 1 08 /04 /avril /2013 16:35

rtn11 ids jlens img1


April 8, 2013 defense-aerospace.com

(Source: Lexington Institute; issued April 5, 2013)


It takes a crisis to concentrate the mind. Faced with unusually bellicose rhetoric from the regime in Pyongyang, the Obama Administration reversed course on National Missile Defense (NMD) and is rapidly bolstering its theater air and missile defenses in the region. The Department of Defense will add 14 ground based interceptor missiles to 30 currently in place at Fort Greeley, Alaska. Two Aegis missile defense capable destroyers have been sent to waters off the Korean peninsula.


Equipped with the Standard Missile 3 IA, these ships can provide defense against short to medium range ballistic missiles as well as advanced cueing for the NMD system. In addition, the Army is deploying a THAAD battery to Guam, an obvious potential target for a North Korean missile. In addition, the U.S. has deployed B-2 bombers and F-22 fighters to South Korea as shows of force.


Without appearing bellicose, there are additional capabilities that the U.S. could and should send to the region that would provide important intelligence collection and defensive capabilities. One of these is the Joint Land Attack Cruise Missile Defense Elevated Netted Sensor System (JLENS). This is a long-range surveillance system based on two large aerostats that carry radars, one for surveillance and the second to provide very precise intercept data. The aerostats can stay airborne for weeks at a time. Because it operates at a relatively high altitude and carries long-range sensors, JLENS can look out to about 550 km and track hundreds of targets at one time. We are not just talking about ballistic missiles or aircraft.


JLENS can track low flying cruise missiles, small boats and even ground vehicles all at the same time. In recent tests, JLENS demonstrated its ability to detect and track simultaneously-launched multiple ballistic missiles during their boost phase and also accurately locate their launch points. This last capability may be particularly important in finding North Korean mobile missile launchers. As a joint program, JLENS was designed from the start to support the missile and air defense operations of all the services. It carries a full array of communications capabilities allowing it to feed data to Army, Navy and Air Force units and platforms.


The on again/off again threat from North Korea is not the only danger U.S. and allied forces in the region face. On February 26, a Russian TU-22M Backfire bomber conducted a simulated cruise missile attack on a U.S. destroyer. The next day another practice attack was conducted against a missile defense site on Japanese soil. This is but one of dozens of such “exercises” in which Russian bombers simulate attacks on targets in Japan, NATO and even the continental U.S., on occasion penetrating into national airspace and having to be escorted out by armed fighters. It is beginning to look a lot like the bad old days of the Cold War.


Then there is the growing Chinese air and offensive missile threat. This includes hundreds of dual capable medium and intermediate range and ballistic and cruise missiles as well as the new DF-21 anti-ship ballistic missile intended to attack U.S. aircraft carriers. In addition, the PLA Air Force has deployed or has on order around 500 modern fourth-generation fighters and at least two fifth-generation fighters (approximately the equivalent of the F-22 and F-35) under development.


It is ironic that the Army is searching so intensely for a role in an Asian-centric U.S. national security strategy. As demonstrated by the decision to accelerate the planned deployment of a THAAD battery to Guam, the Army could have a major role in regional air and missile defense. Deploying JLENS to Guam would be a good first step and purely defensive. If deployed on the Korean Peninsula, JLENS could provide real-time warning and targeting information on the whole array of North Korean offensive threats from small boats to shorter-range ballistic missiles and very early cueing for the U.S. NMD. Also, JLENs is rapidly deployable and very mobile, which should be highly prized by an Army increasingly concerned about executing strategic maneuvers. The Army needs to invest in JLENS as part of a suite of advanced air and missile defense capabilities.

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