The latest advance in battlefield intelligence, surveillance, and reconnaissance (ISR) is not the unmanned aerial vehicle (UAV).  No, it’s the use of tethered aerostats as a platform for cameras, radars, and other surveillance equipment that monitor wide areas around important locations. In contrast to a blimp, which is a lighter-than-air powered vehicle, an aerostat has no ability to move under its own power and is tethered to the ground at a single location. Blimps (or dirigibles or zeppelins) were used on the battlefield in World War I, and aerostats were used in World War II as defenses against aerial assault, but such craft have rarely been seen on a battlefield since that time—until recently, when the US Military deployed them in Southwest Asia to enhance ISR systems. According to this story, something floating in the sky over Kandahar is “making the locals uneasy.” The article continues, “’Many people believe it's a spy blimp that can see through walls to look at our women,’ said [one Kandahar local] ‘People don't like it … some are saying they are going to shoot at it.’” The Afghan local is correct:  it is a spy blimp—or, more accurately, an aerostat.  And it’s not alone.  It’s part of the RAID ISR system.

Since 2003, the Rapid Aerostat Initial Deployment (RAID) program has deployed more than 60 airborne systems (as well as 300 RAID towers) in Afghanistan, protecting Forward Operating Bases (FOBs) and other critical locations as part of the US’ “persistent surveillance and dissemination system” (PSDS), used primarily by the Army and Marine Corps. The RAID system utilizes a 50-foot long aerostat carrying a 200 pound payload at heights of 1,000 feet.  According to this article at Defense-Update.com:

RAID generally utilizes EO/IR sensors, radars, flash and acoustic gunshot detectors, to provide persistent, panoramic surveillance of the covered area, [that provide] timely warning of potential threats and other events …. The main sensor is an EO/IR payload, carrying a laser rangefinder, designator and target marker. In some configurations, radar, RF signal interceptors or gunshot detectors are employed, providing a primary scanning sensor pointing the EO/IR payload to points of interest, where movement or suspicious actions are detected. Other sensors can cue the RAID as well, including counter mortar radars such as the LCMR, which detects mortar attacks and can cue the RAID in seconds.

RAID sensor data is fed through standard radio links (SINCGARS and EPLRS) to the RAID ground control system, also known as Persistent Surveillance and Dissemination System (PSDS2) and Enhanced Tactical Automated Security System (eTASS). RAID systems provide essential situational awareness necessary for improved security and daily operations in and around the FOB. For example, convoy leaders check with RAID operators for 'road clear' indication before leaving the FOB.

Modern use of aerostats in the battlefield goes back at least 20 years to the early 1980’s, when (according to this report by the Congressional Research Service or CRS), “the Tethered Aerostat Radar System (TARS) [began] operating … at eight sites along the southern U.S. border and in the Caribbean. Currently, TARS’ primary mission is surveillance for drug interdiction.  Each aerostat can lift 2,200 lbs of radar or other sensors to a height of 12,000 feet, and can detect targets out to 230 miles. The aerostat can stay aloft for months at a time.”

Another aerostat program called JLENS is an Army-led joint program that “seeks to use advanced sensor and networking technologies to conduct cruise missile defense.” According to the CRS report, “JLENS is seen by some to be an important test case for DOD’s network centric warfare approaches, because it is the centerpiece of a larger attempt to seamlessly link together numerous sensors across services to build a “single integrated air picture,” that will enable effective cruise missile defense.” (Emphasis in original.)

The High Altitude Airship or HAA is a Missile Defense Agency-funded Advanced Concept Technology Demonstration project focused on homeland defense.  The CRS report states that “The HAA would operate at very high altitudes, up to 70,000 ft, and has been likened to a low flying, and relatively inexpensive satellite.  This altitude might enable a small number of airships to surveill the entire United States.”

CRS also reports that “Since 1999, the Navy has explored a return to airships via the Littoral Airborne Sensor Hyperspectral (LASH) airship program. The LASH airship might be used for existing Navy missions such as anti-submarine warfare, search and rescue, detecting chemical and biological weapons attacks, or mine countermeasures operations. Domestic agencies such as the Coast Guard may also be interested in LASH for antiterrorism and border security roles.”

On October 7, 2009 Lockheed Martin received a $133 million contract award for eight additional Persistent Threat Detection Systems (PTDS) to be added to the nine already deployed in theater.  A PTDS aerostat is smaller than a TARS craft, according to an article at www.defenseindustrydaily.com.  It is “115 feet long with 74,000 cubic feet of helium and a 1,102 pound payload.”

Meanwhile, Lockheed Martin proceeds with development of the Long-Endurance Multi-Intelligence Vehicle (LEMV) in anticipation of a future contract award.  Based on its existing P-791 design, the LEMV will be a 250 foot-long blimp (i.e., able to move under its own power) and will be designed to loiter at 20,000ft for up to 21 days carrying a 2,500lb ISR payload. The contract will require deployment within 18 months of award.

According to the linked AviationWeek.com article:

The LEMV is a hybrid airship - it's heavier than air, 80% of its lift coming from buoyancy and 20% from aerodynamics. Propulsion comes from six thrusters - three per side - powered by individual turbo-diesels for take-off and climb, and electrically from a central turbo-generator for loiter. And it's non-rigid, structural stability results from the three-lobe envelope design. The airship is also optionally piloted - flown manned for self-deployment and unmanned for persistent ISR missions.

An air cushion landing system allows the airship to be maneuvered for taxiing and take off, and sucks the vehicle down on to the ground - or sea surface - for landing, loading and unloading.

Hanging under the envelope, behind the sometimes-occupied cockpit, is a payload bay 40ft long, 15ft wide and 6-8ft tall - more than enough room to mount either a ground moving-target indication radar or multi-camera wide-area motion imagery sensor, plus a signals-intelligence payload and multiple EO/IR sensors.

It seems ironic that the latest ISR advance may harken back to century-old military technology.  But sometimes old school is the way to go. (Though hopefully some lessons have been learned since then …)