The Future Of Airborne ISR May Really Be Hot Air

The great revolution to emerge from the Iraq and Afghanistan conflicts is airborne ISR. From having literally only a handful of manned and unmanned aerial ISR sensors at the start of these conflicts, the U.S. military now has almost ten thousand deployed. They range in size and capability from the hand-launched Wasp and Raven through the small Scan Eagle to the medium size Shadow, Predator and Global Hawk unmanned aerial vehicles (UAVs) and new manned systems such as the MC-12W Liberty. Not only have the number and variety of platforms exploded but there has been a revolution in sensor systems and the ability to deliver information, including real-time streaming video down to the lowest tactical levels. New sensor systems about to be deployed such as Gorgon Stare will allow a single ISR platform to track dozens of moving targets simultaneously.

The future of airborne ISR may really be a lot of hot air. The first generation of a new type of unmanned platform is already being deployed. These new platforms are balloons, or more accurately aerostats. An aerostat is a tethered blimp that is filled with helium so it is lighter-than-air. Think of the old World War II barrage balloons. Except these are smart balloons with a sensor suite that can include electro-optical and infrared cameras, radar, sound and flash detectors and laser rangefinders/target designators. In addition, the ground control and intelligence center for each aerostat uses advanced computer software to do automated target recognition. The average aerostat carries a 200-500 pound payload and operates at between 1,000 and 2,500 feet. At the latter height it can find targets out to a distance of 200 kilometers. If unmolested, the aerostat can stay aloft for days.

There are over thirty of these already deployed in Afghanistan under the Rapid Aerostat Initial Development program and the Pentagon wants to double that number. The aerostat system is complemented by similar sensor suites deployed on high towers. In flat, open terrain such as most of Iraq and southern Afghanistan, towers can be good enough to protect a base from surprise attack, even from indirect fire weapons such as mortars. But in complex terrain such as cities and mountains, an aerial surveillance platform is needed to look over blocking terrain features. Also, an aerostat is a lot less expensive than a persistent UAV. But unlike a UAV, it cannot move rapidly to where it is needed, follow a moving target or provide continuous coverage of moving friendly forces. So both types of platforms have a place in the U.S. arsenal of airborne ISR systems.

The role of aerostats is not limited simply to war zones such as Afghanistan. The U.S. Air Force has deployed a number of such systems for years along the southern border to detect drug smugglers. Aerostats equipped with radar have also been investigated as part of a U.S. homeland defense against low flying land-attack cruise missiles. The Marine Corps is looking to deploy aerostats to function as high-altitude communications relays.

Aerostats are but the first generation of what is likely to be an ongoing revolution in “hot air” platforms. The next step is something called a High Altitude Airship (HAA). The HAA is more like the old zeppelin of the first part of the last century, except with the addition of modern technologies and aerodynamic design. The Army has let a contract to Northrop Grumman to build three Long-Endurance, Multi-Intelligence Vehicles (LEMV). The LEMV is a nonrigid airship filled with helium, but it will not be lighter- than-air. Rather, it will use a combination of lift from its aerodynamic shape and the forward momentum from its four vectored-thrust ducted propellers to help it get and remain airborne. A LEMV will have about 3-week endurance, fly at 20,000 feet, carry 2500 pounds of payload, and travel at speeds between 30-80 knots. It can be equipped with a wide variety of sensors, some much larger than what can be lifted by the smaller aerostats.

There are even plans for extremely large HAAs that can serve as a commercial carrier. Future HAAs could carry multi-ton cargoes around the world without the need to land at an airfield. An HAA would be slower than a commercial aircraft but much faster than a container vessel. The military could use it to help deploy and resupply forces in the field. But commercial logistics providers could use them to carry a wide variety of cargoes.