U.S. Army considers blimps as anti-missile defense

An airship that the U.S. Army says is the largest lighter-than-air vehicle ever used in U.S. military operations will make its debut flight in August as part of an effort to field a system to detect, track, and shoot down cruise missiles, FOX News reports.

Unlike ballistic missiles that typically fly a stable and predictable flight pattern, cruise missiles pose a particularly tough challenge because of their ability to fly low and slow and change directions. The weapon systems now available for cruise missile defense, such as the Patriot and Terminal High Altitude Area Defense systems, rely on ground-based tracking radars that cannot see over the horizon and can be negated by ground obstacles such as mountains.

The Air Force flies radar-equipped airplanes that can track cruise missiles from above, but these systems require a lot of manpower and other resources to operate.

This led the Army to begin looking at the potential for radar-equipped aerostats — tethered balloons resembling blimps — to detect and track terrain-hugging cruise missiles. After a series of demonstrations to prove the concept, the Army in December 2004 launched a program called the Joint Land Attack Cruise Missile Defense Elevated Netted Sensor System (JLENS) with the award of a $1.4 billion development contract to Raytheon Integrated Defense Systems of Tewksbury, Massachusetts

Raytheon is working to deliver two JLENS systems, each consisting of two 242-foot (74-meter) long helium-filled aerostats, a surveillance radar, a fire control radar, mobile mooring stations and communications packages. One of the aerostats hosts a surveillance radar, which provides 360 degree coverage, and the other carries a fire control radar, which receives the surveillance data and generates targeting data for Army weapon systems.

The aerostats will operate nearly 2 miles (3 km) above the ground on tethers, providing the ability to detect and track cruise missiles as far as 124 miles (200 km) away in every direction, Army Lt. Col. Steve Willhelm, the JLENS program manager, said in an interview. The systems are designed to operate continuously for thirty days, come down for eight hours of maintenance and go back up for another thirty days.

The program in December completed its critical design review and is in the fabrication and integration phase. TCOM of Columbia, Maryland, is building the aerostats, the first of which will make its first flight in August up to about 2,952 feet (900 meters) above the ground at the company’s Elizabeth City, North Carolina, manufacturing facility,