Lockheed Martin has won a $400 million contract to build a high-altitude airship demonstrator featuring radar technology powerful enough to detect a car hidden under a canopy of trees from a distance of more than 300km (160nm).
The Integrated Sensor is Structure (Isis) programme aims to replace several airborne surveillance platforms, including the US Air Force's Boeing E-3 airborne warning and control system and Northrop Grumman E-8C JSTARS airborne ground surveillance aircraft with a fleet of stratosphere-roaming airships.
Selected by the US Defense Advanced Research Projects Agency (DARPA) and the USAF over Northrop, Lockheed's Skunk Works division will build and fly a demonstrator aircraft with a scaled-down sensor system in fiscal year 2013.
This will be equipped with a dual-band UHF radar for tracking ground vehicles or dismounted soldiers, and an X-band radar for spotting small cruise missiles or unmanned air vehicles, DARPA says. The sensors will be significantly smaller than the envisioned operational system, which is expected to occupy an area of 6,000m² (64,600ft2), according to DARPA: equivalent to the size of a 15-storey building.
The planned massive size of the radar aperture would make the sensors more capable than the 375km-range AWACS radar and the JSTARS payload's maximum 300km detection range. An operational aircraft could remain on station for several years, as its solar-powered fuel cells would not require ground refuelling.
"This is an extremely advanced machine that represents a dramatically different approach to persistent real-time intelligence gathering and to the overarching utility of airships," says Lockheed programme manager Eric Hofstatter.
An Isis platform staged in the middle of the Luzon Strait could monitor China and Taiwan across the Taiwan Straits, according to a DARPA briefing chart presented to contractors earlier this year. The airship could reposition itself anywhere in the world within 10 days, it adds.