DARPA’s ISIS program is developing a stratospheric airship with sensor antennas that will include a radar nearly as large as the airship. This would create a battlefield surveillance platform with extreme endurance, and equally extreme resolution for its air and battlefield scans via radar and other carried sensors. This project is associated with Lockheed’s High Altitude Airship program, which is intended to soar at over 65,000 feet for over 30 days at a time, and ISIS could even play a significant role in ballistic missile and cruise missile defense.
Like all DARPA projects, HAA and ISIS pushed the limits of technology, as they work to field a capability set that could revolutionize the US Air Force. If they succeed, these airships could serve as a future substitute for an array of platforms, from UAVs to high-end jets like the E-8 JSTARS and E-3 AWACS. Critical technology areas include low aerial-density advanced airship hull material, bonding systems that will keep the radar attached in a hostile environment, extremely low-power transmit-receive modules for the radars, and novel power systems for long-endurance stratospheric airship operation. HAA has become a US Army program, but ISIS remains with DARPA – for now.