The first use of aerial vehicles on the battlefield was balloons hoisted up into the to spy on enemy troop movements, and occasionally to drop bombs. Balloons were used in the American Civil War, and even during the French Revolution, though in recent decades emphasis has shifted towards jets, rather than balloons.
But that may be about to change. The U.S. Air Force is looking into a high-flying, solar-powered blimp to take over spy duties, and say a small demonstration prototype could be in the air by 2014.
The idea behind the ISIS is to offer more information at less cost. Spy planes require lots of logistics support such as fuel, ground bases, and of course extensively-trained pilots. The ISIS needs none of that. You could park it over a spot and let it observe for 24 hours a day, seven days a week, never missing a single thing thanks to its high-tech cameras and radar.
During the day, power for all this technology comes from top-mounted solar cells, which create hydrogen and oxygen from water, which is then recombined in a fuel cell for energy during the night. The ISIS uses low-power “cell phone technology” to keep the weight and complications down. Sounds pretty cool, and there should be a working model around 2014. Just don’t expect to be flying on a solar blimp anytime soon.