Spying is a sophisticated and expensive business-and gathering military intelligence using unmanned aircraft can be prohibitively so. Predator and Global Hawk, two types of American drone frequently flown in Afghanistan and Iraq, cost around $5,000 and $26,500 an hour respectively to operate. The aircraft themselves cost between $4.5m and $35111 each,rnand the remote-sensing equipment they carry can more than double the price. Which is why less elegant but far cheaper balloons are now being used instead.rnSuch blimps can keep surveillance and ordnance-guiding equipment aloft for a few hundred dollars an hour. They cost hundreds of thousands, not millions, of dollars. And they can stay in the air forrnmore than a week, whereas most drones fly for no more than 30 hours at a time. They are also easy to deploy, because no airfield is needed. A blimp can be stored in the back of a jeep, driven to a suitable location, launched in a couple of hours and winched down again even faster.
展开▼
