The United States Army has ordered a huge hybrid airship longer than a football field to watch over battlefields in Afghanistan by the end of 2011, according to the airship's builder Northrop Grumman Corporation. The company has received a $517 million Army contract to build up to three of the huge military airships, called the Long Endurance Multi-Intelligence Vehicles (LEMV). Such airships would serve as surveillance stations at 20,000 feet (6,096 meters) above sea level and could stay on watch for as long as three weeks at a time. A LEMV would also have the capability to carry a 2,500-pound...