The Northrop Grumman X-47B is a US Navy demonstration unmanned combat air vehicle (UCAV) designed for aircraft carrier deployment, seen here with reporters looking on while on display July 31, 2012 at Naval Air Station Patuxent River, Maryland. The autonomous aircraft has no tail, a maximum unrefueled range of over 2,000 miles (3,200 km), and an endurance of more than six hours. AFP Photo/Paul J. Richards (Photo credit should read PAUL J. RICHARDS/AFP/GettyImages)
