An undated U.S. Air Force handout photo of a RQ-4 Global Hawk unmanned aircraft

 
An undated U.S. Air Force handout photo of a RQ-4 Global Hawk unmanned aircraft
An undated U.S. Air Force handout photo of a RQ-4 Global Hawk unmanned aircraft.REUTERS/U.S. Air Force/Bobbi Zapka/Handout