A Northrop Grumman RQ-4 Global Hawk Block 40 remotely piloted aircraft in flight. The Block 40 is one of three variants of the high-flying, long-endurance Global Hawk that the Air Force currently operates. This version is designed to carry the Northrop Grumman-Raytheon MP-RTIP advanced electronically scanned array radar for synthetic aperture radar imaging and tracking moving ground targets. ; posted on Jan. 7, 2013, at the company's website.