SAN DIEGO, Aug. 6 (UPI) -- Northrop Grumman has won a $635.8 million U.S. contract to carry out at-sea carrier launches and recoveries with a fixed-wing unmanned air system. The program will involve Northrop Grumman's X-47B unmanned air system, or UAS, and will be the first set of trials with such a system ever carried out at sea, the company said in a statement Friday. "The Navy's program, known as the Unmanned Combat Air System Carrier Demonstration (UCAS-D), will demonstrate the capability of an autonomous, low-observable air vehicle. The UCAS-D effort will mature critical technologies, reduce unmanned air system carrier...