Secretary of Defense Robert Gates announced Wednesday that Northrop Grumman and Boeing will have to submit revised proposals for the Air Force’s highly contested aerial refueling tanker program. The Pentagon chief's decision comes after the Government Accountability Office (GAO) upheld Boeing's protest of the Air Force's decision to award the contract to Northrop Grumman and EADS North America, the parent company of Boeing rival Airbus. “I have concluded that the contract cannot be awarded,” Gates said at a Pentagon news conference. Northrop Grumman won the heated competition on Feb. 29, but is currently under a stop-work order. The decision means...