Bob Simon reports on Israel’s “Iron Dome,” a game-changing defense system that the Israeli Air Force says shot down 85 percent of the rockets its enemies fired into the country from nearby Gaza last November. The world’s largest civilian hospital ship takes volunteer medical staff to the Third World where they have restored sight to thousands of people suffering from cataracts and returned smiles to victims of facial tumors and cleft palates. Scott Pelley reports. Steve Kroft profiles Downton Abbey’s Maggie Smith, who, at 78, has reached new heights of stardom due to the popular PBS series.