SIERRA VISTA — The aerostat that floats above Fort Huachuca will continue to monitor the U.S./Mexico border, at least through September, 2013, U.S. Rep. Ron Barber announced Tuesday. The Tethered Aerostat Radar Systems, or TARS, was scheduled to discontinue March 15, following an announcement by the U.S. Air Force in January. Barber was among 15 members of Congress who responded to that announcement, signing onto a letter that was sent to the heads of the Department of Homeland Security, the Department of Defense and deputy director for management at the Office of Management and Budget. Tuesday, Barber’s Washington, D.C. office...