Northrop Grumman Corp. will do upgrades to the B-2 stealth bomber at its Palmdale manufacturing facility under a contract with the U.S. Air Force. Modernizing the aircraft’s defensive management system, which includes antennas and display processors, will take about three years. Lockheed Martin Mission Systems and Training, L3 Randtron, and Ball Aerospaceare suppliers of technology for the upgrades. The aircraft will be modernized through the installation of the latest existing technologies, said Lauren Stevens, director of the company’s B-2 modernization integrated product team. “Instead of relying on new hardware and software development, our initiative takes advantage of mature, proven technologies,” Stevens said in a prepared statement. “It minimizes nonrecurring costs, and reduces the time and technology risks associated with fielding new capabilities.” The B-2 has a range of 6,000 nautical miles unrefueled and more than 10,000 nautical miles with just one aerial refueling, giving it the ability to reach any point on the globe within hours.