Orbital ATK Up 20% On News Of Northrop Grumman Deal By: Benzinga via Benzinga September 18, 2017 at 08:22 AM EDT Defense giant Northrop Grumman Corporation (NYSE: NOC) confirmed Monday it will buy Orbital ATK Inc (NYSE: OA), the maker of the Pegasus ... Read More >> Related Stocks: Bio-Techne Corp Northrop Grumman Orbital ATK, Inc. Common Stock Rockwell Collins United Technologies