(Editor's Note: This story was updated on March 27 to clarify the B-21 and GBSD digital design tools are Northrop Grumman products.) Northrop Grumman and Raytheon are proposing a Next Generation Interceptor that features "sixth-generation" kill vehicle technology and adapts state-of-the-art digital tools from B-21 bomber and Ground Based Strategic Deterrent programs, according to company representatives. On March 23, the Missile Defense Agency selected Northrop and Raytheon to compete against Lockheed Martin for the NGI initial design phase, the...