Northrop Grumman Corp. engages in the provision of advanced aircraft systems. The company is headquartered in Falls Church, Virginia and currently employs 101,000 full-time employees. The firm operates through four segments: Aeronautics Systems, Defense Systems, Mission Systems and Space Systems. The Aeronautics Systems segment is engaged in the design, development, production, integration, sustainment and modernization of advanced aircraft systems for the United States Air Force, the United States Navy, and international customers. The Defense Systems segment is engaged in the design, development, production, integration, and production of advanced tactical weapons and missile defense solutions, and a provider of sustainment, modernization and training services for manned and unmanned aircraft and electronics systems. The Mission Systems segment is engaged in advanced mission solutions and multifunction systems. The Space Systems segment is engaged in the design, development, integration, production and operation of space, missile defense, launch and strategic missile systems.