Boeing Integrated Defense Systems is a unit of The Boeing Company responsible for defense and aerospace products and services. Integrated Defense Systems was formed in 2002 by combining the former "Military Aircraft and Missile Systems" and "Space and Communications" divisions. Integrated Defense Systems makes Boeing the second-largest defense contractor in the world and is responsible for 56% of the company's income. Boeing IDS is based in Berkeley, Missouri, USA, near the city of St. Louis. Boeing is the largest employer in St. Louis County. Integrated Defense Systems is a consolidated group which brought together major names in aerospace; Boeing Military Airplane Company; Hughes Satellite Systems; Hughes Helicopters minus the commercial helicopter products; Piasecki Helicopter, subsequently known as Boeing Vertol and then Boeing Helicopters; the St. Louis-based McDonnell division of the former McDonnell Douglas Company; and the former North American Aviation division of Rockwell International.