Once known as Raytheon Intelligence and Space, and also as Raytheon Space and Airborne Systems, this building, with a footprint of a million square feet, is part of Raytheon Technologies, now simply called RTX, as the company renamed itself in 2023, after its latest merger (with United Technologies). Raytheon is one of the top three defense contractors in the USA, and this facility is its largest development site for systems involving space-based sensors (satellites), command and control, radar, intelligence, and electronic warfare. The company is well-known for its Patriot Missile System and other missile and missile defense systems. This facility was previously owned by Hughes Electronics, which Raytheon bought in 1997. Founded in Waltham, Massachusetts, Raytheon’s headquarters recently moved to Arlington, Virginia. Raytheon has more than 6,000 employees in El Segundo, and most of them work in this building.