of Defense. Aerospace has been involved in the analysis of concept designs for the Space Tracking and Surveillance System (SSTS). Aerospace plays an integral role in the development of the Advanced Extremely High Frequency (AEHF) program that will replace the Milstar system. Another system that Aerospace was supporting is the Transformational Satellite Communications System MILSATCOM architecture to link military and reconnaissance communication networks. However, it was canceled per the recommendations of Defense Secretary Robert M. Gates due to DoD budgetary constraints. Aerospace remains a significant partner in the continuing evolution of the GPS system. Aerospace has been playing a leading role in the planning and acquisition of Geostationary Operational Environmental Satellite for the National Oceanic and Atmospheric Administration. In 2005, Aerospace supported the Air Force Affordable Responsive Spacelift (ARES) launch system demonstration program. Capabilities The Aerospace Corporation, as the FFRDC for national security space, primarily supports the Space and Missile Systems Center of the Air Force Space Command, as well as the National Reconnaissance Office. Their 50-year history working side by side with these organizations has made Aerospace the national memory and data repository for launch and satellite systems. They provide scientific and engineering support for launch, space, and related ground systems that serve the national interest. The Department of Defense has identified five core competencies for the Aerospace FFRDC: launch certification, system-of-systems engineering, systems development and acquisition, process implementation, and technology application. Aerospace also manages support to programs for NASA and the National Oceanic and Atmospheric Administration (NOAA), as well as other civil and some commercial space customers. The Aerospace Corporation sponsors several annual conferences and workshops including planetary defense, space systems engineering, space power, and spacecraft thermal control. Organization Space Systems Group The Space Systems Group works with the Air Force, government, and industry partners to develop military satellites and advanced national-security satellite systems. It oversees four major spacecraft and space system areas: communications, surveillance, weather, and navigation. Much emphasis is placed upon the life cycle for systems—as space programs are designed, acquired, and fielded. The Space Systems Group also includes Space Launch Operations which supports Air Force and NRO launch programs by monitoring and collecting data from national security launches. It is responsible for conducting the Aerospace independent launch readiness verification process for legacy and EELV launches. This group focuses on lessons learned, data, and best practices sharing among launch programs. Engineering and Technology Group The Engineering