In the late 1960s and early 1970s DCA, through its NMCS Technical Support Directorate, had responsibility for the technical support, planning, and system engineering for the four command centers then comprising the NMCS. These were the NMCC and the National Emergency Airborne Command Post (these funded by the USAF), the Alternate National Military Command Center (funded by the Army), and the National Emergency Command Post Afloat (funded by the Navy, and deactivated in the late 1960s). DCA performed the requirements collection and analysis, system engineering, funding estimation, subsystem project plan development, and establishment of the initial physical architecture for the expansion of the NMCC that was implemented by the Air Force in the 1970s.