Fact sheet originally posted by SMC.

DOD satellites are controlled in orbit by the Air Force Satellite Control Network (AFSCN), which tracks the satellites, receives and processes telemetry transmitted by them, and sends commands to them. Dedicated control segments support individual satellite systems, but a common user element provides support to all DOD satellites. The common user element consists of two control nodes, two scheduling facilities (one at each node), nine remote tracking sites, and communication links connecting them.

Cstc pixHeadquarters of the Air Force Satellite Control Facility at Sunnyvale AFS, California, in the early to mid-1980s. At the time, this was the only satellite control center operated by the Air Force.

The common user element of the AFSCN was originally activated to support the Discoverer program of the late 1950's and early 1960's. An interim satellite control center was initially established in Palo Alto, California, in January 1959, but by June 1960, a permanent control center had been established in Sunnyvale, California. The installation in Sunnyvale was originally referred to as the Satellite Test Annex, then as Sunnyvale AFS, then as Onizuka AFS, and finally as Onizuka AFB. The control center at Sunnyvale was complemented by tracking stations established at nine different locations between 1959 and 1961. In later years, some of those tracking stations were taken out of service and others were added, and a second control center was added--the Consolidated Space Operations Center (CSOC), located in Falcon AFB, Colorado.

Csoc pixThe Consolidated Space Operations Center (CSOC) at Falcon AFB, Colorado. The CSOC was the second satellite control center activated by the Air Force. It was turned over to Space Command in September 1993.

The Secretary of Defense authorized development of the CSOC in 1979. Originally, it was to consist of two parts--a Satellite Operations Complex (SOC), which would be used for on-orbit control of DOD satellites, and a Shuttle Operations and Planning Center (SOPC), which would be used for the planning and control of DOD missions on the Space Shuttle. However, the SOPC was canceled in 1987, leaving the CSOC with one mission--that of satellite control. The CSOC came on line gradually, starting in 1989. It successfully completed Initial Operational Test and Evaluation in August 1993 and was turned over to Air Force Space Command the following month.

The hardware and software used in the AFSCN has undergone numerous upgrades in the last three decades. One of the most significant upgrades was the Data Systems Modernization program, which introduced new computer hardware and software to perform command and control of orbiting satellites. The program was initiated in 1980, and by February 1992, the new hardware and software was able to perform all functions needed to support the satellites then in orbit. The new system was more reliable than the old one, cheaper to maintain, and faster in its operation, allowing it to support a steadily increasing satellite support workload.

Another significant upgrade was the Automated Remote Tracking Station (ARTS) program, which introduced new, modern equipment at the tracking stations. The contract for Phase I of the ARTS program was awarded in 1984 and the contract for Phase II in 1988. The Phase II contract expired in March 1995, and by that time, ARTS equipment had been installed at all the existing tracking stations and had been used to establish new tracking stations at Colorado Springs and on the island of Diego Garcia. The new equipment offered improved reliability, increased the operational capacity of the tracking stations, and automated many of the functions they performed. Automation and improved reliability reduced the manpower required to operate and maintain the tracking stations and reduced operation and maintenance costs.

Kaena pixThe tracking station at Kaena Point on the island of Oahu, Hawaii.

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