Air Force Satellite Control Network

The Air Force Satellite Control Network (AFSCN) provides support for the operation, control, and maintenance of a variety of United States Department of Defense and some non-DoD satellites. This involves continual execution of Telemetry, Tracking, and Commanding (TT&C) operations. In addition, the AFSCN provides prelaunch checkout and simulation, launch support, and early orbit support while satellites are in initial or transfer orbits and require maneuvering to their final orbit. The AFSCN provides tracking data to help maintain the catalog of space objects and distributes various data such as satellite ephemeris, almanacs, and other information. The AFSCN consists of satellite control centers, tracking stations, and test facilities located around the world. Satellite Operations Centers (SOCs) are located at Schriever Air Force Base near Colorado Springs, Colorado, and various other locations throughout the continental United States. These SOCs are manned around the clock and are responsible for the command and control of their assigned satellite systems. The SOCs are linked to remote tracking stations (RTSs) around the world. Space vehicle checkout facilities are used to test launch vehicles and satellite platforms to ensure that the onboard systems operate within specifications. The RTSs provide the link between the satellites and the SOCs. A similar relationship exists for dedicated networks, which are outside the purview of the AFSCN. RTSs around the world are needed to maintain frequent communications with the satellite. Without RTSs, the SOCs would only be able to contact a satellite when it came into the control center's view. Some satellites, especially those in geostationary orbit, never come within view of their control center. Each antenna at an RTS is referred to as a 'side'. Previously, Side A typically included a 60-foot-diameter (18 m) dish antenna. Side B typically included a 46-foot-diameter (14 m) antenna. At some sites, the B side included a 33-foot-diameter (10 m) antenna. Over time, however, as the network upgraded and/or replaced the antennas, the old conventions no longer apply. AFSCN was originally activated to support the CORONA (Discoverer) program in 1959. An interim satellite control center was initially established in Palo Alto, California, and by June 1960, a permanent control center had been established Sunnyvale AFS, later renamed Onizuka AFS, Sunnyvale, California. The main operations control center, now at Schriever Air Force Base, Colorado Springs, CO, functions as a central command and control node for the remote tracking stations established at several different locations. The AFSCN maintains a number of tracking stations, which are used to track (primarily) US government agency & military satellites, as well as receive and process telemetry and send commands to these satellites. Said facilities are intended to support all Department of Defense satellites. Most tracking stations are operated by operational detachments of the 21st Space Operations Squadron (21 SOPS) and 23d Space Operations Squadron. Many scientific and research satellites are supported as well.