Every satellite has a bus and payload. The bus is the body of the satellite. It carries the payload and is composed of a number of subsystems, like the power supply, antennas, telemetry and tracking command, and mechanical and thermal control subsystems. The bus also provides electrical power, stability, and propulsion for the entire satellite. The payload—carried by the bus—includes all the devices a satellite needs to perform its mission, which differs for every type of satellite. For example, the payload for a weather satellite could include cameras to take pictures of cloud formations, while the payload for a communications satellite may include transponders to relay data such as television or telephone signals. Monitoring and commanding of the satellite payload is done to collect data or provide a capability to the warfighter. Satellite control operations are used to manage the bus and are the focus of this report. Satellite control operations essentially consist of (1) tracking— determining the satellite’s location based on position and range measurements to receive commands from the ground, (2) telemetry— collecting health and status reports which are transmitted from the satellite to the ground, and (3) commanding—transmitting signals from the ground to the satellite to control satellite subsystems. Tracking, telemetry, and commanding (TT&C) are accomplished by a network of ground stations, ground antennas, and communication links between the centers, antennas, and satellites, strategically located around the world. TT&C is essentially the same for any given satellite, based on its orbit, regardless of its mission. Payload control involves operation and control of the payload on the satellite, or managing the operations of a satellite’s mission equipment. The ground segment of satellite control is made up of various ground control centers, ground stations, and user elements. There are two kinds of satellite ground stations: control stations and tracking stations. Satellite control ground stations perform the TT&C functions to ensure that satellites remain in the proper orbit and are performing as designed, and are the stations that manage the bus. The tracking stations enable contact with the satellites through communication uplinks and downlinks. Ground stations can be tied together and can form two types of networks —shared and dedicated. A shared network can support several satellite systems, and is able to share its antennas and software among many different kinds of satellites. While not considering the payload, a shared network is primarily used for bus control and for controlling satellites that are only contacted intermittently using relatively low data rates. However, a shared network can also support functions such as launch and early orbit tracking of satellites, and telemetry and commanding of satellites that are experiencing anomalies. Examples of DOD satellite systems that are controlled by a shared network include the Defense Satellite Communications System and Ultra High Frequency Follow-On system, also a communications satellite. The AFSCN is DOD’s largest shared network. It supports national security (defense and intelligence) satellites during launch and early orbit periods, and is used to analyze anomalies affecting orbiting satellites. It also acts as a backup control system for national security satellites, even for satellites that are not routinely controlled by the AFSCN. AFSCN is comprised of three interrelated segments: (1) operational control centers that provide satellite TT&C support from launch preparation through on- orbit operations, (2) remote tracking stations that provide the space- ground link between satellites on-orbit and the AFSCN, and (3) an interconnected network of space and ground assets with communication links that provides interfaces for external users to access network data. The AFSCN has two operational control centers: a primary center located at Schriever Air Force Base, Colorado; and a secondary control node (backup center) at Vandenberg Air Force Base, California. The AFSCN also has antennas and tracking stations dispersed throughout the world. Figure 1 outlines the AFSCN and related centers, stations, and antennas. The Navy and Army also operate smaller shared satellite control networks with satellite control operations centers, antennas, and tracking stations that support several satellite programs, including: The Naval Satellite Control Network, which operates, manages, and maintains five missions through one operational control center and four remote sites. The Naval Research Laboratory satellite control network, which supports multiple classified and scientific satellite missions through one operational control center. The Army conducts payload control, transmission control, and backup platform control for two missions through five operations centers located throughout the world. In addition to the shared network, the Air Force operates a number of dedicated satellite control networks. A dedicated network operates a single satellite system, and its assets are generally not shared with other satellite systems. Dedicated networks are usually customized or tailored to their associated satellite and therefore unsupportable on the shared networks. In addition, unlike a shared network, a dedicated network often performs both bus and payload control through the same antenna. Examples of Air Force satellite systems controlled by a dedicated network include the Space Based Infrared System (SBIRS), a missile warning satellite system, and the Global Positioning System (GPS), a constellation of satellites that provides positioning, navigation, and timing data to users worldwide. These dedicated networks have 23 antennas at 10 locations around the world. Figure 2 shows the number of antennas at various sites around the world for the AFSCN, a shared network, and for several dedicated networks, such as those used by SBIRS and GPS. Although some satellites using dedicated networks require continuous contact with their ground antennas, thereby precluding those antennas from being shared with other satellite systems, other satellites need only be in contact with their ground antennas on an intermittent basis, thus being potentially compatible with a shared network. Over the past 50 years, and especially in the last decade, DOD has increasingly deployed dedicated satellite control networks in lieu of integrating them into a larger shared satellite control network. DOD is currently operating at least a dozen dedicated satellite control networks, which typically do not share assets or personnel with other dedicated or shared networks, resulting in fragmented and potentially duplicative operations and inefficiencies across its satellite control operations. While dedicated networks offer a handful of advantages to the specific satellite systems they serve, shared networks offer potential advantages DOD- wide in leveraging hardware, software, and personnel. As of February 2013, Air Force officials stated that the Air Force had not worked to move its current dedicated operations to a shared satellite control network, which could better leverage investments. Since 1992, DOD has described its largest shared network, the AFSCN, as among other things, fragmented and lacking standardization and interoperability. In addition, Air Force Space Command officials also stated that consolidation of functions and capabilities, reduction of potential duplication and improvement in interoperability at all levels, is needed. DOD’s share of satellite programs using dedicated networks has increased since 1960, as shown in figure 3. Long-standing systems, such as the Defense Support Program and Defense Satellite Communication System, were developed with their own control centers and antenna sites because existing shared networks could not accommodate them, or because the programs were determined to be better served by combining payload and satellite control operations into a single, dedicated network. As a result of these types of decisions, DOD now uses multiple dedicated networks built specifically for individual satellite programs. Some of these networks include: GPS, which is comprised of two control centers and four antenna sites SBIRS, which is comprised of three control centers and four sites which each have up to five antennas. In recent years, the Air Force has acquired and launched the Space Based Space Surveillance satellite that has its own dedicated system. In addition, plans for other future satellite acquisitions indicate likely additional dedicated networks. While these networks enable satellite control operations, they were not designed to be interoperable. As a result, they require dedicated and unshared control centers and antennas, even when sites are co-located. Figure 4 below illustrates the co-location of several antennas in the Indian and Pacific Oceans operated by the Air Force and Navy (a smaller network), but are not interoperable. Even when control centers are co-located, the configuration of the various networks as well as the organizational structure of the Air Force centers is often fragmented. For example, at Schriever Air Force Base in Colorado, 10 satellite programs are operated by eight separate satellite operations centers under the command of six separate space squadrons, or units, as shown in figure 5. DOD’s reliance on dedicated satellite control operations networks is continuing with its newest satellite system acquisitions, as well as with updates for established systems. Despite being required to conduct a cost analysis and other analyses, DOD officials managing acquisitions of new satellite systems are not required to develop a business case when deciding whether to acquire a dedicated network or to use an existing shared network. Air Force officials stated that in some cases, satellite programs are required to make their dedicated networks compatible with a potential future standard, but many programs receive waivers from that requirement. Furthermore, because dedicated networks effectively meet mission needs, the status quo is upheld without regard for cost or department-wide strategic planning for satellite control operations. New satellites in the early stages of development are already being designed to operate on dedicated networks rather than being designed with the interoperability needed for shared networks. For example, the Precision Tracking Space System, which will be part of the Missile Defense Agency’s Ballistic Missile Defense System, has been designed with a dedicated satellite control operations network. In addition, updates of existing systems, such as the third generation of GPS satellites, are also continuing with the dedicated network approach. Although dedicated networks support the unique needs of some satellite programs, not all satellite control networks need to be dedicated. According to Air Force officials, the increase in dedicated networks reflects more of a preference by satellite program managers than a need. Officials stated that program managers would rather have the large, individual budget for completing its mission, to include a satellite control operations network, and have other programs become compatible with their satellite control operations network, if necessary.