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8.1.2 Tracking Stations

Telemetry data from NASA-supported spacecraft are received by a worldwide network of tracking stations called the Spaceflight Tracking and Data Network (STDN). The northernmost station is located in Fairbanks, Alaska, at 65° North latitude; the southernmost is in Orroral Valley, Australia, at 35° South latitude. The locations of fixed STDN stations are given in Fig. 8-4 and detailed locations are listed in Table 8-3. In the second column of this table, the abbreviations USB and GRARR indicate unified S-band and Ground Range and Range Rate, respec-

Fig. 8-4. Locations of STDN Stations. (The three-letter station designators are defined in Table 8-3.)

tively. In addition to the permanent tracking stations, the network includes portable land-based stations (vans), a ship (the USNS Vanguard), and several specially equipped Advanced Range Instrumented Aircraft (ARIA). Figures 8-5 through 8-8 show examples of STDN facilities. This network of receiving stations supports NASA's Earth-orbiting scientific and applications satellites, interplanetary missions, and manned space flight.*

One of the larger STDN stations is located at Rosman, North Carolina, and is shown in Figs. 8-8(a) to 8-8(d). The aerial view in Fig. 8-8(a) shows seven of the station's tracking and data acquisition antennas. The largest ones are two 26-m telemetry antennas at either end of the large clearing just above the center of the photograph. (Closeups are shown in Figs. 8-5 and 8-8(b)). In the clearing above and to the left of the large antenna in the center are two Satellite Automatic Tracking Antennas (SATAN). The two antennas in the clearing in the lower left corner of the aerial view are range and range-rate antennas and are shown in Fig. 8-8(d). Finally, the VHF Satellite Command Antenna on Medium Pedestal (SCAMP) antenna of Fig. 8-8(c) is in a small foreground clearing along the righthand edge of the aerial view.

Operational control and scheduling of the network is provided by the Network Operations Control Center (NOCC) located at Goddard Space Flight Center (GSFC)

•The Jet Propulsion Laboratory (JPL) Deep Space Network (DSN) handles communications for interplanetary missions. Because of the long distances involved, this system uses the 26-m antennas in Madrid, Spain, and Goldstone, California.

Table 8-3. Geodetic Coordinates of STDN Stations Tracking System, Referenced to Fisher '60' Ellipsoid, Semimajor Axis=6378166 m and I /flattening=298J. (See Appendix L for the transformation to geocentric coordinates.) System locations are subject to minor changes as refinements in positional accuracies are made.

Table 8-3. Geodetic Coordinates of STDN Stations Tracking System, Referenced to Fisher '60' Ellipsoid, Semimajor Axis=6378166 m and I /flattening=298J. (See Appendix L for the transformation to geocentric coordinates.) System locations are subject to minor changes as refinements in positional accuracies are made.

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