Brief Description of the Deep Space Network
The Deep Space Network (DSN) is an international network of antennas that supports interplanetary spacecraft missions, selected Earth-orbiting missions, and radio and radar astronomy observations for the exploration of the solar system and the universe. The network is a NASA facility managed by the Interplanetary Network Directorate (IND) within the Jet Propulsion Laboratory (JPL). (See Figure 3.2.1.)
The origins of the DSN can be traced back to the late 1950s and the inception of NASA in 1958. The execution of several planetary robotic missions, managed by JPL, also contributed to the further development of the network, which expanded from a single tracking station to a worldwide network of large-dish antennas.
The DSN consists of three deep space communications facilities strategically placed approximately 120 degrees from one another. The Goldstone Deep Space Communications Complex is located in California’s Mojave Desert; the Madrid Deep Space Communications Complex is in Spain, 37 miles to the west of Madrid at Robledo de Chavela; and the Canberra Deep Space Communications Complex is in the Australian Capital Territory, 25 miles southwest of Canberra near the Tidbinbilla Nature Reserve.
Each complex is situated in semimountainous, bowl-shaped terrain for better shielding against radio-frequency interference, and consists of at least four deep space stations equipped with ultrasensitive receiving systems and large parabolic dish antennas. The system is made up of the following array of antennas: one 34-meter-diameter high-efficiency antenna, one or more 34-meter beam waveguide antennas (three at Goldstone, two in Madrid, and one in Canberra), one 26-meter antenna, and one 70-meter antenna. Every one of these is a steerable, high-gain, parabolic reflector antenna.
FIGURE 3.2.1 One of the 70-meter dishes of the Deep Space Network. This system currently has long-term maintenance and usage challenges, but it would be significantly taxed by many of the proposed mission concepts evaluated in this study. SOURCE: Courtesy of NASA.
All of the stations are remotely operated from a centralized Signal Processing Center at each complex, which house the electronic subsystems that control the antennas, receive and process the data, transmit commands, and generate the spacecraft navigation data. The data are then transmitted to JPL for further processing and distribution to science teams over a ground communications network.
The antennas and data delivery systems make it possible to acquire telemetry data and transmit commands to spacecraft, track spacecraft position and velocity, perform very long baseline interferometry observations, measure variations in radio waves for radio science experiments, gather science data, and monitor and control the performance of the network.
The strategic placement of these facilities is what characterizes the DSN as the largest and most sensitive scientific telecommunications system in the world. Their position permits the constant observation of spacecraft and enables continuous observation and suitable overlap for transferring the spacecraft radio link from one complex to the next.