Every U.S. deep space mission is designed to allow continuous radio communication with the spacecraft. The locations in Spain, Australia, and California are approximately 120 degrees apart in longitude, which enables continuous observation and suitable overlap for transferring the spacecraft radio link from one complex to the next. Each complex consists of at least four deep space stations equipped with ultrasensitive receiving systems and large parabolic dish antennas. One 34-meter Beam Waveguide antenna. One 11-meter antenna.
New antennas are under construction.
The ability to array several antennas was installed to improve the data returned from the Galileo spacecraft. The California and Australia sites concurrently pick up communications with Galileo. All the stations are remotely operated from a centralized Signal Processing Center at each complex. The Centers house the electronic subsystems that point and control the antennas, receive and process the telemetry data, transmit commands, and generate the spacecraft navigation data. Once the data is processed at the complexes, it is transmitted to JPL for further processing and distribution to science teams over a modern ground communications network .