We use the DSN ([Deep Space Network](https://www.jpl.nasa.gov/missions/dsn)) to communicate with the observatory. We receive data when we have a contact with Webb using a DSN antenna
The DSN has three sites around the world, each positioned 120 degrees apart. There are antennas in Goldstone, California; Canberra, Australia; and Madrid, Spain. This allows us to communicate with Webb at any time of day
Each of the [DSN complexes](https://www.nasa.gov/directorates/heo/scan/services/networks/deep_space_network/complexes) has different types of antennas, including 70-meter (230-foot in diameter), 34-meter (111-foot in diameter), and 26-meter (85-foot in diameter) antennas. The DSN complexes use the 34-meter antennas to talk with Webb with the 70-meter antennas as a backup.
The DSN supports different radio frequency allocations, such as the S-band and Ka-band frequencies that Webb uses.
-band has a lower bandwidth, and we use that to send commands to the spacecraft (e.g., start recorder playback), to receive engineering telemetry to monitor the health and safety of the observatory, and for ranging. Ranging is the process of determining Webb’s position and trajectory by the delay between when the signal is sent up and when it is received back on the ground
We use Ka-band to downlink stored science and engineering data, and some telemetry from the spacecraft.