Communications System

How does NASA communicate with spacecraft?

What is DSN?

The NASA Deep Space Network - or DSN - is an international network of huge antennas that allows people on the ground to communicate with satellites and other spacecraft missions, as well as providing radio and radar astronomy observations for the exploration of the solar system and the universe.

A radio telescope at Goldstone. Notice how small the cars are compared to the dish. Photo Courtesy of Jet Propulsion Laboratory Goldstone Radar web site,

The DSN currently consists of three deep-space communications facilities placed approximately 120 degrees (or one third the way around the world) apart: at Goldstone, in California's Mojave Desert; near Madrid, Spain; and near Canberra, Australia. This strategic placement permits constant observation of spacecraft as the Earth rotates, and helps to make the DSN the largest and most sensitive scientific telecommunications system in the world.

Spacing the DSN stations 120 degrees apart ensures that there is always a station that can send and receive signals facing any point in space at any time, so that as a spacecraft moves, we can track it.

The 120 degree spacing also ensures that we can track a satellite that stays in place as the Earth turns.

NASA's scientific investigation of the Solar System is being accomplished mainly through the use of unmanned automated spacecraft. The DSN provides the vital two-way communications link that guides and controls these spacecraft, and collects the images and scientific information sent by them.

Among other things, the DSN makes it possible to:

How much time on the Deep Space Network is DS1 getting?
What are uplink and downlink?
How long does it take for transmissions to get between DS1 and Earth?
How often is DS1 in communication with Earth?
What is a satellite?

What kind of data is DS1 sending back?
Why does communication get harder at greater distances?
How much data is DS1 able to transfer?

How is data processing managed?
What is the Doppler effect?