How to talk to a far-away spacecraft: Deep Space Network

1. How to talk to a far-away spacecraft: Deep Space
Network

2. Deep Space Ears: NASA
The largest long-distance listening ear in the World is NASA Deep
Space Network, or DSN. It is in fact not one, but a number of
“ears”, i.e. radio dishes, concentrated in three different locations
around the globe 120 degrees apart in longitude. This way the
instruments in the next location can pick up a signal from a
spacecraft before it disappears from view in the previous location.
The twelve dishes that make up NASA DSN stations are located
in Madrid (Spain), Goldstone (USA) and Canberra (Australia).
Each station has a huge 70 m radio dish as well as several
smaller radio telescopes that can work independently or as an
array. A great website called DSN NOW shows the activity of
each antenna of the Deep Space Network, i.e. what spacecraft it
is talking to, whether an antenna is transmitting or receiving and
more.
Originally, each complex had its own team of operators who
worked in shifts 24 hours a day. But because of the budget cuts,
NASA had to come up with an alternative plan called “Follow the
Sun”. Since 2017 a single DSN complex tracks all spacecrafts in
all three locations during the daytime hours in its part of the
World.

3. Deep Space Ears: ESA
The European Space Agency (ESA) uses NASA DSN to communicate with some of their
spacecrafts. They also have their own Deep Network Stations, the three 35 meter radio telescopes
located in New Norcia, Australia (in operation since 2002), Hebreos, Spain (in operation since
2005) and Malargue, Argentina (in operation since 2012). These stations are operated remotely
from Network Operations Centre in Darmstadt, Germany.
Some other space agencies have their own deep space tracking systems too!
Problems with long-distance space communication
To communicate with the ground, all spacecrafts use frequency bands specially allocated for the
“deep space” conversations. These bands are different from those used for radio astronomy and
for talking to orbiting satellites. Given the high number of ongoing space missions, some of the
frequency bands are already getting very congested. According to the International
Telecommunication Union “the return of science data from deep-space missions is limited by the
capacity of the space-to-Earth links. Often, the amount of science data returned to Earth from a
mission during its lifetime is only a small fraction of what it is capable of producing”. Shocking!
In the nearest future new deep space missions will be launched. Moreover, multiple spacecrafts
are expected to explore the same targets at the same time. This means a vast number of robotic
explorers will be simultaneously sending and receiving a huge amount of data.
The capability of our ground stations will have to grow so that we could keep up the interplanetary
conversation! How will that be achieved? With a bigger network of smaller ground-based dishes?
With some advances in signal processing? We’ll see!

4. Curious about satellites?
•Read the stories of lost-and-found satellites in our blog
post Where is my satellite?
•Learn about NASA mission to study the Solar Corona in
the post Parker Probe: the mission to solve the mystery of
the Sun
•Find out all about the 11 year long mission to the Asteroid
Belt objects Vesta and Ceres in our blog post The last
days of Dawn spacecraft
•Visit our inflatable planetarium or send your questions
and comments to our portable dome team