In the Spotlight: NASA Deep Space Network
The last two weeks have seen a lot of traffic out there in space. NASA needed to keep up the communication with DART as well as Juno, besides of course talking with different Mars rovers and even the voyagers out there in deep space. So how does NASA do that?
Deep Space communication is crucial when communicating with space crafts millions of kilometers away from home. As an example, there are several rovers on Mars, which are in constant communication with NASA. Mars is 112.81 million km away, which means that the signal travels around 6 minutes each direction.
The numbers become even more insane when you take a look at Voyager 1, which is 23.661.904.392 km away from home. For a signal to travel that far, as we know wave signals travel with lightspeed, the communication delay before we can get an answer is 42 hours.
Last example the Jupiter moon Europa, where the spacecraft Juno just completed a close flyby, is 628.3 million km away, so one way communication is around 34 minutes.
The speed of light is approximately 300.000 km per second, so we can use the following to calculate the travel time in seconds.
distance km / 300.000 km/s
As we send out a signal, we of course expect an answer back, with delay you can imagine that the antenna sending the signal is not at the same position it has been before, well not even earth is at the same position.
So how do we still get to receive the answer? We simply place powerful antennas across the earth.
NASA’s Deep Space Network is a cluster of antennas which are located at three different locations.
- Barstow California (USA)
- Madrid , Spain
- Canberra, Australia
Each complex around the world shares the almost identical setup of
- 3 or more 34 meter Beam Waveguide Antennas (BVA)
- One 70 meter antenna
The stations need to operate on 4 different bands, S, X, K and Ka. Those bands have been allocated by the International Telecommunication Union (ITU).
The 70m dishes deliver a gain of between 61.04 dBi (L Band) and up to 80.2 dBi (K Band). After all signals have been collected via their antennas and are down converted, the data will become analog data and distributed via fiber.
All data and current communication can be viewed via a live stream.
More technical details can be found here in the pdf
In the next Spotlight we will take a closer look at ESTRACK, The European communication array.
This news item was first published on “Space and Ham Radio News” a Newsletter published every Sunday on Patreon. If you want to be among the first to read please become a supporter