How is space communication done?

How is that we are able to receive the waves transmitted from saturn to earth in 45 minutes with accuracy..How are scientists modelling the atmosphere of the "space"?? How is modelling of cosmic radiation done??

Wow, this though..
Well I can see them makin it in perfect accuracy.. but we got satellite in the sky and out side the earth atmosphere...

Well free space is a good conductor and the satelite we have will take the parameter such the density, temp and all more at the area. Well they can calculate according to the equation and by simulation..

Well they claimed it to be accurate... who know unless we arrive at saturn?

Concerning long-distance space communications, the trick is in very low data rates, something like few bits per second.
The idea is very similar to spread-spectrum communications. Transmission of one bit takes place on rather high frequency for rather long time. When many waves that make the bit are summed up at earth, the received signal power increases but noise cancels out.

Yet another way to receive weak signals is to use sinchronised antennas that are placed in large area, like 50 km or more accross. Summing signal over many antennas increases received power. Such antennas are used for deep-space exploration, because of having high directivity.

I can't tell you anything on space modelling. That is is a subject of astrophysics, rather than communications.

Is it not the fact that Space is near vacuum? So everything travels at the speed of light? Now in case if we have a spread spectrum model working there, would it not be near perfect transmission without any scattering?