Real Life Space Communications

As we all know, a lot of science fiction involves space travel. We sometimes tend to forget that real life space travel already takes place, albeit on a somewhat limited scale.

This week end I did a little listening to spacecrafts on the radio. You may not believe it, but space communications is not as difficult as many people would think.

I was finding out when the ISS came over the horizon here and started listening to a relay station for ham (amateur) radio situated on the ISS. If there is not any spacewalks going on, the relay station is active listening on the 435MHz (uplink) band (70cm) and transmitting on the 145MHz (downlink) band (2m).
The downlink on 145.800MHz was clearly audible with a scanner radio and a simple whip antenna, as soon as I went out on the balcony of my apartment. On average the period with audible signals is 10 minutes per pass, shorter when the pass is near the horizon and longer when the station comes over my head.

Many years ago I sometimes set my receiver to 143.625MHz in order to listen for the MIR space station (yes - the Russian one), and have heard that one talking to the Earth station.

On some occasions it is possible to have a contact with one of the astronauts on the ISS, if they have the free time and interest. Almost all the astronauts have the license to transmit from up there.

In fact, the radio hams have several satellite relays orbiting the Earth, giving them the opportunity to try out space communications. Most of those are in a low Earth orbit, and therefore they are only useable for a short time. Some have a very elongated orbit (not really any right now), giving the opportunity for longer communication periods.

Most of us know about TV and communications satellites in the geostationary orbit (the satellite follows the Earth's rotation and seems to be stationary over a certain point on the Earth). The dream of some radio hams is getting their satellite out there, giving 24/7 communications.

Just a dream ... but maybe not any longer. There seems to be negociations going on between the AMSAT (Amateur Satellite) organisation and Inmarsat, about getting a lift with one of their satellites, and even sharing the power from the solar panels. We never know if this will come true, but I sure hope so.

Do not forget that the Space Station is a rather big satellite and is very easy to see when above the horizon. So - even if you cannot receive it on the radio you can go outside and observe a *real life* manned spacecraft. if you want to know when it can be observed at your place , go to Heavens Above and find out. it is a good idea to register, so you can have your location recognised when you log on.