If you are really serious re space etc, there are several amateur radio satellites that can be listened to relatively easily, an antenna such as a yagi or if really keen a high gain antenna such as a dish (remember in antennas gain comes from the narrow 'view' angle) you could easily pick some of the communications from these satellites and if you work hard you can listen to the space station.
As most of theses are not in a geostationary orbit, you need the ability to steer the dish, fortunately a lot of nice Hams have down the work before and have shared it on the net, it does take quite a bit of effort to do it cheaply e.g. rotary encoders and serious PIC programming e.g.
http://www.vk5dj.com/satellite.html or if there is a bit of spare cash it can be bought relatively off the shelf, see AMSATs store
http://www.amsat.orgAMSAT is e pretty good resource
There are also a lot of guys using Software Defined Radio 'dongles' , a google of SDR dongle and satellite bring lots of interesting stuff. One reasonably well organised area is the 'fun-cube dongle' guys. A data transmitting low earth orbit satellite, can be picked up with no steering PC etc and a reasonable antenna, I think the fun cube satellite is still up (they don't last forever!)
As a Ham, with a reasonable job, I went down the path of using a pre made Azimuth and Elevation rotator (Yaesu G5500) with one of AMSATs PC to rotator interfaces and using their PC software to control both the antenna position but also the doppler shift on my radio , an Icom 910 ( a satellite coming at you, transmitting at 400MHz has about 5-10kHz of shift) . Satelites often operate 'split', i.e. transmitting on one freq e.g. 148MHz, receiving on another e.g. 440MHz.
A good program can also 'adjust' the receive and transmit frequencies as the satellite passes overhead.
You can do it a LOT cheaper but a bit more metal bending is required but it is not impossible and there are a LOT of Ham guys who have done it and have posted there success on the net.
If you are all inclined, getting your Ham licence can then allow you to transmit, well legally anyway, and there are a lot of other areas of RF experimentation that you can get your teeth into once you get your 'ticket'. The American amateur radio society, the ARRL has a lot of info.
I have had several conversations via amateur radio satellites, from Adelaide in Southern Australia to other parts of Australia and Indonesia.
Hope this is of help.
Rob