First, I learned a lot of my information from a combination of
my amateur radio experience and an awesome talk I sat in at
DEFCON 18. The majority of satellite systems are simple
repeaters. The signal that comes in on a transponder is cleaned,
amplified, and retransmitted. If you know the location and input
frequency, and you pump more effective radiated power than
anybody else, you win. Many satellites also require command
modules. These are used to interpret instructions to boost back
into orbit or at the end of life, de-orbit into a "graveyard"
pattern (or right into the atmosphere itself). Because most
satellite systems are custom, it is a real crapshoot what you
see for commands and security. I suspect that most command
sequences are unencrypted and rely on the fact that a MITM
attack on something in space is fairly hard. Frequencies vary
wildly from MHz to several tens of GHz. Your equipment needs to
put out the right frequency through a dish that is the right
size. Legally speaking, you will at a minim