Satellite WILL work through RG59 if that's what you have (not the best, but OK). It does need to be a direct physical connection, as the power for the Tailgater is carried in the wires from the receiver.
If you have the most common setup, there is a cable from the exterior to the amplifier for your rooftop antenna, a cable from the amplifier to the rooftop antenna itself, and a cable from the amplifier to your entertainment center(possibly two cables to entertainment centers). You can remove the amplifier and install a connector between the cable to the exterior and the cable to the entertainment center where your satellite receiver is.
The best solution is to add a second cable from the exterior to the entertainment center for the satellite and leave your rooftop antenna for times you don't need/want to set up the satellite.
Doug