The Mars Exploration Rover Mission launch will be carried live on NASA TV. If you have a satellite dish, you can find NASA TV on GE-2, transponder 9C, C-Band, located at 85 degrees West longitude. The frequency is 3880.0 MHz. Polarization is vertical and audio is monaural at 6.8 MHz.

If you have cable, you can put in a request to your cable company to carry NASA TV.

Additional information on NASA TV is available here:

http://www.nasa.gov/multimedia/nasatv/