You can see the Space Shuttle Discovery's launch tonight at 8:20 pm CDT (01:20 UTC). We are streaming live online video from NASA TV: watch it here free.
This important mission will complete construction of the large solar panel array on the International Space Station (ISS) and make it the second brightest object in the evening sky. The ISS will be even brighter than Venus. After completion of this mission, the ISS will be even easier to see with the naked eye. Look here for a live graphic of the ISS's position and instructions on how to see it.