is due to expire next year. "endeavour" in april. only twice more will we have the majesty, the awe, and let's be honest, the trepidation. of watching a shuttle liftoff. we wish the "discovery" astronauts a successful 11 days in space. we will track that mission. we'll see you back here tomorrow. parker spitzer starts right now. good evening. >> welcome to our program. >> tonight in libya, moammar gadhafi is hanging on by his fingernail and i'm not sure how much longer this can go on. many libyan cities have now fallen to the rebels. it fathers turning point for the future of moammar gadhafi's libya will be the battle of tripoli. the capital city is his last real stronghold. here are the cities now in control of the rebels. in the eastern part of the