The NASA control center, responsible for a huge chunk of space-faring history, will open its doors to tour groups for the first time in over 30 years, celebrating the Kennedy Space Center's 50th anniversary. Starting this Friday, a "limited number" of tours will take bright-eyed enthusiasts into the Launch Control Center, where all 152 launches were counted down -- visitors will even get to peer at the very same clock. NASA has also granted access to the "bubble room", which is surrounded by windows showing what went on in the firing room just below. The daily tour also throws in a drive-