STS-79 Commander William F. Readdy arrives at KSC's Shuttle Landing Facility with five fellow astronauts, ready to participate in the Terminal Countdown Demonstration Test (TCDT). The TCDT is a dress rehearsal for launch for the flight crew and launch team. Over the next several days, the astronauts will take part in training exercises at the launch pad that will culminate in a simulated launch countdown. The Space Shuttle Atlantis is being prepared for liftoff on STS-79 around Sept. 12.