STS-121/Discovery Preflight Briefing Program OverviewWayne Hale (Space Shuttle Program Manager) opens with a short video of the external tank operation and the Shuttle roll out to the launch pad. Kirk Shireman (International Space Station Program Deputy Manager) shows a video of International Space Station activities which included replacement of the remote power switch, unloading of cargo, Earth observation (over 23,000 photos taken), exercises, and replacement of the Camera during a spacewalk.