Space Shuttle Endeavour

2009-05-31 – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, a worker prepares the rail for the closing of the rotating service structure around Space Shuttle Endeavour. The RSS provides protected access to the Shuttle for changeout and servicing of payloads at the pad. The structure is supported by a rotating bridge that pivots about a vertical axis on the west side of the pad's flame trench. (Credit: NASA/Tim Jacobs)