(04/23/2000) -- The darkening sky at sunset provides a dramatic backdrop for Space Shuttle Atlantis on Launch Pad 39A. Spectators (bottom) wait for the rollback of the Rotating Service Structure to reveal the orbiter. In the photo only the orange external tank and white solid rocket booster are visible. Atlantis is targeted for liftoff at 4:15 p.m. EDT April 24 on mission STS-101. The mission will take the crew to the International Space Station to deliver logistics and supplies and prepare the Station for the arrival of the Zvezda Service Module, expected to be launched by Russia in July 2000. Also, the crew will conduct one space walk. This will be the third assembly flight to the Space Station