A rainbow can be seen in the spray from the water truck traveling on its move from the Vehicle Assembly Building to Launch Pad 39A.

A rainbow can be seen in the spray from the water truck traveling ahead of Space Shuttle Discovery on its move from the Vehicle Assembly Building to Launch Pad 39A. First motion out of the VAB was at 6:47 a.m. EDT. The water dampens the rocks on the crawlerway, reducing the amount of dust churned up by the passage of the shuttle. The crawler transporter carrying the mobile launch platform and unfueled space shuttle weighs approximately 17.5 million pounds. Rollout is a milestone for Discovery's launch to the International Space Station on mission STS-120, targeted for Oct. 23. The crew will be delivering and installing the Italian-built U.S. Node 2, named Harmony. The pressurized module will act as an internal connecting port and passageway to additional international science labs and cargo spacecraft. In addition to increasing the living and working space inside the station, it also will serve as a work platform outside for the station's robotic arm. Photo credit: NASA/George Shelton