A crawler transporter moves Space Shuttle Discovery secured atop a mobile launch platform on a balmy Florida morning.

A crawler transporter moves Space Shuttle Discovery, secured atop a mobile launch platform, along the crawlerway from the Vehicle Assembly Building to Launch Pad 39A on a balmy Florida morning. First motion out of the VAB was at 6:47 a.m. EDT. The crawler transporter, mobile launch platform and unfueled space shuttle weigh a total of 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