Discovery is ready to roll out of the Orbiter Processing Facility bay 3 on its transporter for the short trip to the Vehicle Assembly Building.

Space shuttle Discovery is ready to roll out of the Orbiter Processing Facility bay 3 on its transporter for the short trip to the Vehicle Assembly Building. In the VAB, the shuttle will be lifted and mated with the external tank and solid rocket boosters on the mobile launcher platform. Discovery is targeted for launch to the International Space Station for mission STS-120 on 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/Amanda Diller