The doors of the payload canister open to reveal space shuttle Discovery's payload for the STS-119 mission.

On Launch Pad 39A at NASA's Kennedy Space Center in Florida, the doors of the payload canister open to reveal space shuttle Discovery's payload, the integrated truss structure S6 and solar arrays, for the STS-119 mission. The payload will be transferred into the Payload Changeout Room, or PCR. They will be installed in Discovery's payload bay after the shuttle rolls out to the launch pad. Launch of Discovery on the STS-119 mission is scheduled for Feb. 12. During Discovery's 14-day mission, the crew will install the S6 truss segment and its solar arrays to the starboard side of the station, completing the station's backbone, or truss. Photo credit: NASA/Chris Rhodes