CAPE CANAVERAL, Fla. -- The payload canister containing the S6 truss and solar arrays arrives at Launch Pad 39A at NASA's Kennedy Space Center in Florida. The canister sits below the Payload Changeout Room, or PCR. It will be lifted up to the PCR and space shuttle Discovery's payload transferred inside. After Discovery rolls out to the pad, the payload will be installed in the shuttle's payload bay. 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/Jim Grossmann

CAPE CANAVERAL, Fla. -- The payload canister containing the S6 truss and solar arrays leaves the Canister Rotation Facility at NASA's Kennedy Space Center in Florida to head for Launch Pad 39A. The truss and arrays are space shuttle Discovery's payload for the STS-119 mission to the International Space Station. 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/Jim Grossmann

CAPE CANAVERAL, Fla. -- The payload canister containing the S6 truss and solar arrays arrives at Launch Pad 39A at NASA's Kennedy Space Center in Florida. The canister sits below the Payload Changeout Room, or PCR. It will be lifted up to the PCR and space shuttle Discovery's payload transferred inside. After Discovery rolls out to the pad, the payload will be installed in the shuttle's payload bay. 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/Jim Grossmann

CAPE CANAVERAL, Fla. -- The payload canister containing the S6 truss and solar arrays arrives at Launch Pad 39A at NASA's Kennedy Space Center in Florida. The canister sits below the Payload Changeout Room, or PCR. It will be lifted up to the PCR and space shuttle Discovery's payload transferred inside. After Discovery rolls out to the pad, the payload will be installed in the shuttle's payload bay. 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/Jim Grossmann

CAPE CANAVERAL, Fla. -- With red umbilical lines attached, the payload containing space shuttle Discovery's S6 truss and solar arrays is lifted up to the Payload Changeout Room, or PCR, on Launch Pad 39A at NASA's Kennedy Space Center in Florida. The payload will be transferred inside the PCR where it will wait until Discovery rolls out to the pad. Then the payload will be installed in the shuttle's payload bay. 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/Jim Grossmann

CAPE CANAVERAL, Fla. -- With red umbilical lines attached, the payload containing space shuttle Discovery's S6 truss and solar arrays is lifted up to the Payload Changeout Room, or PCR, on Launch Pad 39A at NASA's Kennedy Space Center in Florida. The payload will be transferred inside the PCR where it will wait until Discovery rolls out to the pad. Then the payload will be installed in the shuttle's payload bay. 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/Jim Grossmann

CAPE CANAVERAL, Fla. -- With red umbilical lines attached, the payload containing space shuttle Discovery's S6 truss and solar arrays is lifted up to the Payload Changeout Room, or PCR, on Launch Pad 39A at NASA's Kennedy Space Center in Florida. The payload will be transferred inside the PCR where it will wait until Discovery rolls out to the pad. Then the payload will be installed in the shuttle's payload bay. 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/Jim Grossmann