On Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers check the movement of space shuttle Discovery's payload bay doors as they close around the cargo. The cargo consists of the integrated truss structure S6 and solar arrays for the STS-119 mission to the International Space Station. During Discovery's 14-day mission, the shuttle's seven astronauts will install the S6 truss to the starboard side of the space station, completing the station's truss, or backbone. Launch of Discovery on the STS-119 mission is targeted for Feb. 12. Photo credit: NASA/Dimitri Gerondidakis