Bay 3 workers make adjustments to install space shuttle main engine No. 3 in space shuttle Discovery.

In Orbiter Processing Facility bay 3 at NASA's Kennedy Space Center in Florida, workers make adjustments to install space shuttle main engine No. 3 in space shuttle Discovery. Each engine is 14 feet long, weighs about 6,700 pounds, and is 7.5 feet in diameter at the end of the nozzle. Discovery is being processed for its next mission, STS-119, targeted for launch on Feb. 12, 2009. Discovery and its crew will deliver integrated truss structure 6 (S6) and solar arrays to the International Space Station. Photo credit: NASA/Dimitri Gerondidakis