Bay 3 a worker maneuvers space shuttle main engine No. 1 toward the aft opening for installation.

In Orbiter Processing Facility bay 3 at NASA's Kennedy Space Center in Florida, a worker maneuvers space shuttle main engine No. 1 toward the aft opening in space shuttle Discovery for installation. 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