Workers inspect External Tank-135 offloaded from the Pegasus barge docked in the turn basin near the Vehicle Assembly Building.

At NASA's Kennedy Space Center in Florida, workers inspect External Tank-135, newly offloaded from the Pegasus barge docked in the turn basin near the Vehicle Assembly Building. Pegasus arrived in Florida on Dec. 26, towed by a solid rocket booster retrieval ship from NASA's Michoud Assembly Facility near New Orleans.

ET-135 will be used to launch space shuttle Discovery on the STS-131 mission to the International Space Station. Launch is targeted for March 18. For information on the components of the space shuttle and the STS-131 mission, visit http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts131/index.html. Photo credit: NASA/Jack Pfaller