On Launch Pad 39A a worker examines the foam insulation on space shuttle Discovery's fuel tank.

On Launch Pad 39A at NASA's Kennedy Space Center in Florida, a worker examines the foam insulation on space shuttle Discovery's external fuel tank. Two cracks on a section of the tank’s metal exterior were found on one of the stringers, which are the composite aluminum ribs located vertically on the tank’s intertank area. Engineers will review images of the cracks to determine the best possible repair method. Discovery's next launch attempt is no earlier than Nov. 30 at 4:02 a.m. EST.

For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Troy Cryder