Space shuttle Endeavour flies over Ellington Field in Houston atop the shuttle aircraft carrier Wednesday, Sept. 19, 2012. Endeavour is making a final trek across the country to the California Science Center in Los Angeles, where it will be permanently displayed. (AP Photo/David J. Phillip)

Photo by: David J. Phillip

Space shuttle Endeavour flies over Ellington Field in Houston atop the shuttle aircraft carrier Wednesday, Sept. 19, 2012. Endeavour is making a final trek across the country to the California Science Center in Los Angeles, where it will be permanently displayed. (AP Photo/David J. Phillip)