New York Mayor Michael Bloomberg, center, talks about the construction around the site where the World Trade Center once stood to NASA Deputy Administrator Lori Garver, right, and members of the STS-135 crew including commander Chris Ferguson, left, mission specialist Rex Walheim, second right, and pilot Doug Hurley, rear, as they tour the area, Wednesday evening, Aug. 18, 2011, in New York. Photo Credit: (NASA/Paul E. Alers)