NASA's Associate Administrator for Space Operations William H. Gerstenmaier points to a piece of foam which fell from the space shuttle Discovery's external tank during a news conference at the Kennedy Space Center in Cape Canaveral, Florida, July 3, 2006. Gerstenmaier announced that the planned launch of Discovery on July 4 would continue after engineers determined that loss of the foam would not jeopardize the vehicle. REUTERS/Joe Skipper (UNITED STATES)