This image released by NASA and taken by the crew of the International Space Station shows Discovery as it performed a back flip. The operation allowed the space station crew to photograph the underside of the orbiter to check for damage. (NASA AFP/Getty Images)
A photo taken by the Discovery crew shows the external fuel tank as it is jettisoned after launch. Initial analysis shows that a large piece of foam, not visibile in this photo, separated from the tank during ascent. (NASA AFP/Getty Images)
