The rigorous inspection is a safety measure implemented in the aftermath of the 2003 Space Shuttle disaster.
broke up upon re-entry to Earth's atmosphere. A section of foam that broke off during lift-off is believed to have damaged shielding on the orbiter's wing and was blamed for the deadly mishap.
To avert a possible recurrence, 's crew deployed laser, digital, and video cameras attached to the shuttle's robotic arm. The cameras took images of the shuttle's wings and nose cap, and NASA officials say the examination is capable of revealing cracks or other damage as small as three millimeters.
Tuesday, launch video showed bits of foam falling away from 's massive external fuel tank. But NASA officials said there was little risk of damage, as the foam fell away after the shuttle had gained sufficient altitude so that the thinner atmosphere did not accelerate the particles to a dangerous speed.
NASA says 's 12-day mission could be extended to a 13th day. Thursday, the shuttle is to arrive at the International Space Station to deliver supplies, equipment and a crewmember. On board is Mission Specialist Thomas Reiter of Germany, who will remain on the space station for six months.