Sensors at the end of a 50-foot-boom attached to Discovery's 50-foot robotic arm will scan for near-invisible holes and cracks in the shuttle's left wing caused by micrometeoroids, the dust-sized particles that make up the vast majority of debris circling Earth.
The space debris now also includes a spatula that astronaut Piers Sellers accidentally let go of during a spacewalk Wednesday. NASA said the spatula posed no risk to the space station or shuttle.
Friday's inspection, on Day 11, follows similar scans Discovery's crew conducted with the robotic arm and boom as it closed in on the space station on Day 2 and the close-up examinations of "areas of interest" on Day 4 of the 13-day mission.
Discovery's commander, Steve Lindsey, also maneuvered Discovery into a backflip before docking on the third day so that the space station's two crew members could photograph the shuttle's belly for any signs of damage.
Friday, Discovery's six crew members plan to finish packing up 4,000 pounds of space station trash and equipment they are to haul back to Earth.
NASA managers gave Discovery a clean bill of health and cleared it for landing next Monday.
"We hopefully won't see anything different," astronaut Lisa Nowak, who along with crew mate Stephanie Wilson, operates the robotic arm, said earlier this week. "We hope it looks exactly as it did before."
The extra, late inspection was devised by NASA to make sure there's never again a disaster on par with the Columbia accident which killed seven astronauts in 2003.