Undocking occurred at 10:08 a.m. CDT as Discovery and the ISS were east-northeast of Brazil's capital Brasilia. After springs in the shuttle's docking system provided an initial push, Pilot Pam Melroy, using Discovery's maneuvering thrusters, slowly backed the Shuttle away from the station. The station was parallel to the Earth's surface and sideways to the direction of travel. Discovery, with its nose pointed downward and its right wing in the direction of travel, dropped behind the station, then maneuvered downward.
The final separation burn was executed about 45 minutes after undocking, moving Discovery into a lower, faster orbit to move it away from the larger and more complete station they had helped prepare for the early November arrival of the first resident crew. They added 10 tons to the station's mass, bringing it to about 80 tons. In addition to the total of 27 hours, 19 minutes spent outside the station on the four spacewalks, the astronauts spent 27 hours and 4 minutes inside, completing connections with the new elements and transferring equipment and supplies for that first crew.
During five missions to the ISS, shuttles have spent a total of 33 days, 4 hours and 44 minutes docked to the International Space Station. Crews completed 20 days, 8 hours and 26 minutes of work inside the station, and 2 days, 21 hours and 34 minutes outside during 10 space walks.
Following undocking and separation, Commander Brian Duffy, Melroy, Mission Specialists Leroy Chiao, Bill McArthur, Mike Lopez-Alegria, Jeff Wisoff and Koichi Wakata enjoyed half a day off. Their scheduled sleep period begins at 9:17 p.m. They will be awakened at 5:17 a.m. Saturday morning to prepare for a landing Kennedy Space Center on Sunday afternoon.