The International Space Station crew goes to sleep at 9:43 p.m. EDT Tuesday followed by the space shuttle Discovery crew at 10:13 p.m. Wake up comes at 5:13 a.m. Wednesday to start the final hours of the joint mission. Discovery is set undock from the station at 3:53 p.m. after the crew bids farewell to its temporary home and the Expedition 18 crew, leaving behind Japanese astronaut Koichi Wakata and bringing home Sandy Magnus after four months aboard the station.

All the crew members aboard Discovery and the space station gathered in the station's Harmony module Tuesday morning and spoke to the President of the United States, members of Congress and students. The president was joined in the White House's Roosevelt Room by Sens. Kay Bailey Hutchison and Bill Nelson, along with Reps. Gabrielle Giffords, Bart Gordon, Parker Griffith, Suzanne Kosmas and Alan Mollohan. The schoolchildren were from the Boys and Girls Club of Washington, D.C., Southeast Elementary Academy of Washington, the Louise Archer Elementary School and Thoreau Middle School in Virginia, and the Parkland Magnet Middle School for Aerospace Engineering in Maryland.