Space shuttle Atlantis left the International Space Station on Wednesday after a seven-day stay to deliver gear to keep the outpost operating after the shuttle program is retired next year.
Space station flight engineer Nicole Stott joined the six Atlantis astronauts for the return trip home. She is expected to be the last station crewmember to catch a ride on the shuttle. Atlantis is due back at the Kennedy Space Center in Florida on Friday.
"Thank you for a great mission," Jeff Williams, commander of the station, radioed to Stott as the shuttle prepared to leave at 4:53 a.m. EST (0953 GMT). "Bon voyage."
The United States is retiring its three-ship shuttle fleet in 2010 after five more missions to complete construction and outfitting of the $100 billion space station. The station, a project of 16 nations, then will be serviced by Russian, European and Japanese cargo ships, though none can transport the heavy pumps, tanks and gyroscopes carried by the shuttle.
Astronauts will fly exclusively on Russian Soyuz capsules at a cost of about $50 million a seat, Reuters informs.
Returning aboard Atlantis is former station resident Nicole Stott. Friday marks her 91st day in orbit. Stott says she can't wait to see her husband and 7-year-old son, bite into a pizza and drink some icy cola.
Astronaut Randolph Bresnik is looking forward to holding his baby daughter for the first time. She was born last weekend, between his two spacewalks, The Associated Press reports.
NASA's shuttle fleet, the only spacecraft large enough to transport the space station's largest spare parts, is facing retirement in late 2010.
While space station operations are set to continue through 2015, President Obama is considering an option offered by a White House advisory panel and favored by Congress to extend activities aboard the orbital outpost through 2020.
"We accomplished all of our major objectives and then some," said Dan Hartman, NASA's deputy space station program manager, as the Atlantis crew finished its work. "We feel pretty confident about how far that can get us," AFP informs.