The US space shuttle Discovery backed away from the International Space Station on Wednesday, leaving behind a Japanese research laboratory, a new crewmember and high hopes for the outpost's completion by 2010.
Pilot Ken Ham pulsed Discovery's steering jets to slip away from the station's Harmony docking port at 7:42 a.m. EDT(1142 GMT).
The shuttle arrived at the station on June 2 to deliver Japan's primary contribution to the $100 billion complex, the 37-foot-long (11-metre-long) Kibo laboratory.
"We hope we left them a better, more capable station than when we arrived," Discovery commander Mark Kelly radioed to flight controllers as the shuttle prepared for undocking.
From aboard the station, Greg Chamitoff, who replaced returning flight engineer Garrett Reisman, replied, "It was amazing how much got done here. We wish you guys a terrific flight back and awesome landing."
Discovery is due to land at at the Kennedy Space Center in Florida on Saturday after completing the third of five shuttle missions NASA has planned for this year.
NASA's next flight is scheduled for October when shuttle Atlantis lifts off for a final servicing call to the Hubble Space Telescope.
NASA has 10 missions remaining before the shuttle fleet is retired in 2010 and work begins on a new ship that can travel to the moon as well as the space station.
(Editing by Michael Christie and Bill Trott)