The space shuttle Endeavour has undocked from the International Space Station at the end of the longest mission of its kind to the station.
The 12-day rendezvous saw Endeavour's crew install the first part of a Japanese research laboratory and assemble a Canadian robot.
The robot will be used to handle future components delivered to the space station.
The shuttle is due to land in Florida on Wednesday.
"We had a great time here," shuttle commander Dominic Gorie told the station crew before undocking.
"It's a strange feeling to want to see your families but not want to leave a wonderful place."
LeRoy Cain, chairman of the mission management team, said the mission had been "extraordinary".
"It's just been a textbook mission up and down the line in every way that I look at it," he added.
French astronaut Leopold Eyharts is returning home on the shuttle after living onboard the ISS. Astronaut Garrett Reisman has replaced him.
The three astronauts on the space station are awaiting the docking of Europe's new cargo carrier, Jules Verne, on 3 April.
One week later, a Russian Soyuz spacecraft will arrive, carrying a new space station crew.
The next shuttle visit to the ISS is scheduled for late May, when Discovery is due to arrive with the Japanese lab, Kibo.
But the Hubble Space Telescope mission, due at the end of August, might have to be postponed.
LeRoy Cain said a slowdown in shuttle fuel-tank production could delay the flight.