The workload on the international space station was sometimes tough and grueling for Frank Culbertson, its former commander.

But the location made it all worthwhile for the retired Navy captain, who along with his Russian crewmates continued their trip back to Earth on Sunday aboard space shuttle Endeavour.

"Being in space is a real treat anyway so it doesn't really matter how hard you work," Culbertson said. "You're still in space and you still should be happy about that."

Culbertson, along with cosmonauts Vladimir Dezhurov and Mikhail Tyurin, had lived on space station Alpha since August.

Their successors, Russian commander Yuri Onufrienko and Americans Daniel Bursch and Carl Walz, arrived Dec. 7 aboard Endeavour and will spend nearly six months in orbit.

Mission Control awakened Culbertson, Dezhurov, Tyurin and the four other astronauts aboard Endeavour on Sunday with a recording of Bing Crosby singing "I'll Be Home for Christmas."

Later in the morning, the shuttle crew released a small glittering satellite from a can in the payload bay. The sphere, called Starshine, is covered with nearly 900 mirrors to reflect sunlight and provide easy tracking by youngsters around the world. Students helped polish the mirrors.

The shuttle left the space station on Saturday and is scheduled to land on Monday. Mission Control said Sunday that the weather for the Florida touchdown was looking much more promising than earlier forecasts.

Before leaving, Culbertson gave the new space station residents a holiday treat: a small fabric Christmas tree decorated with gifts for each day until Dec. 25 and candy canes.

"To international space station Alpha, thank you for being a wonderful home," Culbertson said after the two spacecraft had separated and the shuttle headed away.

Endeavour's departure was delayed so the shuttle could move the orbiting complex away from a chunk of a 30-year-old Russian rocket that might have passed within three miles of Alpha on Sunday.