Atlantis and its four-member crew left the International Space Station Tuesday after restocking it with a year's worth of supplies.
On the eve of NASA's historic, wheel-stopping end to the shuttle program, the four astronauts making the final journey completed one last task. They released the very last satellite to be launched from a space shuttle. It popped out of a can Wednesday: a little 8-pound box covered with experimental solar cells.
Over the three decades of the shuttle era, 180 satellites and other spacecraft have been deployed by the entire fleet.
Excellent weather was forecast to wind up the 135th flight of the space shuttle program. Atlantis is planned to land at 2:56 a.m. (PT) at Kennedy Space Center in Florida.
"It's going to be tough," shuttle commander Christopher Ferguson said in a series of TV interviews. "It's going to be an emotional moment for a lot of people who have dedicated their lives to the shuttle program for 30 years. But we're going to try to keep it upbeat."
Meantime, NASA is about to lay off some 2,000 shuttle workers at Kennedy Space Center. They're expected to get pink slips on Friday, just one day after Atlantis returns to Earth.
The Associated Press contributed to this story