HOUSTON – Atlantis and its seven-man crew were homeward bound after leaving the international space station and checking the thermal casing of their ship Monday for the fiery ride back to Earth.
The space shuttle is due back Wednesday morning.
Good weather is expected at Cape Canaveral, but if that changes, NASA will guide Atlantis to the backup touchdown site in California to give the military time enough time to shoot down a damaged spy satellite without endangering the shuttle.
With pilot Alan Poindexter at the controls, Atlantis undocked from the space station after nine days of linked flight.
"We're looking forward to getting home and we're headed home now," Poindexter said.
The shuttle circled the orbiting complex with its newest science lab, allowing both crews to take pictures, before vanishing into the blackness of space.
"We had a great time over there," radioed shuttle commander Stephen Frick.
"It's a great new room you've added on and we really appreciate it," replied station commander Peggy Whitson.
As soon as Atlantis was flying solo again, its astronauts pulled out their 100-foot, laser-tipped inspection boom and conducted one last survey of the shuttle's nose and wings.
The pre-landing check for micrometeorite damage has become standard procedure ever since Columbia was destroyed during re-entry 5 years ago.
Inspections conducted earlier in the mission found a torn corner on a thermal blanket near the shuttle's tail, but engineers are confident it will stand up to the intense re-entry heat.
Flight director Mike Sarafin congratulated the astronauts for a job well done.
"It's been great to see how well this mission has gone, and we look forward to seeing you back here in Houston and want to wish you a happy landing," Sarafin said.
The two crews devoted almost all of their time together to the European Space Agency's $2 billion Columbus lab, which was dropped off by Atlantis.
But German astronaut Hans Schlegel fell ill after the launch, forcing NASA to pull him from the installation spacewalk and delay the outing.
Schlegel, 56, quickly recovered and helped guide his spacewalking replacement from inside the station. He was well enough to participate in the mission's second spacewalk.
Neither he nor NASA disclosed the nature of his illness.
[Astronauts have suffered from "space sickness," a form of motion sickness caused by adjustments to zero gravity, ever since manned space missions began nearly half a century ago, although there's no indication this is what Schlegel had.]
The station and shuttle crews said a teary farewell Sunday before sealing the hatches between them. Astronaut Daniel Tani was especially emotional as he left the international space station, his home for the past four months.
Tani was supposed to fly home aboard Atlantis in December, but fuel gauge problems delayed the shuttle's trip.
Before the hatches between the spacecraft closed on Sunday, Tani paid tribute to his mother, Rose, who was killed in a car accident while he was in space — "my inspiration" — and his wife, Jane, who "had the hard work while I was having fun."
"I can't wait to get back to her and my two little girls," he said.
Just about the time Atlantis was undocking, another shuttle, Endeavour, was reaching the launch pad in preparation for the next flight to the space station. That liftoff is targeted for March 11.