The weather was forecast to be fine for the landing of the Atlantis and its seven crew members scheduled at 9:07 am (1407 GMT) at the Kennedy Space Center here, the National Aeronautics and Space Administration said.

Music woke the seven astronauts just before 0600 GMT so they could begin preparations for re-entry.

"Good morning Atlantis, and a special good morning to you today Dick, and happy entry day," Shannon Lucid said at mission control center in Houston, Texas, after broadcasting "Hail to the Spirit of Liberty" by American composer John Philip Sousa, known for his patriotic marches.

"Thank you Shannon, and thanks to my wife Lisa and my sons Jack and Sam for a great piece of wake up music. We are really looking for landing today," co-pilot Alan Poindexter replied.

Preparations were to begin in earnest at 0905 GMT, and an hour later the two doors of the orbiter's cargo bay were to be closed.

The astronauts were to don their orange space suits at around 1130 GMT and buckle their seatbelts at 1200 GMT.

If the weather remains favorable, the flight's re-entry director will give a green light at around 1240 GMT for exiting Earth's orbit at 1300 GMT.

Commander Steve Frick will then fire up Atlantis' engines for two and a half minutes to slow it down sightly as it surges around Earth at up to 25 times the speed of sound.

The slight braking will be enough to hurtle Atlantis into an hour-long descent toward Florida, over the Gulf of Mexico and past western Cuba before touching down at Kennedy, near Cape Canaveral, Florida.

If conditions prevent landing during the first window of opportunity, there will be another 90 minutes later. Failing that, Atlantis can try landing at Edwards Air Force base in California at 1542 GMT.

The shuttle must land by Friday, when its hydrogen batteries will run out.

But NASA will do its best to land Atlantis as early as possible before the Navy attempts to fire missiles at an out-of-control spy satellite hurtling to Earth, which could come as early as later Wednesday, in the Pacific.

Flight director Brian Lunney said Tuesday there was no sense of pressure to land in a hurry.

"I'm not going to land the vehicle until it's safe to do so," he told reporters.

The Pentagon official on Tuesday said the touchdown of Atlantis would open a window of opportunity for the US military to shoot down a defunct US satellite before it tumbles into the Earth's atmosphere.

US warships were already moving into position for the operation, they said.

Armed with two specially modified interceptor missiles, the USS Lake Erie has been tasked to intercept the satellite over the Pacific and shoot it down into the ocean, the officials said, adding that a cruiser, the Aegis, is already in waters off Hawaii.

"There is a very low risk because our orbits are quite different," Atlantis Commander Frick said of the two operations.

"The satellite is well below us (where) we are now, but of course we are going to land before they break up that satellite."

Atlantis is returning from a two-week mission during which the crew installed a European laboratory at the orbiting International Space Station.

On Tuesday the astronauts on board were preparing for their return to Earth, after separating from the space station early Monday, NASA said.

Inspections of the shuttle's thermal protection tiles on its wings and nose showed there was no damage.

NASA has paid special attention to the protective tiles since 2003 when its shuttle Columbia burned up on re-entry into the atmosphere because of damaged shielding, killing all seven on board.

Hitching a ride home on Atlantis is American Daniel Tani, a master spacewalker and operator of robotic arms, who had worked on the station since October.

German astronaut Hans Schlegel, who helped install the Columbus laboratory, is also coming home.

The spaceship left behind at the ISS Frenchman LeopoldEyharts,amedical researcher and engineer from France's National Centerof Space Studies.

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