Atlantis preparing for its journey back to Earth [Reuters/Nasa] 

The space shuttle Atlantis has begun its journey back to Earth after a nine-day stay at the International Space Station in which crew members installed new solar energy panels and fixed wayward computers.

 

Atlantis undocked from the station, then performed a final inspection of its heat shield on Tuesday before it set out for Earth.

 

It is due to return on Thursday.

 

Nasa officials said they did not expect the scan using the shuttle's sensor-laden robot arm to turn up any shield damage, but the data was being studied.

 

"We'll know more tomorrow, but I don't anticipate any problems," flight director Cathy Koerner said at Johnson Space Centre.

 

During one of four spacewalks performed at the station, astronaut Danny Olivas repaired a torn thermal blanket near the shuttle's tail as a precaution against heat damage when Atlantis re-enters the earth's atmosphere.

 

Atlantis undocked successfully from the 
International Space Station [Reuters/Nasa]
Heat shield damage that went undetected led to the 2003 break-up of shuttle Columbia as it returned from space. The seven astronauts on board were killed.

 

Atlantis completed the main task of its mission by installing a new set of solar energy panels on the station to generate more electricity for the growing complex.

 

European and Japanese-built modules are to be added on flights later this year and early in 2008 as Nasa tries to complete the half-finished station before the shuttle fleet is retired in 2010.

 

Computer crash

 

The assembly work was overshadowed by a computer crash on the station that raised fears the outpost, manned continuously since 2000, would have to be temporarily abandoned.

 

The computers keep the station properly positioned for communications and power generation from the sun.

 

The crash was thought to be caused by a still-undetermined electrical problem.

 

After skipping two nights' sleep, station commander Fyodor Yurchikhin and flight engineer Oleg Kotov rewired the computers and they were fully revived over the weekend.

 

Atlantis was scheduled to land at the Kennedy Space Centre in Florida at 1:54 pm EDT (17:54 GMT) on Thursday, but Nasa officials said the shuttle has enough supplies to stay in space until Sunday if weather or other problems force a delay.

Source: Agencies