NASA on Wednesday said that conditions were right for the Thursday launch of the space shuttle Atlantis, on a mission to deliver a European-built space laboratory to the orbiting International Space Station.
Atlantis is scheduled to blastoff from the Kennedy Space Center at Cape Canaveral, Florida, at 4:31 pm (2131 GMT).
"The countdown is proceeding smoothly," Shuttle Test Director Jeff Spaulding told reporters.
"The vehicle's looking good and the weather's looking good, too," added NASA meteorologist Kathy Winters.
The weather forecast "calls for a 90 percent chance of acceptable conditions at launch time," Winters said.
However if the launch is delayed for any reason by 24 hours, the forecast for good weather would drop to 60 percent, Winters said.
The shuttle's 11-day mission calls for three spacewalks aimed at attaching the European-built Columbus space lab to the ISS.
NASA said a fourth space walk could be added to inspect a faltering mechanism in one of three solar panels serving the station, which would extend shuttle's stay in orbit.
Atlantis astronauts include Leopold Eyharts from France and Hans Schlegel from Germany, both with the European Space Agency (ESA).
With Columbus, Europe will be equipped to tackle scientific experiments with microgravity, considered essential to prepare for long-term space flight.
Until now, only the United States and Russia have had their own laboratories, which form the heart of the ISS.
The new European laboratory will allow astronauts to conduct hundreds of other experiments a year, notably in areas of biotechnology, medicine, materials and fluids.
The shuttle's crew of seven arrived at the Kennedy Space Center on Monday from Houston, Texas where they are based.
