(Agencies)
Updated: 2008-02-07 15:17

CAPE CANAVERAL, Fla. - NASA prepared to launch the space shuttle Atlantis on Thursday on a long-delayed mission to deliver a $1.9 billion European laboratory to the International Space Station, but weather threatened another postponement.

The space shuttle Atlantis is shown as the rotating service structure is rolled back for launch at the Kennedy Space Center in Cape Canaveral, Florida February 6, 2008. Atlantis is now expected to carry a crew of seven astronauts on a mission to the International Space Station on February 7. [Agencies]

Atlantis was scheduled to lift off at 2:45 p.m. (1945 GMT) from the Kennedy Space Center in Florida on the first space shuttle mission of the year.

But the US space agency's weather experts offered only a 30 percent chance of a launch as a cold front that spawned killer tornadoes in the southeastern United States headed toward central Florida.

The front was expected to have lost much of its strength by the time it reaches the Cape Canaveral area, but meteorologists said it could bring rain, clouds and perhaps thunderstorms.

Atlantis' mission was twice delayed in December by technical problems with an emergency engine cutoff system.

The shuttle will carry Columbus, Europe's first permanent space lab, into orbit, where astronauts will attach it to the space station during Atlantis' weeklong visit.

The European Space Agency has been waiting for the delivery of Columbus since 2002. It was first postponed by Russian delays launching the space station's service module, then by the 2003 destruction of space shuttle Columbia, which grounded the shuttle fleet for 2 1/2 years.

Twenty-three feet (7 metres) long and nearly 15 feet (4.5 metres) in diameter, Columbus has room enough for three crew members to work on experiments. It will be launched with a biolab for cell and tissue studies and an experiment to study the effects of weightlessness on the human body.

ESA is counting on Columbus' successful deployment and the March 8 launch of a cargo ship to proceed with future space programs, including participation in NASA's plan to return humans to the surface of the moon.

Atlantis will also carry European astronaut Leopold Eyharts to the space station, where he will oversee the setup and activation of Columbus.

Eyharts, 50, spent three weeks aboard Russia's now-defunct Mir space station nearly a decade ago. He will replace NASA astronaut Dan Tani as a member of the space station's three-person resident crew.

NASA plans to quickly follow Columbus' launch with the first flight for Japan's Kibo complex.

The agency has 13 remaining missions on the shuttle's roster before the fleet is retired in 2010.

In addition to 12 space station construction and resupply flights, NASA plans a mission in August or September to service the Hubble Space Telescope.