CAPE CANAVERAL, Fla. - With ideal weather expected for Thursday's shuttle launch, European space officials grew increasingly exhilarated as each passing trouble-free hour brought their long-delayed science lab closer to liftoff.

The laboratory, Columbus, was packed aboard space shuttle Atlantis. As NASA breezed through its countdown, the lab and shuttle were declared ready to fly to the International Space Station following a high-level review by managers on Tuesday.

"It's very difficult for a Brit to say that he's excited,'' said Alan Thirkettle, the European Space Agency's station program manager. "But we are very, very excited.

"We're looking forward, seriously, to seeing Columbus be where it belongs,'' he said at a news conference.

Columbus, which has been in the works for a quarter-century, is a seven-metre-long, high-tech laboratory worth $2 billion that was built in Europe and will be controlled from there once it is attached to the space station.

"We'd like to think that now we're at the end of the beginning,'' Thirkettle said.

Forecasters put the odds of good weather at 90 per cent for the late afternoon launch.

In February or March, the Europeans will launch their first space station cargo ship, named Jules Verne, from French Guiana.

Thirkettle noted that these two flights, along with the launch of the European-built Harmony docking compartment aboard Discovery in October, represent nearly 45 tonnes of space station hardware.

"I'm beginning to feel like a scrap metal merchant,'' he said with a smile.

Computer changes, made after laptop networking trouble on the last shuttle flight, will leave NASA with less data than usual regarding Atlantis' condition following liftoff.

Atlantis will not be able to beam down all of the data collected by sensors in the wings that check for impacts, or all of the video images of the empty fuel tank dropping away.

The pictures are useful for spotting any missing sections of foam insulation.

Launch manager LeRoy Cain said engineers prefer having the information while Atlantis is flying in order to help assess its condition for re-entry.

He said laser and camera inspections can also help determine the shuttle's health. No flight rules are being violated by waiting until the spaceship lands to get the wing data and fuel tank pictures, he said.

The extra data collection and picture-taking were implemented after the Columbia disaster in 2003.

A chunk of fuel-tank foam slammed into a Columbia wing at liftoff, and the damage did not become apparent until re-entry, when it was too late. The shuttle broke apart, killing all on board.