NASA Prepares for Atlantis Launch Thursday

CAPE CANAVERAL, Feb. 6, 2008 -- Countdown clocks began ticking late Monday afternoon for Thursday's scheduled liftoff of the space shuttle Atlantis.

The shuttle's seven-member crew returned to NASA's launch site Monday to take a new shot at flying to the International Space Station.

Liftoff is set for Thursday afternoon. NASA wrapped up a last repair Sunday night involving a radiator hose. The mission was waylaid in December by a different problem: erratic fuel gauges.

Atlantis' mission now faces only weather concerns, NASA officials said. Forecasters put the odds of acceptable conditions at just 40% because of a cold front and rain expected on launch day. Friday's outlook was much better: 80%.

Atlantis will carry the European Space Agency's science lab, Columbus, to the orbiting outpost.

That will be the second science lab; the United States operates one there already. The largest lab of all, Japan's Kibo, or Hope, will be carried up in sections beginning next month.

Shuttle commander Stephen Frick said he was satisfied with the repairs to the fuel-gauge system, which has troubled NASA for the past few years. He was happy the shuttle team finally succeeded in "nailing this thing down."

"We're feeling very good about this opportunity. We'll keep looking at the weather, but we're very happy about the condition of Atlantis," Frick said.

The fuel-gauge problem was traced to a bad connector at the bottom of the shuttle's huge external fuel tank. The external portion of the connector was replaced with a newly soldered unit.

On Sunday night, a NASA technician was able to tuck a bent radiator hose into its payload bay retraction box.

NASA still hopes to get six shuttle launches off this year, even with Atlantis' two-month delay. The space station faces a 2010 completion date. Then, the three remaining shuttles will be retired so the space agency can focus on returning astronauts to the moon, with eventual plans to fly to Mars.

In a video hookup with family members and friends in Ireland on Monday, space station astronaut Dan Tani was asked by a young boy whether he had ever been to Mars.