CAPE CANAVERAL, Fla. - After an intense weekend of repairs and reviews, NASA cleared space shuttle Discovery for liftoff Monday night on a space station construction mission.
But gusty wind threatened to push the launch later into the week.
Meteorologist John Weems said there was a 70 percent chance that stiff crosswind would prevent Discovery from taking off on NASA's 100th space shuttle mission, not only Monday but Tuesday, too.
''It really depends upon the wind direction,'' Weems said Sunday.
Discovery was supposed to depart for the international space station last Thursday, but was grounded by concerns over bolts on the external fuel tank. In addition, a sluggish valve in the shuttle's engine compartment had to be replaced.
Shuttle managers wrapped up the bolt issue Sunday and declared Discovery safe to fly.
While reviewing film from Atlantis' launch last month, engineers noticed Wednesday that one of the bolts on the external fuel tank did not retract fully when the tank separated from the shuttle eight minutes into the flight as planned.
NASA immediately put together three teams to investigate the bolt malfunction and determine whether the problem might affect Discovery.
As of Sunday, after reviewing piles of film, engineers had identified about a half-dozen shuttle launches with similar bolt problems, said test director Steve Altemus. The malfunctioning bolts did not cause any of the fuel tanks to tilt or tumble when jettisoned, he said.
''That's good news,'' Altemus said.
The main concern last week was that a protruding bolt could put a spin on the 153-foot, rust-colored tank and cause the tank to slam into the space shuttle. Such a collision could be catastrophic.
NASA wants to launch Discovery as soon as possible, in order for the international space station to be inhabited early next month. The space station's first permanent crew cannot lift off until Discovery has visited the 240-mile-high outpost.
Discovery's seven astronauts will attach two new segments to the space station: a girderlike truss that holds motion-control gyroscopes and antennas, and a shuttle docking port. Four spacewalks are planned on four consecutive days.
It is NASA's first space station construction mission in two years.
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