Shuttle Launch On, Despite Gloomy Forecast
NASA began moving the scaffolding that protects the space shuttle and readied for launch early Thursday, despite lingering clouds and other weather woes that cast doubt on Discovery's blast-off.
Launch beneath a nearly full moon was set for 9:35 p.m. EST with the shuttle and its seven astronauts headed to the international space station on a rewiring mission as construction continues on the orbiting lab.
Fueling of the shuttle's external tank began as scheduled at 11:41 a.m.
As NASA resolved technical concerns Wednesday, two lurking weather problems suggested a less than even chance of tonight's launch. The official likelihood of good weather is only 40 percent and that drops to 30 percent Friday, nudging back up to 40 percent Saturday.
The biggest problem is a bank of low clouds that are sticking around because of a cold front. NASA rules prohibit launching in low clouds because clear skies are needed to observe the shuttle during ascent and the shuttle commander needs visibility if an emergency landing were required.
On top of that, all three overseas emergency landing sites in Spain and France also have bleak forecasts.
If Discovery doesn't launch tonight, Friday looks even worse with a prediction of high winds. The next best weather for launch really doesn't come until next Tuesday, shuttle weather officer Kathy Winters said.
NASA usually sloshes through weather problems for daytime summer launch tries and has easier times later in the year. Weather officer Tech. Sgt. Matt Timmerman said when he was assigned to Discovery's December night launch he figured the skies would be more cooperative.
'This is just a timing factor,' Timmerman said. 'It's more unfortunate than unusual.'
NASA has through Dec. 17 to launch the shuttle on its mission so Discovery won't be in orbit when the new year starts because NASA worries about a computer change-of-date problem. But if Discovery is still grounded by Dec. 18, NASA may decide to keep trying anyway through Dec. 26.
NASA wrestled with two technical concerns before resolving them Wednesday.
Along with spacewalking astronauts rewiring the space station, Discovery will deliver a 2-ton addition and replace one of the station's three crew members.
This is the first planned night launch in four years.
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