December 7, 2006
Shuttle Launch Tonight Iffy, Friday Off
CAPE CANAVERAL, Fla. -- NASA officials hoped an opening in the cloud cover would allow space shuttle Discovery to lift off Thursday for the first night launch in four years, starting a complex mission to rewire the international space station.
Despite just a 40 percent chance of favorable weather at the 9:35 p.m. EST launch time, Discovery's seven astronauts donned their orange spacesuits and boarded the van for the trip to the launch pad. While her crew mates suited up, Sunita Williams, who will stay at the space station for six months, jokingly did bodybuilder muscle poses for the camera.Earlier in the afternoon, the astronauts - five of whom are going to space for the first time - toasted each other with water at a pre-launch meal.
As dusk arrived, launch controllers grew more concerned about high winds, although they were slightly more optimistic about getting a break in the clouds.
If the space shuttle didn't get off the ground Thursday night, NASA likely would wait until Saturday before trying again. The Friday forecast was even worse, with only a 10 percent chance for launching.
"Unless the weather changes, which in case you haven't noticed has been observed to occur in Florida from time to time ... I doubt we would even try to tank tomorrow if we don't make it for today," NASA Administrator Michael Griffin told The Associated Press on Thursday.
Not only was the sky thick with clouds over Kennedy Space Center, but the weather wasn't favorable at the shuttle's three emergency landing sites in Spain and France. NASA won't launch unless one of those sites has good weather.
Too many clouds prevent the necessary observation of the shuttle during its ascent, and the shuttle commander needs visibility if an emergency landing is required.
The best opportunity for launching over the next several days was Tuesday, said shuttle weather forecaster Matt Timmermann.
At the beginning of next week, "we see an improving trend," he said. "The winds get lighter and it gets drier."
During the 12-day mission, Discovery's astronauts will rewire the space station, bring up a new 2-ton addition to the space lab and rotate out one of the three crew members at the space station.
NASA had required daylight liftoffs for the three launches after the 2003 Columbia accident to make sure the agency could get good daytime photos of the external fuel tank in case debris fell from it during launch. Foam breaking off the tank and striking Columbia's wing at liftoff caused the damage that led to the disaster that killed seven astronauts.
But NASA officials were comfortable with the acceptable levels of foam loss during the last two liftoffs and believe radar will be able to spot pieces falling from Discovery's tank.
Griffin said he felt no pressure to stick to the launch schedule, despite NASA's desire to go up before Dec. 17 so that Discovery is back on the ground for the new year. Shuttle computers aren't designed to make the change from the 365th day of the old year to the first day of the new year while in flight. The space agency has figured out a solution for the New Year's Day problem, but managers are reluctant to try it if they don't have to do so.
If Discovery is still grounded by Dec. 18, NASA may decide to keep trying anyway through Dec. 26.
"We've got days and days, and we're not even worrying about the clock problem," Griffin said. "The clock problem is an annoyance but it's not a real problem in the sense that we know how to deal with it."
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