Live in Orbit: NASA Watches Windy Weather

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Discovery's astronauts have loaded atmospheric reentry software into the shuttle's flight computers in advance of a planned landing early this afternoon at Kennedy Space Center while flight directors keep a close eye on the weather.

The shuttle and its crew are scheduled to touchdown at KSC's three-mile runway at 1:39 p.m. and would have a second opportunity, if need be, at 3:14 p.m.

NASA astronaut George Zamka radioed up a detailed forecast to the astronauts.

It calls for scattered clouds at 4,000 feet and 20,000 feet, and there is a chance that the cloud deck at 4,000 feet could build up to the point where it would violate flight rules. About half the sky must be clear before 8,000 feet and a visibility of five miles both are required to proceed with landing.

Zamka told the crew that sustained winds out of the south would be 15 knots with gusts up to 23 knots, and a headwind of 22 knots is expected. The headwind limit is 25 knots.

Runway 18 -- the north end of the shuttle landing strip -- will be the preferred runway today because of the wind direction. Runway 33 on the south end would result in a serious tailwind and the tailwind limit is a sustained wind of 10 knots with gusts to 15 knots.