Weather Clears As NASA Gears Up For Final Discovery Flight

Facing the closure of a short window of opportunity and a potential delay until early December, NASA is gearing up for as many as three consecutive attempts to launch shuttle Discovery on its final flight.

Discovery and six astronauts are tentatively set to blast off from Kennedy Space Center at 3:04 p.m. Friday, the middle of a 10-minute chance to put the shuttle and its crew on course for a rendezvous and docking at the International Space Station.

NASA's Mission Management Team will meet at 5 a.m. to decide whether to fill the shuttle's external tank with more than 500,000 gallons of liquid hydrogen and liquid oxygen in a propellant-loading operation that would begin around 5:39 a.m.

You can watch live NASA TV coverage of the countdown and the tanking operation here in The Flame Trench beginning at 5:30 a.m. Click the NASA TV box on the right to launch our NASA TV viewer and live coverage. We'll also have our live, interactive Cover-It-Live blog up and running throughout the tanking operation and the launch countdown.

And my television colleague Grayson Kamm and I will co-host a live countdown broadcast starting at noon. We'll be broadcasting from the roof of our Kennedy Space Center blockhouse, which is 3.5 miles from launch pad 39A, where Discovery is being prepared for launch. See our ATK-sponsored broadcast on the right side of the page.

Mission commander Steve Lindsey and his crew will begin strapping in to the shuttle just before noon. His crew includes pilot Eric Boe and four mission specialists: Michael Barratt, Alvin Drew, Tim Kopra and Nicole Stott. Stott is one of only three former Kennedy Space Center workers to ascend to the astronaut corps and fly in space.

NASA managers decided early today to forego an opportunity to launch at 3:29 p.m. A cold front brought rain and low-level clouds into the area and as it turned out, forecasters made the right call. NASA would not have been able to launch due to rain within 20 nautical miles of the shuttle landing strip and low-level clouds also would have violated launch rules.

The forecast for Friday calls for a 60 percent chance conditions will be good enough to go. However, NASA will be keeping close tabs on high winds at the shuttle runway and the launch pad.

Here's the synopsis from the Air Force:

Strong surface cold front will move through Central Florida during the early morning hours on Friday. Precipitation will end with the passage of the front, with cloud cover clearing a few hours later with the passage of the mid and upper level trough. Strong northwesterly winds are expected behind the front. This causes concerns for both SLF headwinds as well as launch pad winds. Saturday, the winds increase and become more northerly, increasing the threat of a launch pad wind violation.

NASA must launch Discovery by Sunday or delay its International Space Station outfitting mission to early December. The sun angle on the station between Monday and Nov. 23 will be such that the outpost could not generate enough power and the shuttle could not dispel enough heat to complete the 11-day mission.

Then a three-person crew is departing the station Nov. 29, and a shuttle mission in that timeframe would interrupt that operation.

The next window of opportunity would extend from Dec. 1 through Dec. 5.