Update: Front Could Affect Friday Launch

A weather front could push clouds and showers near Cape Canaveral on Friday, but there's a 60 percent chance Endeavour will be able to launch Friday, officials said today during a countdown status briefing at Kennedy Space Center.

The chance is worse - 40 percent - on Saturday, "but there will be a lot of clouds and a chance for some showers ahead of the front," said shuttle weather officer Kathy Winters.

"As we get into launch time, our main concerns will be the thick clouds that could roll in with the front, and also any showers within 20 nautical miles of the shuttle landing facility," Winters said.

Here's a link to the forecast.

Officials said shuttle preparations for Friday's 7:55 p.m. launch time are proceeding well.

"Our systems are in great shape," said Jeff Spaulding, NASA test director. "We're tracking no issues at this point."

Pressurization of the shuttle's main propulsion system and orbital maneuvering system tanks was completed this morning, and the orbiter's aft and mid-body compartments are closed for flight, Spaulding said.

NASA hopes to launch Endeavour by Nov. 25. Between Nov. 26 and Dec. 17, the sun's angle would not allow the International Space Station to generate enough power, or dispel enough heat, to support a docked shuttle.

Endeavour's launch countdown begins at 10 p.m. today, about six hours after the shuttle's crew of seven astronauts is expected to arrive at the space center. You can watch NASA TV's live coverage of the arrival here at The Flame Trench, by clicking the NASA TV viewer above.

After the countdown clock starts, checkout and configuration of avionics systems will begin, Spaulding said. On Wednesday, workers will prepare on-board cryo-reactant tanks used to produce electrical power on orbit.

Launch pad 39A's Rotating Service Structure is scheduled to be retracted at 11:30 p.m. Thursday, followed by external tank fueling at 10:30 a.m. Friday.

Endeavour's launch window lasts 10 minutes, starting at 7:50 p.m. NASA aims to launch in the middle of the window.

Landing is planned at about 2 p.m. Nov. 29.