Live: Fueling of shuttle Discovery begins

12:05 p.m. update: Fueling about halfway complete and no issues to report.

Fueling of the space shuttle Discovery has begun for a planned flight tonight from Kennedy Space Center.

Skies are mostly clear, the weather report looks solid. Launch time is 7:43 p.m.

After cooling the pipes that carry super-cold propellants into the tank around 10:18 a.m., the fuel began to flow at 10:28 a.m.

It will be during this filling of the towering orange external tank that we'll find out whether repair crews fixed a leaky hydrogen gas valve, which was the reason that Discovery and seven astronauts did not launch on Wednesday night.

As it stands, Discovery and its crew are scheduled to blast off at 7:43 p.m. We'll have live updates from Kennedy Space Center and a full slate of special guests during a countdown broadcast starting later today. Click here to see an early-morning post with a complete schedule of special guests you'll see here today.

Commander Lee Archambault and his six crewmates are bound for the International Space Station on a construction mission. They'll deliver and install the last piece of the station's central truss and a final set of solar arrays, bringing the outpost to full power. Liftoff is set for 7:43 p.m. today.

IMAGE NOTES: The top two images are the latest live shots from the weather channel at the Cape and NASA TV's feed from Pad 39A. The lower image embedded in the text is a screen capture from NASA TV showing the pumps at the launch pad starting to churn, just before the fueling operation began.