Live: Valve not leaking, countdown on track

The gaseous hydrogen valve that prompted Wednesday's launch scrub is not leaking today, so far, and NASA is pressing forward with plans for a 7:43 p.m. liftoff.

More than two hours into the fueling of the space shuttle Discovery, controllers opened the repaired valve and saw no indication of leaks or other problems.

Fueling should continue for almost another hour. So far, the weather remains stable with a few rain clouds out to sea and a stiff breeze. Also, NASA has reported no other technical show-stoppers.

At right, you can see images of the area repaired by crews over the past few days as well as a recent live shot of the shuttle team in the Launch Control Center.

Tonight's launch would send Discovery and seven astronauts on a trip to the International Space Station to install the final piece of the outpost's central truss and a last set of power-producing solar arrays.

Stay with us all day for live updates.