Space shuttle Discovery countdown clock ticking

The countdown clock is ticking for what is now Wednesday's planned launch of space shuttle Discovery.

The countdown began Sunday afternoon at 2 p.m.

On Saturday, crews finished repairing a leak that was discovered last week in one of the shuttle's maneuvering engines.
    
That leak forced NASA to postpone the liftoff, which was originally set for Monday.

NASA could now have to deal with weather concerns, as showers are set to creep back into the forecast later this week.     
    
There is still a 70 percent chance of good weather at launch time.
    
Mission managers held a status briefing at 10 a.m. Sunday.  They said they're not working on any other issues that could prevent a launch.

Liftoff of Discovery's historic flight is set for 3:52 p.m. Wednesday.