According to the NASA website:

"NASA is wrapping up work on Discovery's fuel sensor circuit problem
and now plans to pick up the countdown Saturday, with a launch no
earlier than 10:39 a.m. EDT on Tuesday, July 26."

I'll try to monitor 10780 khz on Monday, July 25 in the hope of
learning which frequencies to tune to during and after the launch. If I
miss the announcement, hopefully someone else will catch it.

Steve