NASA cleared space shuttle Endeavour for a Friday night launch to the international space station, but the weather outlook was not too promising. A cold front was making its way toward Florida on Wednesday and was expected to bring rain and thick clouds by the weekend. Forecasters put the odds of acceptable conditions at 60 percent for the scheduled 7:55 p.m. Friday liftoff and only 40 percent for Saturday. The chance of success goes up dramatically Sunday. “The timing of the front is really going to be the major factor,” said shuttle weather officer Kathy Winters.
