Published: Nov 03, 2010 8:58 PM EDT
Updated: Nov 03, 2010 5:58 PM EDT

CAPE CANAVERAL, Fla. (AP) - NASA managers are meeting to decide whether space shuttle Discovery is safe to lift off on its final mission Thursday. The weather, though, is getting worse.

Forecasters on Wednesday said there is now an 80 percent chance that rain or thunderstorms will interfere.

Wednesday's launch attempt was called off 24 hours in advance because of main engine controller trouble. The computerized controller was slow in starting up, then had strange voltage readings.

Mission managers at the Florida launch site will decide whether the problem poses any threat to liftoff. If repairs are needed, the delay could be significant.

Discovery will head to the International Space Station for its last trip into orbit.