CAPE CANAVERAL, Fla. NASA engineers are working to understand a last-minute electrical glitch on the space shuttle Discovery and eyeing dismal weather forecasts for its planned launch on Thursday.
Discovery is slated to lift off on its final flight no earlier than tomorrow (Nov. 4) at 3:29 p.m. (1929 GMT) from NASA's Kennedy Space Center here, but weather and issues with a backup engine computer on the orbiter could thwart those plans.
Officials delayed the liftoff to Thursday due to an electrical glitch in a backup computer controller in one of Discovery's main engines, which engineers discovered yesterday (Nov. 2).
The malfunction forced NASA to push back Discovery's already delayed launch by at least another day. Earlier this week, the flight was pushed back because of unrelated issues in the spacecraft's aft orbital maneuvering system. [ GRAPHIC: NASA's Space Shuttle From Top to Bottom ]
Even if NASA settles the electrical issue on Discovery in time for a Thursday launch, the weather outlook is not promising.
There is an 80 percent chance that foul weather will cause yet another launch delay for the space shuttle, according to Kathy Winters, NASA's shuttle weather officer.
Discovery's mission management team will meet today at 2 p.m. EDT (1800 GMT) to review the available data and decide whether to fly the shuttle as is, or delay further to troubleshoot and make repairs, said Mike Moses, NASA's shuttle integration manager.
"We fly with known risks, not unknown risks," Moses said late yesterday. "Right now this risk is a little bit unknown."
Discovery is slated to fly an 11-day mission to the International Space Station to deliver a new storage module and a humanoid robot for the orbiting lab's crew. It will be the 39th and last flight for space shuttle Discovery, which is the first of NASA's three shuttles to be retired as the agency winds down its orbiter program next year.
If NASA cannot launch Discovery by Sunday, Nov. 7, it will miss the current window and have to stand down until Dec. 1 to try again.
- GRAPHIC: NASA's Space Shuttle From Top to Bottom
- Gallery: Building Space Shuttle Discovery
- Video Space Shuttle Discovery: A Retrospective, Part 2, Part 3
Follow SPACE.com Staff Writer Denise Chow on Twitter as she covers Discovery's final space voyage from Cape Canaveral, Fla. for mission updates, new stories and a link to NASA's live webcast coverage.