This story was updated at 8:46 a.m. EDT.
CAPE CANAVERAL, Fla. ? CAPE CANAVERAL, Fla. ? Stormy weather forced NASA to delay the launch of the space shuttle Discovery for at least one more day, the latest in a string of setbacks for what will be the spacecraft's final mission.
Discovery was slated to blast off from a seaside pad here at the Kennedy Space Center at 3:29 p.m. EDT (1929 GMT), but persistent rain in the area, and a gloomy outlook that called for an 80 percent chance of stormy weather, convinced NASA officials to stand down for the day.
"If it looked like there was any possible chance of giving it a shot, then I think we would have chosen to proceed with tanking," said Pete Nickolenko, NASA's assistant shuttle launch director. "But, it was really very clear today that it wasn't looking to be our day weather-wise."
Even though shuttle technicians can fill the orbiter's external fuel tank in the rain, clearer conditions are required for launch and for safety precautions in the event of an emergency Return To Launch Site (RTLS) abort situation. [GRAPHIC: NASA's Space Shuttle ? From Top to Bottom]
"The launch forecast continues to be poor, with solid rain showers forecasted for throughout the day," Nickolenko said. "The team concluded it was not prudent to pick up with tanking today. So, at this point, we're going to be inserting a 24-hour delay in our countdown procedures."
The shuttle is now slated to launch no earlier than Friday, Nov. 5 at 3:04 p.m. EDT (1904 GMT). Discovery's launch time moves up earlier each day to keep the shuttle on target to meet its destination ? the International Space Station ? two days after liftoff.
Weather assessments for Friday show a significant improvement, with current forecasts projecting a 60 percent chance of acceptable launch conditions. The main concern, however, will be winds around the launch site.
"We'll be watching winds tomorrow, and see what launch wind and headwind issues may be ? if any ? for us," Nickolenko said. "I fully expect that the team should be ready to give it a shot tomorrow."
Top mission managers will meet again tomorrow at 5 a.m. EDT (0900 GMT) to reassess the weather situation.
Today's weather delay comes after several other hurdles prevented Discovery from launching into space on Monday (Nov. 1) as originally planned. Two minor gas leaks forced a two-day delay to allow time for repairs. Then, an electrical glitch in a backup computer for one of the shuttle's three main engines was discovered Tuesday, adding another day of delay.
Discovery's final mission will deliver critical spare parts to the station, as well as a storage room module and a humanoid robot to assist the crew of the orbiting laboratory.
The flight will mark Discovery's 39th trip to space and NASA's 133rd shuttle flight as the agency prepares its three-orbiter fleet to retire in 2011. Discovery will be the first of NASA's shuttles to be retired when it returns to Earth after this mission.
The shuttle's six-astronaut STS-133 crew is made up of commander Steve Lindsey, pilot Eric Boe, and mission specialists Alvin Drew, Tim Kopra, Michael Barratt and Nicole Stott. All are veteran astronauts making return trips to the space station.
Discovery's 11-day mission will include two spacewalks, during which mission specialists Drew and Kopra will perform maintenance tasks on the exterior of the station.
- 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 @denisechow as she covers Discovery's final space voyage from Cape Canaveral, Fla. Click here for mission updates, new stories and a link to NASA's live webcast coverage.