Rain delays space shuttle launch; now set for Fri.

(AP) -- NASA will try again Friday to send Discovery off on its final journey, after a series of postponements for the oldest and most traveled space shuttle.

Just before daybreak Thursday, mission managers called off an afternoon liftoff because of storms.

Rain was pounding the area, and meteorologists said there was little chance the weather would break in time for launch. Indeed, at the planned liftoff time, it was drizzling.

"As crazy luck would have it," the area's monthlong drought ended Thursday, said Pete Nickolenko, assistant launch director.

"It was really very clear today that it just wasn't looking to be our day weather-wise," he said.

On Friday, the weather outlook improves. There is a 60 percent chance that conditions will be acceptable for launch once the cold front passes through, although wind will be a concern.

Managers will meet again early Friday to evaluate the weather. If they feel they have a decent shot, they will give the go-ahead to fuel Discovery. Liftoff on Friday would be at 3:04 p.m.

Discovery already has been delayed by gas leaks and an electrical problem.

The mission to the International Space Station is now running four days late. It will be the final flight for Discovery, which faces a museum retirement as the shuttle program winds down.

Six veteran astronauts are assigned to the 11-day flight. They have been at Kennedy Space Center for the past week, waiting out all the delays.

NASA has until Sunday to launch Discovery, otherwise the shuttle will remain grounded until the beginning of December because of unacceptable solar angles.

It's officially NASA's next-to-last shuttle flight. Endeavour is scheduled to lift off at the end of February. An extra mission may be added in mid-2011, if money is forthcoming.

The White House wants NASA focused on next-generation rockets and spacecraft that could carry astronauts to asteroids and Mars. The plan, for now, also calls for private business to develop rockets capable of carrying astronauts to the space station. Until then, American space travelers will need to hitch rides on Russian Soyuz vessels.

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