Preparations for launch of NASA’s Mars Science Laboratory aboard an unmanned Atlas 5 rocket are on schedule for 10:02 a.m. EST this morning.

It’s bit cloudy at the Cape Canaveral launch site — actually drizzling as NASA’s launch commentary started up at 7:30 a.m. — but skies are expected to clear. Meteorologists are predicting a 70 percent chance the weather will be suitable for launch sometime during this morning’s one hour, 43 minute window.

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Workers have cleared the launch pad to prepare for the hazardous operation of fueling the rocket with liquid oxygen in the first stage and liquid oxygen and liquid hydrogen in the Centaur upper-stage motor.

"At this point everything is continuing to go well," said NASA spokesman George Diller.


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Mars Science Lab, nicknamed "Curiosity," is a $2.5 billion nuclear-powered rover that is about size of a compact car — about twice as long and three times heavier than NASA’s predecessor Mars rovers, Spirit and Opportunity.

Curiosity is expected to touch down on Aug. 6, 2012, inside a 96-mile-wide impact crater called Gale Crater to scout for chemicals and geologic environments that may have been suited for life.

Update: 9:15 a.m. 

The Atlas rocket has been fueled and all remains on schedule for launch at 10:02 a.m. EST. So far, the weather appears to be cooperating.

Image: Mars Science Lab's rocket ride to space, an Atlas 5 booster, is poised for blastoff at 10:02 a.m. EST Saturday from Cape Canaveral Air Force Station in Florida. Credit: United Launch Alliance.

Update: 9:58 a.m.

Launch team has cleared the rocket for blastoff at 10:02