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George Diller/Launch Commentator: This is Atlas Launch Control at T-2 hours and holding.

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We're in a planned built-in hold at this time on the launch of the Juno spacecraft aboard an Atlas V rocket.

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We are now two hours, 32 minutes, 32 seconds away from the liftoff of the Atlas V.

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Liftoff is from Launch Complex 41 at Cape Canaveral.

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The Juno spacecraft will provide the most detailed observations to date of Jupiter,

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the solar system's largest planet.

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Additionally, as Jupiter was most likely the first planet to form,

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Juno's findings will shed light on the history and evolution of the entire solar system.

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The launch window today extends from 11:34 a.m. to 12:43 p.m. EDT, a duration of 69 minutes.

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Following a five-year cruise to Jupiter, which will include a gravity assist Earth flyby,

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Juno will enter into a polar orbit around the planet,

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completing 33 orbits during its science phase before being commanded to

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enter Jupiter's atmosphere to complete the mission.

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Juno will orbit the planet every 11 days, coming as close as 3,100 miles to Jupiter's

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cloud tops while measuring magnetic and gravity fields,

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atmospheric composition, and performing infrared, ultraviolet and visible light photography.

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The Juno spacecraft is unique in several ways.

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It's the first solar-powered spacecraft to perform operations this far from the sun.

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To accomplish this, Juno is equipped with three very large solar arrays,

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which, when extended, bring the spacecraft to a total diameter of 66 feet.

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To combat its exposure to radiation during its year-long orbit of Jupiter,

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most of Juno's electronics have been housed inside a titanium vault in the center of the spacecraft.

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Juno will be spin stabilized throughout its mission in order to maximize the scientific observations.

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We've had a weather forecast from our Launch Weather Officer Clay Flinn and forecast is essentially

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unchanged from what we've been watching all week.

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There is just a 30 percent chance of not meeting the launch weather criteria.

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There will be a chance for some isolated showers, winds will be out of the southeast at around 12