After eight large maneuvers and three trim burns since launching last month, NASA's Solar Dynamics Observatory arrived on station in geosynchronous orbit Tuesday.

An Atlas 5 rocket carried the satellite into an elliptical transfer orbit February 11 from its launch pad at Cape Canaveral. Since then, ground controllers carefully boosted SDO toward its operational perch 22,300 miles high.

Although that altitude is shared by the vast array of other satellites used for communications and weather observing, SDO doesn't hover above one spot on the globe like its neighbors. Instead, it drifts 28 degrees north and south of the equator in a figure eight pattern.

SDO remains in constant view of the project's data-receiving antennas in New Mexico that will collect the continual flow of imagery and data from the spacecraft 24 hours a day, 7 days a week.

The craft, which doesn't have onboard recorders, will downlink 1.5 terabytes of solar information straight to the ground every day.

Scientists hope the data from SDO will help them make better predictions of when solar flares and coronal mass ejections will occur. Those events can threaten satellites and astronauts, disrupt communications and upset power grids.

SDO is the first new satellite to be launched under NASA's Living With a Star program that blends the research being conducted about the Sun and the impacts on Earth.

Now that the orbit raising activities have been successfully completed, work to ready the science instruments will be finished. SDO is expected to commence its observations in the coming weeks.

Greeted by blustery weather and deep blue skies, an Atlas 5 rocket soared into space Thursday morning, successfully placing an $848 million satellite on track to probe the sun and unravel its fundamental affects on Earth and society.

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VIDEO: ATLAS 5 ROCKET BLASTS OFF! HI-DEF
VIDEO: SPACEFLIGHT NOW'S VIEW OF THE LAUNCH HI-DEF
VIDEO: LAUNCH REPLAYS: VEHICLE ASSEMBLY BUILDING HI-DEF
VIDEO: LAUNCH REPLAYS: MOUND AT SPACE SHUTTLE PAD HI-DEF
VIDEO: LAUNCH REPLAYS: SPOT WEST OF COMPLEX 41 HI-DEF
VIDEO: LAUNCH REPLAYS: NORTH BEACH TRACKER HI-DEF
VIDEO: LAUNCH REPLAYS: TOWER AT PAD 39AHI-DEF
VIDEO: LAUNCH REPLAYS: UCS 15 TRACKER HI-DEF
VIDEO: LAUNCH REPLAYS: UCS 23 TRACKER HI-DEF
VIDEO: LAUNCH REPLAYS: BANANA CREEK HI-DEF
VIDEO: LAUNCH REPLAYS: PAD CAMERA SOUTH PLAY
VIDEO: LAUNCH REPLAYS: PAD CAMERA EAST PLAY
VIDEO: LAUNCH REPLAYS: PAD UMBILICALS PLAY
VIDEO: LAUNCH REPLAYS: UCS 12 TRACKER PLAY
VIDEO: LAUNCH REPLAYS: VIF CAMERA PLAY

VIDEO: NARRATED PREVIEW OF THE LAUNCH PLAY
VIDEO: WINDS SCRUB FIRST LAUNCH ATTEMPT PLAY | HI-DEF
VIDEO: NARRATED REVIEW OF SDO'S PREPARATIONS PLAY | HI-DEF
VIDEO: NARRATED REVIEW OF ROCKET'S PREPARATIONS PLAY | HI-DEF
VIDEO: ATLAS 5 ROCKET ROLLS TO LAUNCH PAD PLAY | HI-DEF
VIDEO: THE PRE-LAUNCH NEWS CONFERENCE PLAY
VIDEO: MISSION SCIENCE BRIEFING PLAY
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"The 45th Space Wing is pleased to participate with NASA and our mission partners to launch this important solar observatory," said Brig. Gen. Edward L. Bolton, Jr., 45th Space Wing commander at the Cape. "We are proud to support NASA's scientific missions to unlock the secrets of the universe."

SDO's initial activities are going "like clockwork," according to NASA launch director Omar Baez. The satellite has deployed its power-generating solar arrays and achieved the proper orientation after separation from the Centaur rocket motor.

"ULA is extremely proud to be a part of the SDO mission, NASA's first satellite launch of its 'Living with a Star' program," said Mark Wilkins, United Launch Alliance vice president, Atlas Product Line. "This launch culminates years of hard work by our NASA customer and our ULA launch team. It's appropriate that our 100th use of a commercial Atlas Centaur was for a NASA mission since Centaur was originally developed for NASA's lunar program."

T+plus 108 minutes, 52 seconds. SPACECRAFT SEPARATION! The Centaur upper stage has deployed the Solar Dynamics Observatory into orbit follow today's launch from Cape Canaveral.

The NASA spacecraft will stare directly at the Sun continuously for the next decade to observe the star's varying behavior and how it influences life on Earth.

T+plus 108 minutes. Centaur is in the spacecraft deploy position.

T+plus 107 minutes, 30 seconds. The orbit achieved appears right on target.

T+plus 106 minutes, 30 seconds. Centaur is maneuvering itself to the proper orientation for releasing the payload.

T+plus 106 minutes, 6 seconds. MECO 2. Main engine cutoff confirmed. Centaur has completed its second burn.

T+plus 104 minutes, 30 seconds. All vehicle parameters still reported normal.

T+plus 104 minutes. The engine is burning well. This is a planned 3-minute, 14-second firing by the Centaur's single Pratt & Whitney Rocketdyne RL10 engine.

T+plus 102 minutes, 50 seconds. Ignition and full thrust! The Centaur's single RL10 engine has re-ignited to accelerate the payload into the planned deployment orbit.

T+plus 101 minutes, 45 seconds. The fuel and oxider tanks are being pressurized for engine start.

T+plus 100 minutes. Centaur is flying out over the Pacific now.

T+plus 98 minutes, 35 seconds. The rocket is performing its turn to the proper position for the next engine firing.

T+plus 97 minutes. The Centaur is targeting a geosynchronous transfer orbit stretching from 1,555 statute miles at its lowest point to 21,970 statute miles at its highest and inclined 28.5 degrees to the equator.

T+plus 92 minutes, 40 seconds. Now 10 minutes away from Centaur's second engine firing.

T+plus 90 minutes. The vehicle is completing the final roll reversal as planned.

T+plus 84 minutes. Centaur is operating well with good battery voltages and tank pressures. Telemetry from the rocket is being routed back to the Cape via NASA's Tracking and Data Relay Satellite System.

T+plus 75 minutes. The vehicle is soaring above the northern coast of Australia.

High definition video of the Solar Dynamics Observatory's launch is posted for Spaceflight Now+Plus users here.

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T+plus 69 minutes. The upper stage continues in its thermal conditioning roll while quietly coasting in the parking orbit.

T+plus 57 minutes. Bus and battery voltages, tank pressures and other system measurements look good.

T+plus 45 minutes. A map illustrating the rocket's ground tracking during launch can be viewed here.

T+plus 30 minutes. Deployment of the SDO spacecraft to complete today's launch sequence is expected at 12:12 p.m. EST.

T+plus 17 minutes. Centaur's onboard systems are stable in this coast period gets underway.

T+plus 15 minutes, 17 seconds. MECO 1. Centaur's main engine has shut down following its first burn today, achieving a preliminary orbit around Earth. The rocket will coast in this orbit for about 87 minutes before the RL10 engine re-ignites.

T+plus 14 minutes, 20 seconds. Everything looking normal with one minute to go in this burn.

T+plus 14 minutes. RL10 engine parameters still look good.

T+plus 13 minutes, 55 seconds. Orbital velocity has been achieved.

T+plus 13 minutes, 20 seconds. About two minutes are left in this burn of Centaur.

T+plus 12 minutes, 20 seconds. The rocket is performing a planned roll to improve the link with NASA's orbiting Tracking and Data Relay Satellite System.

T+plus 12 minutes. Centaur systems remain in good shape.

T+plus 11 minutes, 40 seconds. The rocket is 1,770 miles downrange and traveling at 15,400 mph.

T+plus 11 minutes. The RL10 continues to perform well, burning liquid hydrogen and liquid oxygen propellants.

T+plus 10 minutes, 20 seconds. All systems reported stable as the Centaur fires to reach an initial Earth orbit.

T+plus 9 minutes, 45 seconds. Centaur is 166 miles in altitude, some 1,350 miles downrange, traveling at 13,900 mph.

T+plus 9 minutes, 40 seconds. The rocket is tracking right down the planned track.

T+plus 8 minutes, 45 seconds. Centaur is 168 miles in altitude, some 1,100 miles downrange, traveling at 13,200 mph.

T+plus 7 minutes, 20 seconds. Now 156 miles in altitude, 830 miles downrange from the launch pad, traveling at 12,500 mph.

T+plus 5 minutes, 30 seconds. Centaur engine readings look good as this burn gets underway.

T+plus 4 minutes, 50 seconds. The two-halves of the Atlas 5 rocket nose cone encapsulating the spacecraft have separated.

T+plus 4 minutes, 40 seconds. Centaur has ignited! The RL10 engine is up and running at full thrust for its first of two planned firings today.

T+plus 4 minutes, 38 seconds. The Atlas 5's Common Core Booster first stage has been jettisoned, and the Centaur upper stage's liquid hydrogen and liquid oxygen systems are being readied for engine start.

T+plus 4 minutes, 17 seconds. BECO. Booster Engine Cutoff is confirmed as the RD-180 powerplant on the first stage completes its burn. Standing by to fire the retro thrusters and separate the spent stage.

T+plus 3 minutes, 25 seconds. The rocket now weighs only a quarter of what it did at liftoff.

T+plus 3 minutes. RD-180 is performing well as the rocket climbs away from the planet.

T+plus 2 minutes, 50 seconds. Reaction control system has been activated.

T+plus 2 minutes. The rocket is 12 miles in altitude, some 11 miles downrange and traveling over 2,300 mph already.

T+plus 1 minutes, 45 seconds. The RD-180 main engine continues to fire normally, burning a mixture of highly refined kerosene and liquid oxygen.

T+plus 80 seconds. Mach 1.

T+plus 60 seconds. One minute into the ascent. It will take an hour and 49 minutes for the two-stage rocket to deploy the SDO satellite into the desired orbit.

T+plus 40 seconds. Thunderous roar from the Atlas. Good engine performance.

T+plus 15 seconds. The vehicle has cleared the towers at Complex 41 on 860,000 pounds of thrust from the RD-180 main engine.

LIFTOFF! Liftoff of the Atlas 5 rocket, raising the crown jewel of NASA's Living With a Star program -- the Solar Dynamics Observatory.

T-minus 20 seconds. "Go Atlas" and "Go Centaur" was just called by launch team during a final status check.

T-minus 40 seconds. Centaur's liquid oxygen and liquid hydrogen tanks are stable at flight pressures.

T-minus 1 minute. Now 60 seconds from launch of the Solar Dynamics Observatory to study the Sun inside and out.

T-minus 90 seconds. The safety system has been armed.

T-minus 1 minute, 50 seconds. Liquid oxygen and liquid hydrogen propellant topping to the Centaur upper stage is being secured.

T-minus 1 minute, 55 seconds. The launch sequencer has been commanded to start.

T-minus 2 minutes. The Atlas first stage and Centaur upper stage are now switching from ground power to internal batteries.

T-minus 2 minutes, 30 seconds. The first stage RP-1 kerosene fuel tank and the liquid oxygen have stepped up to proper flight pressure levels.

T-minus 3 minutes. The Atlas first stage liquid oxygen replenishment is being secured so the tank can be pressurized for launch.

T-minus 3 minutes, 50 seconds. The ground pyrotechnics have been enabled.

T-minus 4 minutes and counting. Clocks have resumed for the final minutes of tonight's countdown to launch the Atlas 5 rocket carrying SDO. Liftoff is set to occur at 10:23 a.m. EST.

Countdown clocks will resume in one minute.

The ULA launch director has given his "go" for today's liftoff.

Polling of the team by Atlas launch conductor just occurred. All systems are reported "go" to continue with the countdown for liftoff at 10:23 a.m. EST.

The Solar Dynamics Observatory nestled inside the nose of the Atlas 5 rocket is switching to internal power for launch.

Here's a look at some stats about today's mission. This will be:

• The 602nd launch for Atlas program since 1957
• The 316th Atlas to occur from Cape Canaveral
• The 20th launch of an Atlas 5 since 2002
• The 18th Atlas 5 to occur from the Cape
• The 12th Atlas 5 under United Launch Alliance
• The 10th Atlas 5 to fly in the 401 configuration
• NASA's fourth use of the Atlas 5 family
• The 1st Atlas launch of 2010

NASA launch director Omar Baez has polled to verify the agency team is ready to proceed with the countdown.

T-minus 4 minutes and holding. The countdown has entered the planned 10-minute hold to give the launch team a chance to review all systems before pressing ahead with liftoff.

The fuel-fill sequence for the first stage main engine has been completed.

The first stage liquid oxygen tank and Centaur's liquid oxygen and liquid hydrogen tanks are reported at flight level.

T-minus 5 minutes. Standing by to go into the final built-in hold.

Weather remains "go" for launch. Winds are blowing just below the limit and the clouds that have rolled overhead aren't violating any of the rules right now.

"A unique milestone associated with this mission is that is represents the 100th launch of a commercial Atlas/Centaur," said Vernon Thorp, United Launch Alliance's program manager for NASA missions.

"Now, Atlas and Centaur have both flown many times before, of course. Atlas was originally developed for the Air Force and has flown 601 times to date, and Centaur has flown 190 times to date. In the 1960s, NASA actually developed the Centaur. It was the first upper stage developed with the lifting power and the accuracy to fly lunar and planetary missions.

"In the late 1980s, the Atlas and Centaur vehicles, in their combined version, were reborn as what we call the commercial program. In July of 1990, we flew the first commercial Atlas/Centaur mission, and by coincidence, that mission was for NASA as well."

Current winds are right at the 20-knot threshold now.

Thirty minutes from liftoff. The countdown clocks are heading to the T-minus 4 minute mark where a planned 10-minute hold will occur. Launch of Atlas 5 remains scheduled for 10:23 a.m. EST.

Today's launch of the Atlas 5 rocket will last nearly two hours from liftoff until deployment of the Solar Dynamics Observatory.

The RD-180 first stage main engine ignites at T-minus 2.7 seconds, shooting a giant cloud of steam from the pad's main exhaust duct while undergoing a check to ensure its vital signs are healthy, leading to liftoff of the 19-story Atlas vehicle at T+plus 1.1 seconds.

The kerosene-fueled first stage will continue to fire until T+plus 4 minutes, 3 seconds. The bronze stage separates about six seconds later, leaving the hydrogen-fueled Centaur upper stage to ignite for a burn lasting nearly 11 minutes that will inject itself and SDO into a preliminary orbit with a high point over 4,250 statute miles, a low point of 109 statute miles and inclination of 28.5 degrees.

Centaur completes its first burn over the central Atlantic Ocean and enters an 87-minute coast over Africa, Madagascar, the southern Indian Ocean and northern coast of Australia.

The Pratt & Whitney Rocketdyne RL10 cryogenic engine then restarts over the western Pacific for a three-minute firing to propel the SDO spacecraft into the targeted geosynchronous transfer orbit stretching from 21,970 statute miles at its highest point, 1,555 statute miles at the low point and inclination of 28.5 degrees to the equator.

Release of the payload from the rocket to complete the launch is expected at T+plus 1 hour and 49 minutes.

The satellite will deploy its power-generating solar arrays and extend the pair of high-speed communications antenna booms, beginning a three-week process to maneuver itself into a circular geostationary orbit. It should be ready for science in about 60 days.

Live streaming video of the launch is available on your iPhone. Check it out!

Current winds at the launch pad are around 19 knots. The redline limit is 20 knots.

Fast-filling of the first stage liquid oxygen tank has been completed. Topping mode is now underway.

The first stage liquid oxygen tank is 90 percent full now.

The liquid hydrogen tank in the Centaur upper stage just reached the 97 percent level. Topping is now beginning.

Now 60 minutes from liftoff. Fueling of the Atlas rocket with cryogenic liquid oxygen and liquid hydrogen is proceeding as planned for a liftoff at 10:23 a.m. EST.

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Centaur's liquid hydrogen tank is 40 percent full. The cryogenic propellant will be consumed with liquid oxygen by the stage's Pratt & Whitney Rocketdyne-made RL10 engine.

The first stage liquid oxygen has reached the 70 percent level.

Chilldown of the liquid hydrogen system has been accomplished. The launch team has received the "go" to begin filling the Centaur upper stage with the supercold fuel.

First stage liquid oxygen tank is 40 percent full thus far. Chilled to Minus-298 degrees F, the liquid oxygen will be used with RP-1 kerosene by the RD-180 main engine on the first stage during the initial four minutes of flight today. The 25,000 gallons of RP-1 were loaded into the rocket earlier.

The spacecraft team is not working any issues and the Solar Dynamics Observatory is "go" for launch.

The Centaur engine chilldown sequence is being initiated.

Upper stage liquid oxygen has reached flight level.

The Centaur liquid oxygen tank reached the 95 percent level. The topping off process is starting now.

The first stage liquid oxygen loading is switching from slow-fill to fast-fill mode.

The chilldown conditioning of liquid hydrogen propellant lines at Complex 41 is starting to prepare the plumbing for transferring the Minus-423 degree F fuel into the rocket. The Centaur holds about 12,680 gallons of the cryogenic propellant.

Now three-quarters full on Centaur liquid oxygen.

The chilldown conditioning of the systems for the first stage liquid oxygen tank have been completed. And a "go" has been given to begin pumping supercold liquid oxygen into the Atlas 5's first stage.

The Common Core Booster stage's liquid oxygen tank is the largest tank to be filled today. It holds 48,860 gallons of cryogenic oxidizer for the RD-180 main engine.

Half of the Centaur liquid oxygen tank has been filled so far.

The Centaur liquid oxygen tank has reached the 20 percent mark.

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Filling of the Centaur upper stage with about 4,150 gallons of liquid oxygen has begun at Cape Canaveral's Complex 41 following the thermal conditioning of the transfer pipes.

The liquid oxygen -- chilled to Minus-298 degrees F -- will be consumed during the launch by the Centaur's single RL10 engine along with liquid hydrogen to be pumped into the stage a little later in the countdown. The Centaur will perform a pair of firings today to send the Solar Dynamics Observatory into geosynchronous transfer orbit.

The Centaur liquid oxygen pad storage area has been prepped. The next step is conditioning the transfer lines, which is now beginning to prepare the plumbing for flowing the cryogenic oxidizer.

T-minus 120 minutes and counting! The launch countdown is continuing on schedule for today's flight of the Atlas 5 rocket with the Solar Dynamics Observatory aboard.

Clocks have one more built-in hold planned at T-minus 4 minutes. That pause will last 10 minutes during which time the final "go" for launch will be given. All remains targeted for liftoff at 10:23 a.m. EST from Cape Canaveral's Complex 41.

In the next couple of minutes, chilldown thermal conditioning of the mobile launch platform upon which the rocket stands will begin. This is meant to ease the shock on equipment when supercold cryogenic propellants start flowing into the rocket.

After briefing his team on procedures before entering into the final two hours of the countdown, the launch conductor at the Atlas Spaceflight Operations Center just held a pre-fueling readiness poll. All console operators reported a "ready" status.

The ULA launch director also voiced his approval for proceeding with the countdown.

Loading of cryogenic liquid oxygen and liquid hydrogen into the Atlas 5 rocket will be getting underway a short time from now.

NASA launch director Omar Baez has polled the agency advisory team and given his "go" to proceed with fueling the Atlas 5 rocket.

Launch pad winds are about 19 knots right now.

Check out the Spaceflight Now+Plus video archive covering the Solar Dynamics Observatory and its Atlas 5 rocket here. We also have a full listing of High Definition video here.

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T-minus 2 hours and holding. The countdown has just entered the first of two planned holds over the course of the morning that will lead to the 10:23 a.m. EST launch of the Atlas rocket. This initial pause lasts 30 minutes, giving the team some margin in the countdown timeline to deal with technical issues or any work that is running behind. The final hold is scheduled to occur at T-minus 4 minutes and will last for 10 minutes.

The Complex 41 pad and the blast danger area have been cleared of all workers for the remainder of the countdown.

Current winds at the launch pad are hovering right around the 20-knot limit for launch as forecast. The weather officer predicts a 40 percent chance of winds being out limits during today's launch window.

No technical issues are being worked in the countdown and the countdown is ticking on schedule toward a liftoff at 10:23 a.m. EST, weather permitting.

The hazard area roadblocks around the launch site's safety perimeter are being established now. And the launch team has started configuring the pad's water deluge system.

Recent activities completed in the countdown have included final preps for the Atlas first stage liquid oxygen system and the Centaur upper stage's liquid hydrogen and liquid oxygen systems, and checks of the rocket's internal batteries.

It is another frigid morning along Florida's Space Coast. Skies are clear but winds remain frisky and the temperatures are bone-chilling. A crescent moon shines as the first hints of dawn are breaking over the horizon

Weather forecasters now predict a 60 percent chance that conditions will permit the Atlas 5 rocket to launch during today's one-hour window opening at 10:23 a.m. EST.

The official outlook includes scattered mid- and high-level clouds, good visibility, north-northwesterly winds from 330 degrees of 16 gusting to 20 knots and a temperature of 45 degrees F.

The winds will be gusting near the limit and there's also a lesser concern for violating the thick cloud rule.

If the launch slips to Friday morning, rain and extensive cloudiness is forecast at the Florida spaceport, dropping the odds of meting the weather rules to just 40 percent.

The countdown begins anew for another attempt to launch the Atlas 5 rocket and NASA's Solar Dynamics Observatory.

The Atlas launch team are beginning to power up the rocket as clocks start ticking down toward a 10:23 a.m. EST liftoff today from Cape Canaveral, Florida.

The SDO payload team, meanwhile, reported for duty at 2 a.m. to start their pre-flight sequences again.

High winds at Cape Canaveral scrubbed today's launch of the Atlas 5 rocket with NASA's Solar Dynamics Observatory, but only after a teasing mission managers by briefly falling within limits before again gusting too strong.

"From the start of the count, they were problematic," NASA assistant launch director Chuck Dovale said.

"They were slightly diminishing as we were heading toward the window and we thought there was a chance they would go below their requirement. What we are talking about is about 20 knots from the northwest direction."

The rocket had a 60-minute period to launch beginning at 10:26 a.m. EST. The unacceptable gusty winds prompted the launch team to hold the countdown clocks at T-minus 4 minutes, eventually rescheduling the liftoff for the last moment of the window at 11:26 a.m. in hopes the wind speed would decrease by then.

As managers and engineers prepared for the last-chance launch time of the day, the winds began to fall and it appeared the Atlas would get to fly after all.

"There was a period of about four minutes just prior to end window where they actually went within spec. Not being completely clairvoyant, we couldn't predict that and we'd already shifted (target launch time) to the end of the window," Dovale said.

"The trend was, as time went on, they were going to get better. So we thought the most prudent move was to go to the end of the window after we didn't make it for a few attempts in the beginning of the window."

But as clocks resumed ticking, the winds spiked again and violated the limit for launch. That triggered a halt to the countdown, leaving the rocket anchored on the launch pad for the day.

"Just as we got into the T-minus 4 and counting, we saw a sample over 20 knots and that automatically kicked us out," Dovale said.

"We gave it our best shot today and we'll come back again tomorrow."

NASA says there is a 40 percent chance of weather preventing launch during tomorrow's window because of cloudy conditions. Winds are expected to diminish.

After safing the rocket, the launch team is beginning drain the cryogenic propellants from the vehicle.

Launch officials are getting a briefing on the weather conditions expected tomorrow.

Tomorrow's launch window extends from 10:23 to 11:23 a.m. EST. A full chart of launch times can be read here.

"The vehicle sensed wind load that was out of tolerance," a NASA spokesman says, causing the flight control redline monitor to stop the countdown.

SCRUB! Time has run out for the winds to subside and allow the Atlas 5 rocket to launch NASA's Solar Dynamics Observatory today.

Flight control detected a redline violation caused by wind loads on the rocket.

HOLD! A cutoff was declared at T-minus 3 minutes, 59 seconds.

T-minus 4 minutes and counting. Clocks have resumed for the final minutes of tonight's countdown to launch the Atlas 5 rocket carrying SDO. Liftoff is set to occur at 11:26 a.m. EST.

After waiting an hour, winds are within limits for launch at last, NASA declares!

Today's launch of the Atlas 5 rocket will last nearly two hours from liftoff until deployment of the Solar Dynamics Observatory.

The RD-180 first stage main engine ignites at T-minus 2.7 seconds, shooting a giant cloud of steam from the pad's main exhaust duct while undergoing a check to ensure its vital signs are healthy, leading to liftoff of the 19-story Atlas vehicle at T+plus 1.1 seconds.

The kerosene-fueled first stage will continue to fire until T+plus 4 minutes, 3 seconds. The bronze stage separates about six seconds later, leaving the hydrogen-fueled Centaur upper stage to ignite for a burn lasting nearly 11 minutes that will inject itself and SDO into a preliminary orbit with a high point over 4,250 statute miles, a low point of 109 statute miles and inclination of 28.5 degrees.

Centaur completes its first burn over the central Atlantic Ocean and enters an 87-minute coast over Africa, Madagascar, the southern Indian Ocean and northern coast of Australia.

The Pratt & Whitney Rocketdyne RL10 cryogenic engine then restarts over the western Pacific for a three-minute firing to propel the SDO spacecraft into the targeted geosynchronous transfer orbit stretching from 21,970 statute miles at its highest point, 1,555 statute miles at the low point and inclination of 28.5 degrees to the equator.

Release of the payload from the rocket to complete the launch is expected at T+plus 1 hour and 49 minutes.

The satellite will deploy its power-generating solar arrays and extend the pair of high-speed communications antenna booms, beginning a three-week process to maneuver itself into a circular geostationary orbit. It should be ready for science in about 60 days.

The ULA launch director has given his "go" for today's liftoff.

Polling of the team by Atlas launch conductor just occurred. All systems are reported "go" to continue with the countdown for liftoff at 11:26 a.m. EST.

Here's a look at some stats about today's mission. This will be:

• The 602nd launch for Atlas program since 1957
• The 316th Atlas to occur from Cape Canaveral
• The 20th launch of an Atlas 5 since 2002
• The 18th Atlas 5 to occur from the Cape
• The 12th Atlas 5 under United Launch Alliance
• The 10th Atlas 5 to fly in the 401 configuration
• NASA's fourth use of the Atlas 5 family
• The 1st Atlas launch of 2010

SDO is being placed on internal power for launch again.

Wind speeds continue to fall. Now 12 minutes away from the scheduled launch time.

NASA launch director Omar Baez reconfirms the agency will be ready when the weather is.

The launch weather officer says the trend he was expecting late in the wind is establishing itself.

Winds at Complex 41 are trending downward. It's just a question if they will come within limits before today's launch window closes at 11:26 a.m. EST.

The Solar Dynamics Observatory is returning to ground-fed power for this extended hold. It will go back to internal power for launch later.

NEW LAUNCH TIME. Liftoff now pushed back to 11:26 a.m., the very last available moment in today's launch window.

NASA launch director Omar Baez has polled the agency team and given his "go" to proceed with the countdown, once the weather improves.

The countdown remains holding at T-minus 4 minutes as the Atlas 5 rocket waits on the winds to decrease for launch today. There are no technical problems being worked, it's just a matter of the weather.

A reminder that if you will be away from your computer but would like to receive occasional countdown updates, sign up for our Twitter feed to get text message updates on your cellphone. U.S. readers can also sign up from their phone by texting "follow spaceflightnow" to 40404. (Standard text messaging charges apply.)

NEW LAUNCH TIME. Liftoff now pushed back to 10:56 a.m., if the winds subside.

An additional 10 minutes have been added to the hold. That puts launch time no earlier than 10:46 a.m. But the winds remain "no go."

HOLD EXTENDED. Officially, launch has been delayed at least 10 minutes due to the winds.

The Solar Dynamics Observatory nestled inside the nose of the Atlas 5 rocket is switching to internal power for launch.

The first stage liquid oxygen tank and Centaur's liquid oxygen and liquid hydrogen tanks are reported at flight level.

T-minus 4 minutes and holding. The countdown has entered the planned 10-minute hold to give the launch team a chance to review all systems before pressing ahead with liftoff.

But the ground winds at Complex 41 remain out of limits. So the clocks will stay stopped at this point in the countdown until the weather improves.

Today's launch opportunity stretches from 10:26 to 11:26 a.m. EST. There is hope the winds would ease later in the window, but it remains to be seen if that will happen.

T-minus 5 minutes. Standing by to go into the final built-in hold.

A peak wind of 32 knots was just recorded at the launch pad. The limit is the low 20s, the exact constraint depends on the specific direction.

The fuel-fill sequence for the first stage main engine is starting.

The liquid hydrogen tank in the Centaur upper stage just reached the 97 percent level. Topping is now beginning.

Thirty minutes from liftoff, if the weather permits. The countdown clocks are heading to the T-minus 4 minute mark where a planned 10-minute hold will occur. Launch of Atlas 5 remains scheduled for 10:26 a.m. EST.

Live streaming video of the launch is available on your iPhone. Check it out!

The Centaur liquid hydrogen tank is half loaded so far. The cryogenic propellant will be consumed with liquid oxygen by the stage's Pratt & Whitney Rocketdyne-made RL10 engine.

Centaur's liquid hydrogen tank is 30 percent full.

Winds at the launch pad remain between 26 and 28 knots, well above the limit.

Fast-filling of the first stage liquid oxygen tank has been completed. Topping mode is now underway.

Chilldown of the liquid hydrogen system has been accomplished. The launch team has received the "go" to begin filling the Centaur upper stage with the supercold fuel.

The first stage liquid oxygen tank is 90 percent full now.

Engineers say the guidance system alignment issue under discussion is being caused by the high winds on the rocket.

Now 60 minutes from liftoff. Fueling of the Atlas rocket is proceeding for a liftoff at 10:26 a.m. EST. But the winds remain very strong.

The troubleshooting team is discussing an alignment issue with the control system.

Upper stage liquid oxygen has reached flight level.

The Centaur liquid oxygen tank reached the 95 percent level. The topping off process is starting now.

The first stage liquid oxygen tank is 50 percent full.

The chilldown conditioning of liquid hydrogen propellant lines at Complex 41 is starting to prepare the plumbing for transferring the Minus-423 degree F fuel into the rocket. The Centaur holds about 13,000 gallons of the cryogenic propellant.

The Centaur liquid oxygen tank is 75 percent full now.

The Centaur engine chilldown sequence is being initiated.

Half of the Centaur liquid oxygen tank has been filled so far.

First stage liquid oxygen tank is about a third full thus far. Chilled to Minus-298 degrees F, the liquid oxygen will be used with RP-1 kerosene by the RD-180 main engine on the first stage during the initial four minutes of flight today. The 25,000 gallons of RP-1 were loaded into the rocket earlier.

The Centaur liquid oxygen tank is nearing one-third full.

The first stage liquid oxygen loading is switching from slow-fill to fast-fill mode.

Filling of the Centaur upper stage with about 4,300 gallons of liquid oxygen has begun at Cape Canaveral's Complex 41 following the thermal conditioning of the transfer pipes.

The liquid oxygen -- chilled to Minus-298 degrees F -- will be consumed during the launch by the Centaur's single RL10 engine along with liquid hydrogen to be pumped into the stage a little later in the countdown. The Centaur will perform a pair of firings today to send the Solar Dynamics Observatory into geosynchronous transfer orbit.

The chilldown conditioning of the systems for the first stage liquid oxygen tank have been completed. And a "go" has been given to begin pumping supercold liquid oxygen into the Atlas 5's first stage.

The Common Core Booster stage's liquid oxygen tank is the largest tank to be filled today. It holds about 50,000 gallons of cryogenic oxidizer for the RD-180 main engine.

The troubleshooting team says the engine purge pressure is in a good configuration now and recommends proceeding onward with the countdown. And with that, the "go" has been given for Centaur liquid oxygen chilldown in preparation for fueling.

When switching back to high-flow on the Centaur engine purge, the pressure readings returned to the expected value.

The launch team will cycle back and forth between low- and high-flow three times to further examine the situation.

As part of troubleshooting, the Centaur engine purge was switched from back to low-flow and the readings appeared normal. It was the high-flow that the pressure measurements were just 4 psi when they should have been about 180 psi.

The launch team will hold off Centaur liquid oxygen loading until this pneumatics issue is understood.

The Centaur pneumatics engineer is reporting unexpected aft purge outlet pressure readings. Instead of 180 psi, he is seeing just 4 psi. The troubleshooting team is convening to assess the situation and a possible valve problem.

T-minus 120 minutes and counting! The launch countdown is continuing on schedule for today's flight of the Atlas 5 rocket with the Solar Dynamics Observatory aboard.

Clocks have one more built-in hold planned at T-minus 4 minutes. That pause will last 10 minutes during which time the final "go" for launch will be given. All remains targeted for liftoff at 10:26 a.m. EST from Cape Canaveral's Complex 41.

In the next couple of minutes, chilldown thermal conditioning of the mobile launch platform upon which the rocket stands will begin. This is meant to ease the shock on equipment when supercold cryogenic propellants start flowing into the rocket.

All console operators in the Atlas Spaceflight Operations Center reported a "ready" status during the pre-fueling poll just completed by the launch conductor. The ULA launch director voiced his approval as well. Loading of cryogenic liquid oxygen and liquid hydrogen into the Atlas 5 rocket will be getting underway a short time from now. Liftoff remains targeted for 10:26 a.m. EST, if the winds subside.

Atlas launch conductor is briefing his team on procedures before entering into the final two hours of the countdown. A readiness check of the team members is next.

NASA launch director Omar Baez has polled the agency advisory team and given his "go" to proceed with fueling the Atlas 5 rocket.

The weather team is hopeful that some lulls in the strong winds will come later in today's launch window.

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T-minus 2 hours and holding. The countdown has just entered the first of two planned holds over the course of the morning that will lead to the 10:26 a.m. EST launch of the Atlas rocket. This initial pause lasts 30 minutes, giving the team some margin in the countdown timeline to deal with technical issues or any work that is running behind. The final hold is scheduled to occur at T-minus 4 minutes and will last for 10 minutes.

The Solar Dynamics Observatory is in good shape and "go" for launch. The spacecraft team is not working any issues.

Workers have cleared the Complex 41 pad and the blast danger area in advance of this morning's propellant loading and launch of the Atlas 5 rocket.

The latest check of the weather shows current conditions are "no go" due to strong winds blowing across the Cape this morning. After peaking at 34 knots an hour ago, the winds are trending downward slightly.

But there's now only a 30 percent chance that winds will be within limits during today's launch window.

The outlook includes some scattered clouds, good visibility, northwesterly winds from 320 degrees of 24 gusting 28 knots and a temperature of 51 degrees F.

The hold-fire checks have been performed to ensure safety officers have the capability of halting the countdown if a problem occurs.

Meanwhile, the official clearing of personnel from the launch pad for rest of the countdown has begun.

The guidance system testing and flight control operational test have been reported complete.

Final preps for the Centaur upper stage's liquid hydrogen and liquid oxygen systems are complete and the helium bottles have been pressurized.

Checks of the rocket's internal batteries are getting underway now.

The countdown is progressing on this blustery morning at the Florida spaceport. Final preps for the Atlas rocket's first stage propulsion system, hydraulics and pneumatics are underway along with testing of the S-band hardware used in relaying data. Work to ready the ground equipment at the launch pad for today's fueling operations is ongoing as well.

The primary concern going into today's countdown has been the forecast for strong winds in the wake of a passing cold front. Maj. Christopher Lovett from the Air Force launch weather office says northwesterly winds from 310 degrees on the compass are expected between 24 and 28 knots. The limit from that particular direction is 23 knots.

"The good news is that the front should clear the area well before (Wednesday) morning. We should experience clearing conditions as we press on through the countdown, and then through the day tomorrow clouds will become less of an issue. However, the winds will remain strong and that's our primary concern at this point for weather."

The wind limits vary by direction, Lovett explained. "If it shifts 20 degrees more towards the west, then the constraint goes up to 30 knots. If it shifts 20 degrees more to the north, then it drops to 20 knots. So it's entirely dependent on the direction, which is continuously changing."

"It's going to be dicey. The winds are expected to remain pretty strong. We're just hoping to get the winds to turn a little more to the west, which would give us more of a break," he said.

With a 60-minute window to get the rocket launch, officials are hopeful there will be an opportunity when the winds will cooperate Wednesday.

"Over an hour period, we would expect some variability in the wind direction. If it varies more to the west, it's good for us. More to the north is bad for us. We're looking for a good solid 10 or 15 minutes or so to get the vehicle off the ground," he said.

The countdown clocks are starting to tick for today's launch of the Solar Dynamics Observatory aboard an Atlas 5 rocket from Cape Canaveral, Florida.

The launch team is beginning to power up the rocket and commence standard pre-flight tests. Over the next few hours, final preps for the Centaur's liquid oxygen and liquid hydrogen systems will be performed, along with a test of the rocket's guidance system and the first stage propulsion and hydraulic preps, internal battery checks and testing of the C-band system used to track the rocket as it flies downrange, plus a test of the S-band telemetry relay system. The Complex 41 site will be cleared of all personnel at 7:30 a.m.

A planned half-hour hold begins at 7:46 a.m. when the count reaches T-minus 120 minutes. Near the end of the hold, the team will be polled at 8:13 a.m. to verify all is in readiness to start fueling the rocket for launch.

Supercold liquid oxygen begins flowing into the Centaur upper stage around 8:33 a.m., followed by the first stage filling around 8:46 a.m. Liquid hydrogen fuel loading for Centaur will be completed a short time later.

A final hold is scheduled at the T-minus 4 minute mark starting at 10:12 a.m. That 10-minute pause will give everyone a chance to finish any late work and assess the status of the rocket, payload, Range and weather before proceeding into the last moments of the countdown for liftoff at 10:26 a.m. EST.

A 60-minute window extends to 11:26 a.m. EST, if an ontime launch isn't possible due to the weather or some other reason.

Check out this gallery of photos by Pat Corkery showing the Atlas 5 rocket rolling out with NASA's Solar Dynamics Observatory.

An Atlas 5 rocket was rolled to its Cape Canaveral pad this morning for Wednesday's launch of the Solar Dynamics Observatory, a NASA spacecraft that will stare directly at the Sun continuously for the next decade to observe the star's behavior and how it influences life on Earth.

Riding atop its mobile launching platform, the United Launch Alliance-built rocket left the Vertical Integration Facility at 8:03 a.m. EST for the 1,800-foot trip along rail tracks to Complex 41.

By 8:39 a.m., the 19-story-tall vehicle had reached the pad and was ready for final pre-flight activities to begin.

Within the next hour, the auto couplers between the pad and platform will be engaged to route umbilical connections from the ground to the rocket for tomorrow's fueling of the booster with cryogenic propellants.

Ground crews will spend a few hours conducting various test sequences and removing the undercarriages used to transport the launch platform before securing the rocket for a quiet evening.

The launch countdown begins Wednesday at 3:26 a.m. EST, leading to blastoff seven hours later at 10:26 a.m. EST. The day's available window to get the rocket airborne extends an hour to 11:26 a.m. EST.

The $848 million Solar Dynamics Observatory mission is the first new satellite to be launched under NASA's Living With a Star program that blends the research being conducted about the Sun and the impacts on Earth.

"Even though to the naked eye the Sun appears to be a constant, pale yellow ball, it is only a limitation of human eyes. The Sun is really not a constant. In fact, modern telescopes and spacecraft have really penetrated the blinding glare of the Sun and have found a maelstrom of unpredictable turmoil," said Madhulika Guhathakurta, the SDO program scientist at NASA Headquarters.

"The origins and fate of life on Earth are intimately connected to the way the Earth responds to the Sun's variations. Recognizing this importance, in 2001 NASA initiated a program called Living With a Star whose goal is to study the Sun as a variable star and its impact on life and society."

Scientists believe data from SDO will help them make better predictions of when solar flares and coronal mass ejections will occur. Those events can threaten satellites and astronauts, disrupt communications and upset power grids.

"While sunlight enables and sustains life, the Sun's variability produces streams of high energy particles and radiation that can harm life and even alter its evolution," Guhathakurta said.

"Understanding solar variability is crucial to our modern way of life."

SDO is headed to geosynchronous orbit 22,300 miles above the equator, in view of the project's data-receiving antennas in New Mexico that will collect the constant flow of imagery and data from the spacecraft 24 hours a day, 7 days a week.

The craft doesn't employ onboard recorders, using a continual downlink to the ground instead. The massive flow of solar information amounts to 1.5 terabytes per day.

We will provide extensive live countdown and launch coverage Wednesday morning right here on this page!

The rocket has entered through the pad gate already.

Meteorologists continue to predict only a 40 percent chance of acceptable weather during Wednesday's launch window due to gusty winds and thick clouds.

"High pressure migrates east as the next frontal boundary enters the Florida panhandle this morning and transits Central Florida this evening through early Wednesday morning. In advance of the front, there is an increasing threat of showers through the day with a small threat of isolated thunderstorms this afternoon and evening," the weather team reported this morning.

"On launch day, a gradual clearing trend is expected behind the front. However, the pressure gradient remains tight with gusty northwest winds persisting through the launch window. The primary concerns for launch day are ground winds and thick clouds."

Rollout begins! The United Launch Alliance Atlas 5 rocket that will deliver NASA's Solar Dynamics Observatory into orbit just began a slow half-hour drive from the 30-story Vertical Integration Facility to Cape Canaveral's Complex 41 pad for Wednesday morning's liftoff.

A pair of specially-made "trackmobiles" are carrying the Atlas 5 rocket's 1.4-million pound mobile launching platform along rail tracks for this third-of-a-mile trip. The two-stage rocket was put together inside the Vertical Integration Facility in December. The payload was mounted atop the vehicle at the end of January.

The Atlas 5 is designed to spend minimal time at the launch pad, which does not include a service gantry like other sites. With liftoff targeted for 10:26 a.m. EST tomorrow, the Atlas will be at the pad only about 26 hours.

The doors on the Vertical Integration Facility are open and the Atlas 5 rocket is ready to emerge for this morning's rollout to Cape Canaveral's Complex 41 launch pad. The move is expected to begin at 8 a.m. EST.

This morning's launch of shuttle Endeavour clears the way for the scheduled Wednesday liftoff of the Atlas 5 rocket with NASA's Solar Dynamics Observatory spacecraft.

But the launch team will be confronted with some weather Wednesday morning. Brisk winds, thick clouds and isolated showers are in the forecast during the Atlas 5's launch window, which opens at 10:26 a.m. EST and extends for one hour. The overall probability of violating launch weather constraints is 60 percent.

Perched atop a mobile platform, the Atlas 5 rocket will roll one-third of a mile from Complex 41's Vertical Integration Facility to the launch pad around 8 a.m. EST Tuesday morning.

A cold front is expected to pass through Central Florida on Tuesday, bringing cooler weather, gusty winds and clouds.

"On launch day (Wednesday), a gradual clearing trend is expected behind the front. However, the pressure gradient remains tight with gusty northwest winds persisting through the launch window. The primary concerns for launch day are ground winds and thick clouds. In the event of a 24-hour delay, the pressure gradient loosens slightly with northwest winds gusting to the 20-knot azimuth constraint. The primary concern for a 24-hour delay is ground winds and thick clouds associated with increasing moisture in advance of the next Gulf system Friday evening," the official Air Force weather forecast says.

According to meteorologists, there will be a layer of scattered stratocumulus clouds between 2,500 feet and 5,000 feet, scattered altostratus clouds between 10,000 feet and 12,000 feet, and scattered cirrus clouds between 28,000 feet and 34,000 feet.

The temperature will be between 50 and 52 degrees F, winds at the 230-foot level will be out of the northwest between 22 and 26 knots, visibility will be 7 miles, and the relative humidity will be 60 percent. Isolated rain showers are also in Wednesday's outlook.

Should launch be pushed back to Thursday, odds of good weather improve to just a 40 percent chance of weather being out of limits.

Today's scrub of shuttle Endeavour means Tuesday's planned launch of the Atlas 5 rocket carrying the Solar Dynamics Observatory from nearby Complex 41 at Cape Canaveral will be pushed back 24 hours too.

The Eastern Range needs two days between launches of different vehicles to reset its tracking, safety and communications systems. So Endeavour's delay ripples to the Atlas.

A Wednesday launch of the Atlas would occur during a window extending from 10:26 to 11:26 a.m. EST.

Assuming the space shuttle Endeavour launches from the Kennedy Space Center on Sunday as scheduled, an Atlas 5 rocket will get its shot to fly from Cape Canaveral on Tuesday morning carrying the Solar Dynamics Observatory.

The Air Force-controlled Eastern Range that provides tracking, communications and safety services for all launches at the Florida spaceport needs about 48 hours to reconfigure equipment to support a different vehicle.

Endeavour has three launch opportunities reserved on the Range for Sunday, Monday and Tuesday. The Atlas liftoff will follow two days later, whenever the shuttle gets off in its window.

You can follow along with Endeavour's launch countdown and flight in our Mission Status Center.

Managers working on the Atlas launch held their Flight Readiness Review on Friday and reported that all preparations are progressing smoothly. An earlier concern related to the first stage main engine has been resolved without impacting the schedule.

Inside the Vertical Integration Facility hangar at the Cape's Complex 41, the Solar Dynamics Observatory payload team has completed its testing sequence and buttoned up the spacecraft for flight. The rocket's ordnance was connected Friday.

The next milestone occurs Sunday when the Launch Readiness Review will be held. That meeting gives approval to transport the rocket from the assembly building to the launch pad and begin the final countdown.

Rollout is targeted for 8 a.m. EST on Monday. Air Force meteorologists expect fair weather and no threat of lightning during the rocket's stay on the pad.

Tuesday's 60-minute launch window opens at 10:30 a.m. EST, and the early weather forecast predicts an 80 percent chance of acceptable conditions.

"On launch day, high pressure migrates east as the next low pressure system with trailing cold front encroaches into the Gulf Coast states. There is a small threat of isolated showers during the count," forecasters say.

The launch time outlook includes some scattered low- and high-level clouds, good visibility, southeasterly winds of 12 to 16 knots and a temperature around 66 degrees F.

The only concern will be violating the cumulus cloud constraints.

If the launch should slip to Wednesday morning, the odds of acceptable weather decrease to 60 percent due to potential problems with cumulus clouds and cloud thickness.

"In the event of a 24-hour delay, the aforementioned cold front is expected to be over Central Florida during the count with increasing cloud cover and isolated showers. Winds are expected to be from the west gusting in the upper teens to 20 knots," forecasters say.

The spacecraft NASA is calling the "crown jewel" mission for probing solar physics was delivered to a Cape Canaveral rocket assembly building and mounted aboard its launcher Tuesday morning.

The Solar Dynamics Observatory had spent the past six months at the Astrotech complex in Titusville being readied for flight. Last week, the satellite was enclosed in the two-piece nose cone and set aboard the transportation trailer for its trip to join the Atlas 5 rocket.

Managers met Monday and gave formal approval to proceed with SDO's attachment to the launch vehicle. Officials determined that the continuing efforts to clear a concern with the rocket's main engine would not impede Tuesday's milestone move.

In the early morning hours Tuesday, the satellite was trucked across the Kennedy Space Center to Complex 41's Vertical Integration Facility at the Cape where the Atlas stood stacked on a mobile launching platform. The trip began at 12:50 a.m. EST and took about four hours, NASA said.

By 8 a.m., cranes started hoisting the 6,800-pound spacecraft into the building through the open doorway and gently maneuvering SDO into place atop the Centaur upper stage.

Launch of the Atlas 5 rocket remains targeted for February 9 at 10:30 a.m. EST. Between now and then, a final round of checks will be performed to ensure SDO is in perfect shape for its mission. Also, a combined test for the rocket and its payload will be conducted to verify systems are operating in synch for ascent.

Also upcoming is the review process to give the "go" for sending the Atlas 5 and SDO into space. The Flight Readiness Review is scheduled for Friday, February 5 to assess the status of preparations. That meeting will be followed by the Launch Readiness Review on Sunday, February 7, culminating in clearance for rolling the rocket out to the launch pad and beginning the countdown on Monday, February 8.

Details of the engine issue remain out of the public realm because of the foreign-made hardware involved. Officials are working to make certain that a problem on a different Russian engine has no impact on the successful use of the powerplant installed on SDO's rocket. NASA says the concern might not be put to rest until the FRR late next week.

The other wild card for making SDO's launch date is the space shuttle Endeavour, which is slated for blastoff from nearby pad 39A on Sunday, February 7. The Air Force-run Eastern Range at the Cape needs about 48 hours between flights of different space vehicles to reconfigure tracking, safety and communications systems from one launch to another. Any scrubs in Endeavour's launch would delay SDO accordingly.

The Atlas launch sequence will last an hour and 49 minutes from liftoff until deployment of SDO from the Centaur upper stage. The craft will be released into a highly elliptical geosynchronous transfer orbit with a high point of 21,970 statute miles, low point of 1,555 statute miles and inclination of 28.5 degrees.

In the subsequent weeks, SDO's own propulsion system will circularize the orbit to approximately 22,300 miles over the equator in view of its ground station in New Mexico. Since the inclination will be left at 28.5 degrees, the satellite's motion in the sky will appear as a "figure eight" pattern.

If all goes well, full science observations should begin about 60 days after launch and last at least five years.

"It will observe the Sun faster, deeper and in greater detail than any previous observations, breaking barriers of time, scale and clarity that have long blocked progress in solar physics," said Madhulika Guhathakurta, the SDO program scientist at NASA Headquarters.

"It is going to revolutionize our view of the Sun and it will reveal how solar activity affects our planets and helps us anticipate what lies ahead."

At a satellite-readying hangar outside the Kennedy Space Center on Thursday, NASA's sophisticated new Sun-studying probe was enclosed within the giant metal fairing that will shroud the craft during ascent to space atop an Atlas 5 booster next month.

The Solar Dynamics Observatory is being prepared for launch from the Cape's Complex 41 on February 9 during a one-hour window opening at 10:30 a.m. EST (1530 GMT).

"We're excitedly nervous. We're nervously excited. It has been a long time. This mission started back in 2001. We've been ready for over a year to launch. We're ready," Dean Pesnell, the SDO project scientist, said during an interview inside the satellite cleanroom Thursday.

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