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VIDEO: THE FULL LAUNCH EXPERIENCE PLAY
VIDEO: LAUNCH OF STEREO ABOARD DELTA 2 ROCKET PLAY
VIDEO: POST-FLIGHT REPORT FROM LAUNCH MANAGER PLAY
VIDEO: LAUNCH DAY ROLLBACK OF PAD'S SERVICE TOWER PLAY
VIDEO: NARRATED MOVIE OF DELTA ROCKET PRE-LAUNCH FLOW PLAY
VIDEO: NARRATED MOVIE OF STEREO PRE-LAUNCH PROCESSING PLAY

VIDEO: STEREO PRE-LAUNCH NEWS BRIEFING DIAL-UP | BROADBAND
VIDEO: MISSION SCIENCE PREVIEW DIAL-UP | BROADBAND
VIDEO: DELTA ROCKET'S NOSE CONE INSTALLED FOR LAUNCH PLAY
VIDEO: SATELLITES SEEN MOUNTED ATOP ROCKET PLAY
VIDEO: SPACECRAFT DELIVERED TO LAUNCH PAD PLAY
MORE: STEREO VIDEO COVERAGE
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THURSDAY, OCTOBER 26, 2006

NASA launched a pair of compact spacecraft Wednesday night that will use the moon's gravity to whip them into orbital positions ahead of and behind the Earth to study titanic solar eruptions in 3-D.

Read our launch story.

A gallery of images from tower rollback is posted here. Launch photos can be found here.

The official launch time was 8:52:00.339 p.m. EDT. The flight extended the Delta 2 rocket's string of consecutive successful launches to 69 dating back to 1997. The workhorse launcher has 122 successes in its 124-flight history.

"STEREO is another exciting mission for NASA to help them gain a better understanding of our universe," said Dan Collins, vice president and general manager, Boeing Launch Systems. "Our Delta team takes tremendous pride in our work, and we are extremely pleased to help NASA reach its goals."

The next Delta 2 rocket to launch from the Cape is stacked atop pad 17A, just next door to pad 17B where STEREO lifted off. The upcoming mission is scheduled for November 14 to deploy another replacement satellite for the Global Positioning System.

NASA's next Delta 2 flight is targeted for mid-February from the Cape to loft five tiny satellites to probe Earth's magnetosphere.

0242 GMT (10:42 p.m. EDT Wed.)

The STEREO spacecraft are alive and talking to ground controllers following launch tonight.

The first signals from the craft were received approximately 63 minutes after liftoff via the tracking station in Canberra, Australia. Mission Control at the Johns Hopkins University Applied Physics Laboratory in Maryland report each observatory's solar arrays successfully deployed.

0127 GMT (9:27 p.m. EDT Wed.)

NASA launch manager Omar Baez says tonight's mission has gone very well.

0118 GMT (9:18 p.m. EDT Wed.)

About two minutes after release from the third stage, the twin STEREO spacecraft will separate apart. That is followed two minutes later by deployment of the inboard power-generating solar panels on the craft, then another two minutes later by the outboard panels.

Ground controllers expect to establish first communications with the observatories in about an hour through the Deep Space Network tracking station in Canberra, Australia. That contact will confirm the craft have completed these initial post-launch activities.

So we will pause our live updates for now. Check back around 10:45 p.m. for news on the spacecraft state of health.

0117 GMT (9:17 p.m. EDT Wed.)

T+plus 25 minutes, 11 seconds. SPACECRAFT SEPARATION! The STEREO observatories have been released from the rocket to conclude tonight's launch of the Boeing Delta vehicle from Cape Canaveral.

0116 GMT (9:16 p.m. EDT Wed.)

T+plus 24 minutes. The SECO 2 orbit after the second stage's second burn was right on the money with a high point of 1716.4 miles, perigee of 89.76 miles and inclination of 28.49 degrees. The third stage then boosted STEREO into the deploy orbit stretching to the moon.

0114 GMT (9:14 p.m. EDT Wed.)

T+plus 22 minutes. Three minutes until release of the STEREO spacecraft from the launch vehicle.

0112 GMT (9:12 p.m. EDT Wed.)

T+plus 20 minutes, 5 seconds. Burnout. The third stage has consumed its solid propellant, completing the powered phase of tonight's launch.

0111 GMT (9:11 p.m. EDT Wed.)

T+plus 19 minutes, 30 seconds. The Thiokol Star 48B stage is burning as planned to propel the STEREO spacecraft into a highly elliptical orbit stretching outward to the moon.

0110 GMT (9:10 p.m. EDT Wed.)

T+plus 18 minutes, 55 seconds. Ignition of the solid-fuel third stage motor.

0110 GMT (9:10 p.m. EDT Wed.)

T+plus 18 minutes. Third stage separation confirmed. It is flying free of the spent second stage.

0109 GMT (9:09 p.m. EDT Wed.)

T+plus 17 minutes, 58 seconds. Spinup of the third stage to nearly 60 rpm has started.

0109 GMT (9:09 p.m. EDT Wed.)

T+plus 17 minutes, 20 seconds. SECO 2. The second stage has completed its second burn of this launch. In the next minute, tiny thrusters on the side of the rocket will be fired to spin up the vehicle in preparation for jettison of the second stage.

0108 GMT (9:08 p.m. EDT Wed.)

T+plus 16 minutes, 30 seconds. Burn continues in progress.

0107 GMT (9:07 p.m. EDT Wed.)

T+plus 15 minutes, 39 seconds. Second stage ignition! The motor has restarted for a burn to raise the orbit's high point.

0106 GMT (9:06 p.m. EDT Wed.)

T+plus 14 minutes. As this coast phase of the launch continues, you can see a map of the rocket's planned track here.

0104 GMT (9:04 p.m. EDT Wed.)

T+plus 12 minutes, 45 seconds. The vehicle just passed out of range from the Antigua Island tracking site. There will be a brief telemetry blackout period until the next station acquires. That will be the Cape Verde station off the west coast of Africa.

0103 GMT (9:03 p.m. EDT Wed.)

T+plus 11 minutes, 45 seconds. The rocket has successfully achieved a parking orbit with an apogee of 89.997 miles, perigee of 89.31 miles and inclination of 28.47 degrees. That is right on the pre-planned orbit parameters.

0102 GMT (9:02 p.m. EDT Wed.)

T+plus 10 minutes, 20 seconds. SECO 1. The second stage engine cutoff has occurred, completing the motor's first firing of the day. The Delta 2 rocket with STEREO has arrived in a preliminary orbit around Earth. The vehicle will coast for about five minutes before the second stage is re-ignited to raise the orbit higher.

0101 GMT (9:01 p.m. EDT Wed.)

T+plus 9 minutes, 55 seconds. The speed has increased to 16,500 mph.

0101 GMT (9:01 p.m. EDT Wed.)

T+plus 9 minutes, 30 seconds. The second stage engine is still firing, consuming a hydrazine propellant mixture and nitrogen tetroxide oxidizer. This burn is needed to achieve a parking orbit around Earth.

0101 GMT (9:01 p.m. EDT Wed.)

T+plus 9 minutes. Now 93.5 miles in altitude, 1,180 miles downrange from the launch pad, traveling at 15,750 mph.

0100 GMT (9:00 p.m. EDT Wed.)

T+plus 8 minutes. The Delta 2 rocket is 92.5 miles in altitude, 965 miles downrange from the launch pad, traveling at 14,900 mph.

0058 GMT (8:58 p.m. EDT Wed.)

T+plus 6 minutes, 45 seconds. The downrange tracking station on Antigua Island has picked up the rocket's signal. This Air Force site will cover the rocket's arrival in orbit over the next few minutes. Coverage to this point in the mission has been provided by the TEL-4 station at the Cape.

0058 GMT (8:58 p.m. EDT Wed.)

T+plus 6 minutes, 30 seconds. Good chamber pressure reported on the second stage engine.

0058 GMT (8:58 p.m. EDT Wed.)

T+plus 6 minutes. The vehicle is 80 miles in altitude and traveling more than 13,000 mph.

0057 GMT (8:57 p.m. EDT Wed.)

T+plus 5 minutes. The rocket's nose cone enclosing the spacecraft has been jettisoned. The 10-foot diameter composite shroud separated in two halves now that the vehicle has ascended out of the atmosphere.

0056 GMT (8:56 p.m. EDT Wed.)

T+plus 4 minutes, 52 seconds. Ignition of the the second stage! The Aerojet AJ118-K powerplant has begun the first of its two firings tonight needed to place the upper third stage and STEREO payload into the proper orbit.

0056 GMT (8:56 p.m. EDT Wed.)

T+plus 4 minutes, 46 seconds. The teal-blue first stage has been jettisoned to fall into the Atlantic Ocean below. Standing by for second stage engine start.

0056 GMT (8:56 p.m. EDT Wed.)

T+plus 4 minutes, 36 seconds. Main engine cutoff is confirmed on the first stage.

0056 GMT (8:56 p.m. EDT Wed.)

T+plus 4 minutes. Coming up on first stage engine cutoff.

0055 GMT (8:55 p.m. EDT Wed.)

T+plus 3 minutes, 50 seconds. The vheicle is now 50 miles in altitude, 185 miles downrange from the launch pad and traveling over 8,500 mph.

0055 GMT (8:55 p.m. EDT Wed.)

T+plus 3 minutes, 30 seconds. The main engine is still firing normally, burning its 10,000 gallons of kerosene fuel and 14,700 gallons of liquid oxygen. The rocket is 47 miles in altitude, 203 miles downrange from the launch pad and traveling at 9,100 mph.

0055 GMT (8:55 p.m. EDT Wed.)

T+plus 3 minutes. Delta 319 is 36 miles in altitude, 100 miles downrange from the launch pad and traveling over 6,000 mph.

0054 GMT (8:54 p.m. EDT Wed.)

T+plus 2 minutes, 20 seconds. The three air-ignited solid rocket boosters have burned out and separated. The rocket is now flying solely on the power generated by the liquid-fueled first stage main engine.

0053 GMT (8:53 p.m. EDT Wed.)

T+plus 1 minute, 45 seconds. The air-lit boosters are burning well. The vehicle is 14 miles in altitude, 32 miles downrange from the launch pad and traveling at 3,000 mph.

0053 GMT (8:53 p.m. EDT Wed.)

T+plus 1 minute, 15 seconds. All six ground-start solid rocket boosters have burned out of propellant and separated from the Delta 2's first stage. A moment before the jettison occurred, the three remaining motors strapped to rocket ignited to continue assisting the rocket's RS-27A main engine on the push to space.

0052 GMT (8:52 p.m. EDT Wed.)

T+plus 55 seconds. The Delta 2 rocket has passed through the region of maximum aerodynamic pressure during its atmospheric ascent.

0052 GMT (8:52 p.m. EDT Wed.)

T+plus 40 seconds. The vehicle has broken the sound barrier.

0052 GMT (8:52 p.m. EDT Wed.)

T+plus 30 seconds. The six solid rocket motors ignited on the launch pad have surpassed their period of maximum thrust. Each of the Alliant Techsystems-made boosters generate roughly 100,000 pounds of thrust.

0052 GMT (8:52 p.m. EDT Wed.)

T+plus 20 seconds. The rocket is climbing out of Cape Canaveral on a pillar of blinding fire produced by the main engine and six ground-lit SRBs.

0052 GMT (8:52 p.m. EDT Wed.)

LIFTOFF! Liftoff of the STEREO observatories to change the way we view the sun. And the Delta rocket has cleared the tower!

0051 GMT (8:51 p.m. EDT Wed.)

T-minus 30 seconds. SRB ignitors will be armed at T-minus 11 seconds.

The launch ignition sequence will begin in the final two seconds of the countdown when a Boeing engineer pushes the engine start switch. The process begins with ignition of the two vernier engines and first stage main engine start. The six ground-lit solid rocket motors then light at T-0 for liftoff.

0051 GMT (8:51 p.m. EDT Wed.)

T-minus 1 minute. The Delta 2 rocket's second stage hydraulic pump has gone to internal power after its pressures were verified acceptable.

0050 GMT (8:50 p.m. EDT Wed.)

T-minus 75 seconds. The Air Force's Eastern Range has given the all-clear to launch.

0050 GMT (8:50 p.m. EDT Wed.)

T-minus 100 seconds. First stage LOX topping to 100 percent is underway.

0050 GMT (8:50 p.m. EDT Wed.)

T-minus 2 minutes. Pressurization of the first stage liquid oxygen is now beginning. Puffs of vapor from a relief valve on the rocket will be seen in the remainder of the countdown as the tank pressure stabilizes.

0049 GMT (8:49 p.m. EDT Wed.)

T-minus 2 minutes, 30 seconds. The STEREO spacecraft has been declared "go" for launch.

0049 GMT (8:49 p.m. EDT Wed.)

T-minus 3 minutes and counting. The rocket's third stage safe and arm devices are being armed.

0048 GMT (8:48 p.m. EDT Wed.)

T-minus 3 minutes, 45 seconds. The Delta 2 rocket's systems are now transferring to internal power for launch.

0048 GMT (8:48 p.m. EDT Wed.)

T-minus 4 minutes and counting to launch of the STEREO spacecraft to observe the sun in a new dimension. The Delta 2 rocket is being prepared for liftoff at 8:52 p.m. EDT from pad 17B at Cape Canaveral Air Force Station in Florida.

0047 GMT (8:47 p.m. EDT Wed.)

Standing by to resume the countdown in one minute.

0045 GMT (8:45 p.m. EDT Wed.)

There won't be any additional time to deal with problems. So if the countdown is forced to hold again, launch will be scrubbed for the night. But right now all looks good for liftoff at 8:52 p.m.

0043 GMT (8:43 p.m. EDT Wed.)

The Range is "go" for launch! The countdown will resume at 8:48 p.m. for liftoff of STEREO at 8:52 p.m. EDT tonight.

0041 GMT (8:41 p.m. EDT Wed.)

The STEREO spacecraft has been confirmed on internal power and configured for launch.

0038 GMT (8:38 p.m. EDT Wed.)

Tonight's window to launch the STEREO spacecraft has opened. However, the countdown is holding at T-minus 4 minutes because Range Safety is "no go." The concern is the possibility of toxics from a launch explosion could drift over populated areas given the wind direction and speed tonight.

0035 GMT (8:35 p.m. EDT Wed.)

The nitrogen bottle temperature has warmed and that issue is resolved. But the Range is still "no go."

0034 GMT (8:34 p.m. EDT Wed.)

NEW LAUNCH TIME. The new target liftoff time is 8:52 p.m. EDT.

0033 GMT (8:33 p.m. EDT Wed.)

DELAY. The countdown will not resume as scheduled. So liftoff will be delayed a few minutes tonight, at least.

0033 GMT (8:33 p.m. EDT Wed.)

The STEREO spacecraft cargo atop the Delta 2 rocket is now switching to internal power for launch.

0031 GMT (8:31 p.m. EDT Wed.)

The Range remains "no go" for toxics at this time and the first stage nitrogen bottle is still too cold. Officials and engineers are racing to resolve both problems so that the Delta rocket can fly tonight. Liftoff must occur between 8:38 and 8:53 p.m., otherwise the mission will have to wait until tomorrow night.

0029 GMT (8:29 p.m. EDT Wed.)

Launch team polling is underway.

0028 GMT (8:28 p.m. EDT Wed.)

NASA launch manager Omar Baez says the Range is trying to move people out of the Port Canaveral area so that the toxics won't be a constraint to liftoff tonight. If the Range is successful, launch could still occur at 8:38 p.m. The other option is delaying launch to the end of tonight's window to give the Range more time.

0024 GMT (8:24 p.m. EDT Wed.)

T-minus 4 minutes and holding. The countdown has entered the final planned hold point for this evening's launch attempt. During this planned 10-minute hold, officials will poll the various team members in the soft blockhouse, Range Operations Control Center and Mission Directors Center.

The main hurdle will be Range Safety and its final determination if the toxics situation would threaten the public tonight. And a technical issue is being worked by the launch team to warm up the nitrogen bottle on the first stage that are too cold right now. That warming could itself force a launch delay by a few minutes.

0019 GMT (8:19 p.m. EDT Wed.)

The first stage kerosene fuel tank is being pressurized for launch.

0018 GMT (8:18 p.m. EDT Wed.)

The Range currently stands "no go" for launch. The concern is the possibility of toxics from a launch explosion could drift over populated areas given the wind direction and speed tonight. Safety officials continue to analyze the situation.

0013 GMT (8:13 p.m. EDT Wed.)

T-minus 15 minutes and counting. The planned hold in the countdown has concluded. Clocks will now tick down to T-minus 4 minutes where the final hold is scheduled. Launch is still set for 8:38 p.m.

0009 GMT (8:09 p.m. EDT Wed.)

Everyone has voiced readiness to proceed with the count.

0008 GMT (8:08 p.m. EDT Wed.)

The launch team is being polled for "ready" status to resume the countdown at the end of the hold as scheduled.

0005 GMT (8:05 p.m. EDT Wed.)

NASA launch manager Omar Baez performed a poll of the agency team for a "go" to continue with the count. No problems were reported.

0003 GMT (8:03 p.m. EDT Wed.)

Now half-way through this built-in hold.

0000 GMT (8:00 p.m. EDT Wed.)

Launch team and management polls will be coming up shortly. Once the countdown resumes, clocks will tick down to the T-minus 4 minute mark where a 10-minute hold is planned.

2353 GMT (7:53 p.m. EDT)

T-minus 15 minutes and holding. The countdown has entered the 20-minute built-in hold. The pause is designed to give the launch team a chance to catch up on activities that could be running behind schedule. Engineers will also have time to examine all the data from the just-completed steering tests.

2350 GMT (7:50 p.m. EDT)

Launch weather officer Joel Tumbiolo just gave another update to the management team. Everything continues to be excellent for launch tonight. The forecast calls for some thin high-level clouds, a light northeasterly wind less than 10 knots and a temperature between 62 and 64 degrees F.

2348 GMT (7:48 p.m. EDT)

The first stage steering checks are finished.

2344 GMT (7:44 p.m. EDT)

The second stage engine slews have been completed.

2343 GMT (7:43 p.m. EDT)

The launch team is beginning the "slew" or steering checks of the first and second stage engines. These are gimbal tests of the nozzles on the first stage main engine and twin vernier engines and second stage engine to ensure the rocket will be able to steer itself during launch.

2338 GMT (7:38 p.m. EDT)

Sixty minutes from launch. All systems are "go" for liftoff at 8:38 p.m. EDT. No problems have been reported with the Delta rocket, STEREO spacecraft or ground network. And the weather is perfect tonight.

2337 GMT (7:37 p.m. EDT)

The Range tests have been accomplished without an problems voiced. In about five minutes, engine steering tests will be conducted on the Delta 2 launch vehicle.

2332 GMT (7:32 p.m. EDT)

Inhibited checks are now beginning for the Range Safety command destruct receivers that would be used in destroying the Delta rocket should the vehicle veer off course and malfunction during the launch.

2329 GMT (7:29 p.m. EDT)

Checks of the rocket's safety system is coming up next.

2322 GMT (7:22 p.m. EDT)

Loading of the Delta 2 rocket's first stage liquid oxygen tank has finished. The operation took 27 minutes, 32 seconds and was completed at 7:22:09 p.m. The tank will be replenished through the countdown to replace the supercold liquid oxygen that naturally boils away.

The rocket now stands fully fueled for launch of the STEREO spacecraft. The vehicle's first stage was successfully loaded with RP-1 kerosene fuel along with the liquid oxygen this evening. The second stage was filled with its storable fuels -- 726 gallons of nitrogen tetroxide and 620 gallons of Aerozine 50 propellant -- on Monday. The nine strap-on booster rockets and third stage use solid propellants.

2314 GMT (7:14 p.m. EDT)

Now passing the 20-minute mark of this approximate 25-minute cryogenic tanking process for the Delta rocket's first stage. Bright white vapor is streaming from a vent port on the side of the vehicle.

Once the liquid oxygen tank reaches the 95 percent full level, the "rapid load" valve will be closed and the slower "fine load" phase will continue to fill the tank.

2309 GMT (7:09 p.m. EDT)

Now 15 minutes into liquid oxygen loading. The bottom of the Boeing Delta 2 rocket is icing over as the supercold liquid oxygen continues to flow into the first stage.

2308 GMT (7:08 p.m. EDT)

The countdown is entering the last 90 minutes to launch. Liftoff remains on schedule for 8:38 p.m. EDT.

2300 GMT (7:00 p.m. EDT)

As the sun sets on Cape Canaveral, fueling of the Delta rocket for tonight's launch of the STEREO solar observatories is progressing smoothly.

2254 GMT (6:54 p.m. EDT)

Cryogenic liquid oxygen, chilled to Minus-298 degrees F, has started flowing from the storage reservoir at Complex 17, through plumbing and into the bottom of the Boeing Delta 2 rocket. The LOX will be consumed by the first stage main engine during the first four-and-a-half minutes of flight along with the 10,000 gallons of RP-1 kerosene already loaded aboard the vehicle.

2248 GMT (6:48 p.m. EDT)

The launch team is beginning preps for loading the first stage with 14,700 gallons of liquid oxygen.

2246 GMT (6:46 p.m. EDT)

The launch team has completed work to turn on and configure the Delta's onboard guidance computer.

2242 GMT (6:42 p.m. EDT)

NASA launch manager Omar Baez reports "everything looks good for a launch tonight." He just completed a poll of the agency team for a "go" to begin liquid oxygen loading.

2238 GMT (6:38 p.m. EDT)

Two hours and counting to launch of the STEREO mission to capture the first 3-D views of the sun.

2235 GMT (6:35 p.m. EDT)

It is truly a beautiful night for a rocket launch from Cape Canaveral. Skies are clear, winds are light and temperatures are comfortable for spectators along the Space Coast beaches.

Launch weather officer Joel Tumbiolo just briefed mission managers ahead of liquid oxygen loading. There are no concerns and a 100 percent chance of acceptable conditions at liftoff time.

2220 GMT (6:20 p.m. EDT)

The first stage fuel tank of the Boeing Delta 2 rocket has been fully loaded for this evening's planned 8:38 p.m. launch. The tank was filled with a highly refined kerosene, called RP-1, during a 17-minute, 49-second process that concluded at 6:20:15 p.m. EDT.

The next major task in the count will be loading super-cold cryogenic liquid oxygen into the first stage starting in about 40 minutes.

The kerosene and liquid oxygen will be consumed by the stage's Pratt & Whitney Rocketdyne RS-27A main engine and twin vernier steering thrusters during the initial four-and-a-half minutes of flight.

2218 GMT (6:18 p.m. EDT)

Rapid-loading of the RP-1 tank has concluded as 9,800 gallons have been pumped into the rocket. Fine load is continuing.

2217 GMT (6:17 p.m. EDT)

Now 15 minutes through this 20-minute process to load the rocket's first stage with kerosene fuel. Some 8,000 gallons have been loaded to this point.

2212 GMT (6:12 p.m. EDT)

The launch team has computed that the full load for the first stage fuel tank is 9,982 gallons.

Once the tank is filled to 98 percent or 9,800 gallons, the "rapid load" valve will be closed and the slower "fine load" phase will continue to top off the tank.

2210 GMT (6:10 p.m. EDT)

First stage propellant loading has passed the 5,000-gallon mark.

2202 GMT (6:02 p.m. EDT)

Fueling of the Delta 2 rocket's first stage has begun. About 10,000 gallons of the kerosene propellant, called RP-1, are being pumped into the base of the rocket from storage tanks at pad 17B.

2158 GMT (5:58 p.m. EDT)

Preparations for loading the Delta 2 rocket's first stage RP-1 fuel tank are beginning. After verifying valves, sensors, flow meters and equipment are ready, the highly-refined kerosene fuel will start flowing into the vehicle a few minutes from now.

2155 GMT (5:55 p.m. EDT)

Pressurization of the first stage helium and nitrogen systems is complete. The next event in the countdown will be first stage fueling.

2141 GMT (5:41 p.m. EDT)

Activation of the rocket's Redundant Inertial Flight Control Assembly (RIFCA) guidance computer is beginning. Also, the launch team is starting pressurization steps for the first and second stage helium and nitrogen systems and second stage fuel tanks.

2139 GMT (5:39 p.m. EDT)

Some additional images from tower rollback have been posted here.

2138 GMT (5:38 p.m. EDT)

T-minus 150 minutes and counting. The Terminal Countdown is now underway for this evening's launch of the Delta 2 rocket and NASA's Solar Terrestrial Relations Observatory (STEREO) mission. The next three hours will be spent fueling the rocket, activating systems and performing final testing before liftoff at 8:38 p.m. EDT (0338 GMT) from pad 17B at Cape Canaveral Air Force Station in Florida.

The Complex 17 area is verified cleared of workers. A warning horn will be sounded three times at the seaside complex as a precaution to alert any remaining personnel in the vicinity that they should leave immediately.

The pad clear status will allow the start of hazardous operations such as the pressurization of helium and nitrogen storage tanks inside the rocket's first and second stages, along with the second stage fuel and oxidizer tanks.

The countdown currently stands at T-minus 150 minutes. However, two holds -- totaling 30 minutes in duration -- are planned at T-minus 15 minutes and T-minus 4 minutes.

2129 GMT (5:29 p.m. EDT)

The launch team members have been polled for a "ready" status to resume the countdown as planned at the end of this hold. No constraints were voiced. Clocks will start ticking again at 5:38 p.m. EDT as the Terminal Count begins.

2112 GMT (5:12 p.m. EDT)

A collection of photos taken earlier this afternoon during rollback of the mobile service tower is posted here.

Read our earlier status center coverage.