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The Mission




Rocket: Atlas 5 (AV-005)
Payload: AMC 16
Date: December 17, 2004
Window: 4:41-7:21 a.m. EST (0941-1221 GMT)
Site: Complex 41, Cape Canaveral, Florida
Satellite feed: AMC 9, Transponder 4, C-band, 85° West

Mission preview story

Launch events timeline

Ground track map

Orbit insertion graphic

Launch hazard area

Cape's Complex 41

Atlas 5 info

AMC 16 facts



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Launch of Atlas 5
The Lockheed Martin Atlas 5 rocket launches at 7:07 a.m. EST from Cape Canaveral carrying the AMERICOM 16 communications spacecraft. (6min 22sec file)
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Press site view
The sunrise launch of Atlas 5 is shown in this view from the Kennedy Space Center press site at Complex 39. (QuickTime file)
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Rocket rollout
Riding on its mobile launching platform, the Atlas 5 rocket is rolled from its assembly building to the launch pad at Complex 41 just hours before the scheduled liftoff time carrying AMC 16. (4min 41sec file)
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Atlas 5 news briefing
Mission officials hold the pre-launch news conference in Cape Canaveral on Thursday, Dec. 16 to preview the flight of Atlas 5 with AMC 16. (40min 41sec file)
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AMC 16 launch preview
Preview the launch of Lockheed Martin's Atlas 5 rocket carrying the AMERICOM 16 communications spacecraft with this narrated animation package. (2min 52sec file)
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The AMC 16 spacecraft
This narrated movie provides an overview of the Lockheed Martin-built AMC 16 spacecraft for operator SES AMERICOM. (3min 30sec file)
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Last Atlas 2AS rocket
Lockheed Martin's last Atlas 2AS rocket blasts off from Cape Canaveral carrying a classified National Reconnaissance Office spacecraft on August 31. (3min 59sec file)
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Salute to pad 36A
The Atlas launch team in the Complex 36 Blockhouse celebrate the history of pad 36A in a post-launch toast. The Atlas 2AS rocket flight was the last to launch from the pad, which entered service in 1962. (2min 09sec file)
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Mission success
The classified NRO payload is deployed from the Centaur upper stage to successfully complete the launch. (1min 56sec file)
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BY JUSTIN RAY

Follow the countdown and launch of the Lockheed Martin Atlas 5 rocket with the AMC 16 commercial communications satellite. Reload this page for the very latest on the mission.

Spaceflight Now Plus
Additional coverage for subscribers:
VIDEO: 6-MINUTE CLIP OF THE ATLAS 5 LAUNCH WITH AMC 16 QT
VIDEO: LAUNCH AS SEEN FROM THE COMPLEX 39 PRESS SITE QT
VIDEO: AMC 16 SUCCESSFULLY DEPLOYED FROM THE ROCKET QT
VIDEO: ATLAS 5 ROCKET IS ROLLED TO THE LAUNCH PAD QT
VIDEO: THURSDAY'S PRE-LAUNCH NEWS CONFERENCE QT
VIDEO: NARRATED ANIMATION PREVIEW OF THIS LAUNCH QT
VIDEO: OVERVIEW OF THE AMERICOM 16 SPACECRAFT QT
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FRIDAY, DECEMBER 17, 2004

Call it the ultimate whirlwind experience in the rocket business. In the span of 12 hours, Lockheed Martin's Atlas 5 rocket went to the launch pad, took on its fuel, persevered through a couple of technical bugs, roared off the planet on 31 million horsepower and was rewarded with another success as it deployed a commercial satellite cargo into orbit. Read our full story.

1410 GMT (9:10 a.m. EST)

To recap, this morning's launch began at 7:07 a.m. EST (1207 GMT) from Cape Canaveral Air Force Station, Florida. The 196-foot tall, 959,000-pound rocket thundered away from Complex 41 on the thrust of its powerful RD-180 main engine and twin solid rocket boosters.

Liftoff was delayed from the original target of 4:41 a.m. EST (0941 GMT) due to extra time needed overnight to complete launch pad preps, a troublesome position indicator on the first stage liquid oxygen fill and drain valve halted the countdown inside T-minus 3 minutes and a few additional minutes required to update the flight profile in the rocket's guidance computer based on the latest upper level wind conditions.

With 14 minutes to spare in the day's launch window, Lockheed Martin's fourth Atlas 5 departed the launch pad carrying the 9,000-pound AMERICOM 16 spacecraft. The satellite was successfully carried into geosynchronous transfer orbit and deployed an hour and 49 minutes after liftoff.

The next launch for Lockheed Martin will be the sixth and final flight for the Atlas 3 rocket fleet when a classified National Reconnaissance Office payload is hauled to space on January 27 from the Cape. The next Atlas 5 is targeted for March 10 carrying the commercial INMARSAT mobile communications satellite.

This will complete our live play-by-play coverage. We will post a wrap-up story and pictures later today.

1404 GMT (9:04 a.m. EST)

Controllers received a bit of data from the AMC 16 spacecraft prior to separation via a ground tracking station. Key systems were working normally, Lockheed Martin says. Full contact will be upcoming shortly.

1356 GMT (8:56 a.m. EST)

This completes the fourth flight of Lockheed Martin's next-generation Atlas 5 rocket, all of which have been successful. It also extends the string of successful missions by the Atlas family to 74 dating back to 1993.

1355 GMT (8:55 a.m. EST)

T+plus 1 hour, 48 minutes, 43 seconds. SPACECRAFT SEPARATION! The AMERICOM 16 communications broadcasting satellite has been released into Earth orbit from the Centaur!

The AMC 16 spacecraft will be operated by Princeton, New Jersey-based SES AMERICOM. Direct-to-home television service provider EchoStar has a deal with SES AMERICOM to use the satellite to beam its programming to DISH Network subscribers across the United States.

Built by Lockheed Martin using the A2100AX model design, AMC 16 features 12 Ka-band spot beams and 24 Ku-band transponders for broadband communications and television relay services to small roof-top satellite dishes.

1355 GMT (8:55 a.m. EST)

T+plus 1 hour, 48 minutes. Centaur is in the spacecraft deploy position.

1354 GMT (8:54 a.m. EST)

T+plus 1 hour, 47 minutes, 40 seconds. The orbit achieved is on target, Lockheed Martin reports.

1353 GMT (8:53 a.m. EST)

T+plus 1 hour, 46 minutes, 30 seconds. The Centaur is in its reorientation maneuver to prepare for releasing the payload.

1353 GMT (8:53 a.m. EST)

T+plus 1 hour, 46 minutes. Normal engine shutdown signatures reported.

1352 GMT (8:52 a.m. EST)

T+plus 1 hour, 45 minutes, 52 seconds. MECO! The Centaur's Pratt & Whitney RL10 engine has shut down to complete its second of two firings this morning to launch AMC 16.

1352 GMT (8:52 a.m. EST)

T+plus 1 hour, 45 minutes. The engine is still performing well.

1351 GMT (8:51 a.m. EST)

T+plus 1 hour, 44 minutes. Less than two minutes remain in this engine firing.

1350 GMT (8:50 a.m. EST)

T+plus 1 hour, 43 minutes. Engine operating parameters are normal.

1349 GMT (8:49 a.m. EST)

T+plus 1 hour, 42 minutes, 30 seconds. Constant 0.8 g's acceleration as the Centaur performs this 4-minute firing.

1348 GMT (8:48 a.m. EST)

T+plus 1 hour, 41 minutes, 57 seconds. Engine ignition! Centaur is firing again to ferry AMC 16 from its initial parking orbit around Earth into geosynchronous transfer orbit.

1347 GMT (8:47 a.m. EST)

T+plus 1 hour, 40 minutes, 50 seconds. Propellant tank pressurization has begun.

1346 GMT (8:46 a.m. EST)

T+plus 1 hour, 39 minutes. About three minutes remain to the second burn by Centaur this morning.

1343 GMT (8:43 a.m. EST)

T+plus 1 hour, 35 minutes. Centaur has begun turning itself to the proper orientation for engine start.

1339 GMT (8:39 a.m. EST)

T+plus 1 hour, 32 minutes. Re-ignition of the RL10 engine is about 10 minutes away.

1317 GMT (8:17 a.m. EST)

T+plus 1 hour, 10 minutes. Centaur systems remain in good shape. The stage is in a gentle roll for thermal conditioning during the coast.

1303 GMT (8:03 a.m. EST)

T+plus 56 minutes. The next firing by Centaur is about 45 minutes away. Data from the rocket continues to indicate a normal coast through space as the vehicle heads to the desired altitude and position to re-ignite its main engine. The performance of the Atlas 5 will send AMC 16 into a higher than normal geosynchronous transfer orbit, thereby helping the satellite save its fuel supply during maneuvers to reach geostationary orbit. The fuel economy should allow added service life by the satellite, perhaps upwards of two decades in all.

1247 GMT (7:47 a.m. EST)

T+plus 40 minutes. The rocket's flight path from liftoff through deployment of AMC 16 in geosynchronous transfer orbit can be seen in this map. The spot labeled MECO 1 was the point in which the Centaur completed its first firing about 25 minutes ago.

1235 GMT (7:35 a.m. EST)

T+plus 28 minutes. Centaur is stable and operating correctly in the coast mode. Battery voltages and tank pressures are normal.

1224 GMT (7:24 a.m. EST)

T+plus 17 minutes. The rocket will coast in this parking orbit for nearly 90 minutes. The Centaur re-ignites at T+plus 1 hour, 42 minutes. Deployment of AMC 16 to complete today's launch is expected at T+plus 1 hour, 49 minutes.

1222 GMT (7:22 a.m. EST)

T+plus 15 minutes, 41 seconds. MECO 1. The Centaur main engine has cut off following the first of two planned firings to propel the AMC 16 TV satellite into the targeted geosynchronous transfer orbit today.

1222 GMT (7:22 a.m. EST)

T+plus 15 minutes. Data shows good performance from the Atlas first stage.

1221 GMT (7:21 a.m. EST)

T+plus 14 minutes, 45 seconds. About one minute remaining in this first firing by the Centaur upper stage this morning.

1220 GMT (7:20 a.m. EST)

T+plus 13 minutes, 45 seconds. The vehicle has gone orbital, and continues to burn the RL10 to reach the desired altitude.

1219 GMT (7:19 a.m. EST)

T+plus 12 minutes. Centaur continues to fire its engine to propel the rocket and AMC 16 payload into an initial parking orbit around Earth.

1218 GMT (7:18 a.m. EST)

T+plus 11 minutes. This first burn of the Centaur upper stage will continue until approximately T+plus 15 minutes, 47 seconds.

1217 GMT (7:17 a.m. EST)

T+plus 10 minutes, 20 seconds. Engine chamber pressures reported normal.

1216 GMT (7:16 a.m. EST)

T+plus 9 minutes. The Pratt & Whitney RL10 engine is burning a mixture of liquid oxygen and liquid hydrogen fuel.

1215 GMT (7:15 a.m. EST)

T+plus 8 minutes, 30 seconds. The rocket remains right on course with no problems reported.

1214 GMT (7:14 a.m. EST)

T+plus 7 minutes, 30 seconds. Centaur has performed a planned roll maneuver to align with NASA's Tracking and Data Relay Satellite System for communications.

1213 GMT (7:13 a.m. EST)

T+plus 6 minutes, 20 seconds. The upper stage continues to fire normally.

1212 GMT (7:12 a.m. EST)

T+plus 5 minutes, 10 seconds. The rocket is 300 miles east of the launch pad as Centaur begins its 11-minute firing to reach Earth orbit.

1211 GMT (7:11 a.m. EST)

T+plus 4 minutes, 55 seconds. Centaur's RL10 main engine has ignited!

1211 GMT (7:11 a.m. EST)

T+plus 4 minutes, 41 seconds. Main engine cutoff confirmed. And the spent first stage has separated!

1210 GMT (7:10 a.m. EST)

T+plus 3 minutes, 55 seconds. The new five-meter Atlas 5 payload fairing has been jettisoned! Also, the load-support ring on the Centaur has separated, too. Both the fairing and ring are built by Contraves Space.

1210 GMT (7:10 a.m. EST)

T+plus 3 minutes. The vehicle is 60 miles downrange as it soars into the sunrise.

1209 GMT (7:09 a.m. EST)

T+plus 2 minutes. 45 seconds. The Atlas 5 continues powering to space on the Russian-designed RD-180 first stage main engine.

1209 GMT (7:09 a.m. EST)

T+plus 2 minutes, 15 seconds. Both solid rocket boosters have been jettisoned from the Atlas 5. The Aerojet-made boosters, the world's longest single-segment solids, have completed their second launch.

1208 GMT (7:08 a.m. EST)

T+plus 95 seconds. Loss of data in the telemetry room at the launch control center, but rocket remains on the proper trajectory based on Range tracking.

1207 GMT (7:07 a.m. EST)

T+plus 45 seconds. The vehicle remains on course and performing normally.

1207 GMT (7:07 a.m. EST)

T+plus 25 seconds. Atlas 5 is performing its roll and pitch maneuvers to achieve the proper profile for minimuzing aerogynamic loads during the climb through Earth's atmosphere.

1207 GMT (7:07 a.m. EST)

T+plus 10 seconds. The rocket has ascended from the tower at Cape Canaveral's Complex 41 on the power of its RD-180 main engine and twin strap-on solid rocket boosters.

1207 GMT (7:07 a.m. EST)

LIFTOFF! Liftoff of Atlas 5 with AMERICOM 16 -- delivering a new communications satellite into space to relay television and broadband services across America.

1206 GMT (7:06 a.m. EST)

T-minus 20 seconds. "Go Atlas" "Go Centaur" called by launch team, verifying all systems are ready.

1205 GMT (7:05 a.m. EST)

T-minus 90 seconds. Launch control system is enabled. The Flight Termination System has been armed.

1205 GMT (7:05 a.m. EST)

T-minus 2 minutes. The Atlas first stage and Centaur upper stage are now switching to internal power. Liquid oxygen and liquid hydrogen topping for Centaur will be stopped in 10 seconds.

1204 GMT (7:04 a.m. EST)

T-minus 2 minutes, 40 seconds. The Flight Termination System has switched to internal power.

1204 GMT (7:04 a.m. EST)

T-minus 3 minutes. The Atlas first stage liquid oxygen replenishment is being secured so the tank can be pressurized for flight. Also, the RP-1 tank is being pressurized to flight level.

1203 GMT (7:03 a.m. EST)

T-minus 4 minutes and counting. Clocks are ticking again for liftoff of the Lockheed Martin Atlas 5 and the AMC 16 communications satellite at 7:07 a.m. EST (1207 GMT) from Cape Canaveral, Florida. The automatic computer sequencer is in control of all the critical events through liftoff.

1201 GMT (7:01 a.m. EST)

The final approval has been given to resume the clock at 7:03 a.m. for liftoff four minutes later.

1200 GMT (7:00 a.m. EST)

Launch team members have been polled for a "go" to continue the countdown.

1159 GMT (6:59 a.m. EST)

The rocket's guidance computer has received the profile with no problem.

1158 GMT (6:58 a.m. EST)

The loading of the flight profile into the rocket based on the latest weather balloon is occurring. This will allow liftoff 9 minutes from now.

1155 GMT (6:55 a.m. EST)

Dawn is breaking along Florida's east coast. This morning's launch could be spectacular, occurring a minute before official sunrise.

1153 GMT (6:53 a.m. EST)

The readiness polls of the launch team are now reset for 7:00 a.m. The countdown would resume at 7:03 a.m. from the T-minus 4 minute mark.

1151 GMT (6:51 a.m. EST)

NEW LAUNCH TIME! Liftoff has been scheduled for 7:07 a.m. EST.

1148 GMT (6:48 a.m. EST)

The upper level winds are monitored by a series of weather balloons dispatched throughout the countdown. That data is used to generate ascent profiles for the rocket to safely fly through the atmosphere.

1143 GMT (6:43 a.m. EST)

A flight profile based on the upper level wind conditions should be available around 6:50 a.m. EST. Once that is loaded into the rocket and verified, a new liftoff time can be established. Liftoff must occur by 7:21 a.m. EST this morning or else the mission will be scrubbed for the day.

1141 GMT (6:41 a.m. EST)

NO GO! High-altitude winds are presently no go for liftoff.

1141 GMT (6:41 a.m. EST)

The launch team will be polled for a final readiness check in two minutes. The countdown is expected to resume at 6:46 a.m.

1139 GMT (6:39 a.m. EST)

The problem with a valve position indicator glitch. The launch team has developed a workaround procedure to confirm the valve is closed as designed without the faulty indicator tripping up the countdown sequencer.

1138 GMT (6:38 a.m. EST)

NEW LAUNCH TIME! Liftoff is being targeted for 6:50 a.m. EST (1150 GMT).

1129 GMT (6:29 a.m. EST)

A cycle test of the fill and drain valve has been completed. Analysis and discussion continues.

1127 GMT (6:27 a.m. EST)

There is no estimate on when the problem will be resolved or when liftoff could occur. Troubleshooting is underway. The countdown is holding at T-minus 4 minutes.

1125 GMT (6:25 a.m. EST)

The problem involves the first stage liquid oxygen fill and drain valve. The launch team is planning to run some tests to determine the nature of the problem -- whether it is the valve itself or just an indicator problem.

1121 GMT (6:21 a.m. EST)

One hour remains in today's launch window.

1118 GMT (6:18 a.m. EST)

To recap, the countdown was stopped with less than three minutes until liftoff time when a fault was detected. The vehicle has been safed and the launch team is awaiting resolution of the problem in hopes of trying another countdown before the end of this morning's launch opportunity, which closes at 7:21 a.m. EST.

1115 GMT (6:15 a.m. EST)

The AMC 16 spacecraft remains on internal power in the countdown hold.

1114 GMT (6:14 a.m. EST)

A Lockheed Martin spokesman says a valve problem prompted the countdown sequencer to halt the clock.

1112 GMT (6:12 a.m. EST)

Launch team members are recycling their various systems to the T-minus 4 minute mark configuration.

1111 GMT (6:11 a.m. EST)

Today's launch window extends to 7:21 a.m. EST (1221 GMT).

1111 GMT (6:11 a.m. EST)

Engineers are troubleshooting the problem that stopped this morning's countdown. There's been no word yet on the exact nature of the glitch.

1110 GMT (6:10 a.m. EST)

Vehicle safing is underway as part of normal countdown hold procedures.

1109 GMT (6:09 a.m. EST)

Countdown is being recycled to T- minus 4 minutes.

1109 GMT (6:09 a.m. EST)

A problem was detected at T-minus 2 minutes, 38 seconds, stopping the countdown.

1108 GMT (6:08 a.m. EST)

HOLD!

1108 GMT (6:08 a.m. EST)

T-minus 2 minutes, 40 seconds. The Flight Termination System has switched to internal power.

1108 GMT (6:08 a.m. EST)

T-minus 3 minutes. The Atlas first stage liquid oxygen replenishment is being secured so the tank can be pressurized for flight. Also, the RP-1 tank is being pressurized to flight level.

1107 GMT (6:07 a.m. EST)

T-minus 4 minutes and counting. The final countdown is now underway for the launch of Lockheed Martin Atlas 5 and the AMC 16 communications satellite! The automatic computer sequencer is in control of all the critical events through liftoff.

1106 GMT (6:06 a.m. EST)

Standing by to resume the countdown.

1105 GMT (6:05 a.m. EST)

Launch Director Adrian Laffitte has also given his "go" to continue the countdown in about 2 minutes. Liftoff is set for 6:11 a.m. EST.

1104 GMT (6:04 a.m. EST)

The launch team has been polled by the launch conductor from the Atlas 5 Spaceflight Operations Center. Everyone has now reported a "go" status for flight.

1102 GMT (6:02 a.m. EST)

Weather conditions remain "go" for launch.

1100 GMT (6:00 a.m. EST)

The entire launch team will be polled in four minutes to verify readiness to resume the countdown for liftoff at 6:11 a.m. EST.

1059 GMT (5:59 a.m. EST)

AMC 16 is running on internal power.

1058 GMT (5:58 a.m. EST)

The solid rocket booster ignition safe and arm switch is being put in the "enable" position.

1057 GMT (5:57 a.m. EST)

T-minus 4 minutes and holding. The countdown has entered this final planned hold. The pause is scheduled to last 10 minutes. Launch remains slated for 6:11 a.m. EST, pending no technical issues and acceptable weather.

1056 GMT (5:56 a.m. EST)

All three cryogenic liquid hydrogen and liquid oxygen tanks aboard the rocket have reached flight level.

1056 GMT (5:56 a.m. EST)

The AMC 16 spacecraft payload sitting atop the Atlas 5 rocket is now switching from ground-fed power to internal batteries for flight.

1051 GMT (5:51 a.m. EST)

T-minus 10 minutes and counting. Coming up on the built-in hold at T-minus 4 minutes.

1045 GMT (5:45 a.m. EST)

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

1041 GMT (5:41 a.m. EST)

T-minus 20 minutes and counting. The countdown clocks are heading to the T-minus 4 minute mark where a planned 10-minute hold will begin at 5:57 a.m. EST. Liftoff is still set for 6:11 a.m. EST (1111 GMT).

1037 GMT (5:37 a.m. EST)

The Centaur liquid hydrogen tank has achieved flight level.

1031 GMT (5:31 a.m. EST)

Launch is 40 minutes away.

1027 GMT (5:27 a.m. EST)

The fast-fill loading of the first stage liquid oxygen tank has been completed to 97 percent. Topping off of the tank is now starting.

The rocket is nearly fully fueled for launch. However, the liquid oxygen and liquid hydrogen cryogenics being pumped into the rocket this morning are chilled to several hundred degrees below zero and naturally boil away. So the supplies must be replenished through the countdown.

1023 GMT (5:23 a.m. EST)

First stage liquid oxygen has reached 90 percent.

1021 GMT (5:21 a.m. EST)

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

1018 GMT (5:18 a.m. EST)

Centaur liquid hydrogen tank is now at 80 percent and still filling.

1012 GMT (5:12 a.m. EST)

Atlas first stage liquid oxygen has hit the 70 percent mark. The Centaur hydrogen tank is 40 percent full.

1009 GMT (5:09 a.m. EST)

The Centaur liquid hydrogen tank has reached 20 percent.

1006 GMT (5:06 a.m. EST)

The flight control final preparations are starting.

Meanwhile, all weather rules are now "go" for launch again.

1004 GMT (5:04 a.m. EST)

The liquid hydrogen chilldown is now complete and the super-cold fuel is flowing to fill the Centaur upper stage. The cryogenic propellant will be consumed with liquid oxygen by the stage's Pratt & Whitney-made RL10 engine to propel the AMC 16 spacecraft into the targeted geosynchronous transfer orbit this morning.

1003 GMT (5:03 a.m. EST)

First stage liquid oxygen tank is now half full.

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-and-a-half minutes of flight today.

1003 GMT (5:03 a.m. EST)

The Centaur engine chilldown has been initiated.

0954 GMT (4:54 a.m. EST)

A layer of ice is slowly beginning to form on the liquid oxygen section of the Atlas 5 first stage as the cryogenic oxidizer continues to flow into the stage.

0950 GMT (4:50 a.m. EST)

The Centaur liquid oyxgen tank has reached flight level.

0948 GMT (4:48 a.m. EST)

The first stage liquid oxygen tank is now 10 percent full.

0944 GMT (4:44 a.m. EST)

The Centaur liquid oxygen tank has now reached the 95 percent level. Topping is starting.

0941 GMT (4:41 a.m. EST)

Time to launch is 90 minutes. Today's launch window is now open. But liftoff has been pushed back to 6:11 a.m. EST after pre-flight work at the pad took longer than expected overnight. Weather conditions remain "no go" at this time due to clouds and showers in the area. However, there is plenty of time for the weather to improve. Fueling of the rocket is underway at Complex 41.

0939 GMT (4:39 a.m. EST)

The chilldown conditioning of liquid hydrogen propellant lines at Complex 41 is now starting to prepare the plumbing for transferring the Minus-423 degree F fuel into the rocket.

0937 GMT (4:37 a.m. EST)

The 70 percent point has been reach on the Centaur liquid oxygen tank.

0935 GMT (4:35 a.m. EST)

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 super-cold liquid oxygen into the Atlas 5's first stage.

The Atlas liquid oxygen tank is the largest tank to be filled today.

The propellant for the first stage -- the RP-1 kerosene -- was loaded aboard the rocket a couple of hours ago.

0932 GMT (4:32 a.m. EST)

The Centaur liquid oxygen tank is now half full.

0929 GMT (4:29 a.m. EST)

The disturbed weather rule is showing "no go" status at this time. There are showers drifting ashore this morning from the Atlantic.

0926 GMT (4:26 a.m. EST)

The upper stage liquid oxygen tank is 20 percent full as cryogenic fueling of the Atlas 5 rocket continues in its early phases for this morning's 6:11 a.m. EST launch.

0922 GMT (4:22 a.m. EST)

A check of current weather conditions shows the thick cloud rule is being violated. This rule says the rocket cannot launch through cloud cover greater than 4,500 feet thick because of concerns for triggered lightning that would destroy the vehicle.

0919 GMT (4:19 a.m. EST)

Following the thermal conditioning of the transfer pipes, Centaur liquid oxygen tanking operations have begun.

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.

0912 GMT (4:12 a.m. EST)

The Centaur liquid oxygen transfer line chilldown is starting in advance of loading the upper stage. This thermal conditioning prepares the plumbing for flowing the cryogenic oxidizer.

0911 GMT (4:11 a.m. EST)

Now two hours remain until the targeted liftoff time.

0901 GMT (4:01 a.m. EST)

T-minus 120 minutes and counting! The countdown has resumed following a two-hour hold, which was 90 minutes longer than planned so the pad crew could finish its work configuring Complex 41 for today's liftoff. Launch is scheduled to occur at 6:11 a.m. EST today. One more planned hold is slated for T-minus 4 minutes and will last 10 minutes in duration.

Activities upcoming include pressurizing the RP-1 first stage fuel tank and liquid oxygen chilldown procedures.

0857 GMT (3:57 a.m. EST)

The launch team has been polled for a readiness to press ahead with cryogenic fueling operations this morning. No problems were reported.

0856 GMT (3:56 a.m. EST)

The blast danger area around the launch pad has been confirmed clear of all personnel. Safety officials make this confirmation before the hazardous operations of fueling the rocket starts.

0855 GMT (3:55 a.m. EST)

The launch team is receiving a procedures briefing from the launch conductor in preparation for picking up the countdown.

0850 GMT (3:50 a.m. EST)

The countdown is scheduled to resume ticking at 4:01 a.m. EST, leading to liftoff at 6:11 a.m. EST this morning. A poll of the launch team to verify readiness for fueling is coming up shortly.

0823 GMT (3:23 a.m. EST)

NEW LAUNCH TIME! Another half-hour is being added to the countdown to complete some steps before fueling can start. Liftoff has been slipped to 6:11 a.m. EST (1111 GMT). Today's available launch window extends to 7:21 a.m. EST (1221 GMT).

0822 GMT (3:22 a.m. EST)

The pad workers have finished their pre-launch chores and are leaving the complex.

0752 GMT (2:52 a.m. EST)

NEW LAUNCH TIME! An additional 30 minutes are being added to this ongoing hold in the countdown. Liftoff will be rescheduled to 5:41 a.m. EST (1041 GMT), giving more time to complete launch pad configuring.

0739 GMT (2:39 a.m. EST)

Technicians at the pad say they have about 15-20 minutes of work to go as they finish prepping the flame bucket. Once they are clear of the mobile launcher platform, precursors to fueling operations can begin.

Read our earlier status center coverage.

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