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Atlas blasts off
Lockheed Martin's last Atlas 2AS rocket blasts off from Cape Canaveral carrying a classified National Reconnaissance Office spacecraft. (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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Hurricane Frances
An external camera aboard the International Space Station captured this dramatic view of Hurricane Frances churning in the Atlantic Ocean. (4min 46sec file)
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Monday's Atlas scrub
Stormy weather over Cape Canaveral caused the launch of the Atlas 2AS rocket to be scrubbed on August 30. (44sec file)
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Atlas launch preview
Preview the launch of Lockheed Martin's Atlas 2AS rocket carrying a classified National Reconnaissance Office spacecraft with this narrated animation package. (2min 22sec file)
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Sunday's Atlas scrub
Unacceptable weather conditions force the Atlas rocket's countdown to be stopped at T-minus 90 seconds on August 29. (1min 36sec file)
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Saturday's Atlas scrub
A shortage of liquid oxygen caused by a mis-configured valve prompts Lockheed Martin to scrub the August 28 attempt to launch the final Atlas 2AS rocket from Cape Canaveral. (1min 26sec file)
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The Mission




Rocket: Atlas 2AS (Atlas/Centaur-167)
Payload: NRO
Date: August 31, 2004
Time: 6:49 p.m. EDT (2249 GMT)
Site: Complex 36A, Cape Canaveral, Florida
Satellite feed: Intelsat Americas 5, Transponder 16, C-band, 97° West

Launch events timeline

Ground track map

Launch hazard area




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The Launcher




Lockheed Martin's Atlas 2AS rocket, equipped with four strap-on solid boosters, makes its 30th and final flight during this NRO launch.

Atlas 2AS fact sheet

Rocket's launch record

Archived Atlas coverage





BY JUSTIN RAY

Follow the countdown and launch of the Lockheed Martin Atlas 2AS rocket with a classified National Reconnaissance Office payload. Reload this page for the very latest on the mission.

Spaceflight Now Plus
Additional coverage for subscribers:
VIDEO: FINAL ATLAS 2AS ROCKET BLASTS OFF QT
VIDEO: LAUNCH TEAM SALUTES PAD 36A AFTER ITS LAST LAUNCH QT
VIDEO: NRO PAYLOAD IS DEPLOYED FROM CENTAUR UPPER STAGE QT

VIDEO: WEATHER SCRUBS MONDAY'S COUNTDOWN QT
VIDEO: PREVIEW THIS ATLAS LAUNCH WITH NARRATED ANIMATION QT
VIDEO: SUNDAY'S COUNTDOWN IS HALTED AT T-90 SECONDS QT
VIDEO: SATURDAY'S COUNTDOWN IS SCRUBBED QT
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TUESDAY, AUGUST 31, 2004

Lockheed Martin's Atlas 2 family of boosters rocketed into retirement Tuesday, placing a classified U.S. national security satellite into space following a sunset sendoff from Cape Canaveral. Read our full launch story.

It was the starting point for dozens of commercial communications satellites, military spacecraft and pioneering space probes, including the first man-made object to journey outside our solar system. But after 42 years of Atlas rocket launches, pad 36A saw its final blastoff Tuesday night. Read our full story.

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

The Atlas 2 family of rockets has completed its 63rd and final flight with good flight tonight, lofting the NRO payload into orbit. The vehicle fleet (2, 2A and 2AS models) retires with 100 percent mission success dating to 1991.

For the overall Atlas program, this is the 73rd consecutive successful launch since 1993.

The next mission is scheduled for early December when the next-generation Atlas 5 will carry a commercial communications satellite into space from the Cape.

0030 GMT (8:30 p.m. EDT Tues.)

T+plus 73 minutes, 58 seconds. SPACECRAFT SEPARATION! A classified spacecraft for the U.S. National Reconnaissance Office has been delivered into space by the Lockheed Martin Atlas 2AS rocket!

0030 GMT (8:30 p.m. EDT Tues.)

T+plus 73 minutes. Less than a minute to payload deploy. Spin-up is progressing normally.

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

T+plus 72 minutes. The upper stage has started spinning up to 5 rpm in advance of spacecraft release.

0027 GMT (8:27 p.m. EDT Tues.)

T+plus 70 minutes, 45 seconds. Centaur has begun a maneuver to the proper position for satellite deployment.

0026 GMT (8:26 p.m. EDT Tues.)

T+plus 69 minutes, 57 seconds. MECO 2. The Centaur engines have shut down to complete the powered phase of today's launch. Deployment of the satellite is four minutes away.

0026 GMT (8:26 p.m. EDT Tues.)

T+plus 69 minutes, 30 seconds. The burn continues normally.

0026 GMT (8:26 p.m. EDT Tues.)

T+plus 69 minutes. Both engines are up and firing. Proper ignition start-up signatures reported in the telemetry.

0025 GMT (8:25 p.m. EDT Tues.)

T+plus 68 minutes, 46 seconds. Ignition and full thrust! The Pratt & Whitney RL10 engines of the Centaur upper stage are firing for the burn to boost the NRO spacecraft cargo from the current parking orbit to the desired orbit for deployment from the launch vehicle.

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

T+plus 67 minutes, 40 seconds. The Centaur pre-ignition sequence is started, positioning valves, pressurizing the tanks and readying the engines for start.

0023 GMT (8:23 p.m. EDT Tues.)

T+plus 66 minutes. Centaur systems are still looking good as the ignition time nears.

0021 GMT (8:21 p.m. EDT Tues.)

T+plus 64 minutes. Less than five minutes until the Centaur ignites again.

0020 GMT (8:20 p.m. EDT Tues.)

T+plus 63 minutes. Centaur is beginning a maneuver to the engine restart orientation.

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

T+plus 61 minutes. Pitch, yaw and roll rates remain normal, pressures and voltages also as expected.

0017 GMT (8:17 p.m. EDT Tues.)

T+plus 60 minutes. Now one hour into this finale flight of Lockheed Martin's Atlas 2AS rocket.

0012 GMT (8:12 p.m. EDT Tues.)

T+plus 55 minutes. Latest Centaur health check still showing systems are operating well.

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

T+plus 51 minutes. Centaur continues to fly in its normal sequence with no problems reported during tonight's launch.

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

T+plus 48 minutes. Now 20 minutes away from restart of the Centaur engines.

2358 GMT (7:58 p.m. EDT)

T+plus 41 minutes. A status check of Centaur systems shows the rate of motion, tank and bottle pressures and power voltage all still normal.

2352 GMT (7:52 p.m. EDT)

T+plus 35 minutes. NASA's Tracking and Data Relay Satellite System continues to follow the rocket as it orbits Earth, receiving live telemetry from the vehicle for transmission back to engineers at Cape Canaveral.

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

T+plus 33 minutes. The second of two planned firings by the Centaur to deliver the NRO spacecraft into the right orbit for release begins at about T+plus 68 minutes. That firing will last about 75 seconds. Deployment of the satellite to complete this launch occurs at about T+plus 74 minutes.

2346 GMT (7:46 p.m. EDT)

T+plus 29 minutes. Live telemetry during this coast shows that the 33-foot long Centaur remains in a good state with normal rates of motion. Tank and bottle pressures are acceptable and the batteries are healthy.

2340 GMT (7:40 p.m. EDT)

T+plus 23 minutes. Lockheed Martin confirms that this parking orbit achieved is right on target, indicating good performance by the rocket so far.

2339 GMT (7:39 p.m. EDT)

T+plus 22 minutes. The Atlas will deliver its classified National Reconnaissance Office payload into a highly inclined orbit. For a track of today's launch, see a map here.

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

T+plus 15 minutes. The launch team has just toasted pad 36A, which retires tonight after 42 years of supporting Atlas-Centaur rocket flights.

2328 GMT (7:28 p.m. EDT)

T+plus 11 minutes. The vehicle is in good shape as it enters an hour-long coast period before engines are restarted over the South Pacific to accelerate the classified payload into its intended orbit tonight.

2327 GMT (7:27 p.m. EDT)

T+plus 10 minutes, 8 seconds. MECO 1. The Centaur main engines have shut down as planned following the first of two planned firings to propel the NRO spacecraft into the proper orbit.

2326 GMT (7:26 p.m. EDT)

T+plus 9 minutes, 40 seconds. The rocket is now 110 miles in altitude, 1,040 miles downrange, traveling at 14,000 mph.

2326 GMT (7:26 p.m. EDT)

T+plus 9 minutes. Engine parameters reported normal.

2325 GMT (7:25 p.m. EDT)

T+plus 8 minutes. The Centaur stage remains stable with a good engine burn in progress. About two minutes remain in this firing.

2324 GMT (7:24 p.m. EDT)

T+plus 7 minutes. The vehicle has rolled to an orientation for communications with NASA's Tracking and Data Relay Satellite System.

2323 GMT (7:23 p.m. EDT)

T+plus 6 minutes. Vehicle continues right down the predicted Range track at an altitude of 102 miles, 429 miles downrange and traveling at 8,800 mph.

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

T+plus 5 minutes, 45 seconds. Centaur continues to fire its cryogenic engines normally.

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

T+plus 5 minutes, 26 seconds. The Centaur's twin RL10 engines have ignited with full thrust!

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

T+plus 5 minutes, 1 second. The 82-foot long first stage has been jettisoned from the Centaur upper stage to fall into the ocean below.

2321 GMT (7:21 p.m. EDT)

T+plus 4 minutes, 56 seconds. The sustainer engine on first stage has shut down, ending a flight history of 576 launches for Rocketdyne-powered Atlas vehicles dating back over 40 years. All future Atlas rockets will use the Russian RD-180 powerplant.

2321 GMT (7:21 p.m. EDT)

T+plus 4 minutes, 20 seconds. The Atlas vehicle is flying on course for its northeasterly heading. The rocket is 76 miles in altitude, 241 miles east of pad 36A, traveling at 7,500 mph.

2320 GMT (7:20 p.m. EDT)

T+plus 3 minutes, 35 seconds. The Atlas rocket's 14-foot diameter nose cone has been jettisoned in two halves. It is no longer needed to protect the NRO satellite during flight through the atmosphere.

2320 GMT (7:20 p.m. EDT)

T+plus 3 minutes. Atlas is now in the sustainer solo phase of flight. This is the firing of the center engine of the Atlas vehicle to consume the remaining fuel in the first stage.

2319 GMT (7:19 p.m. EDT)

T+plus 2 minutes, 52 seconds. After reaching 5.0 g's of axial acceleration, the booster engines have shut down on the first stage. The bottom section of the rocket containing these two outer engine nozzles then separated. This is known as booster package jettison, a trademark of Atlas vehicles dating back decades. But with this final flight of the Atlas 2-series, we have just seen the last booster package jettison. All future launches of Atlas 3 and 5 rockets do not employ such a design with their Russian-made RD-180 engines.

2319 GMT (7:19 p.m. EDT)

T+plus 2 minutes. Having burned all their propellant, the air-lit ATK Thiokol solid rocket boosters have separated from the Atlas rocket. This completes 100 percent success rate during 30 flights for these solids on Atlas.

The vehicle is now riding the power of its Rocketdyne MA-5A engine system.

2318 GMT (7:18 p.m. EDT)

T+plus 90 seconds. Chamber pressures on the air-lit boosters are peaking out.

2318 GMT (7:18 p.m. EDT)

T+plus 83 seconds. The two spent ground-started solid rocket boosters have separated from the Atlas 2AS rocket's first stage to fall into the Atlantic Ocean. The two-air lit boosters continue to fire along with the first liquid-fueled engines.

2318 GMT (7:18 p.m. EDT)

T+plus 61 seconds. The two air-lit solid rocket boosters mounted to the Atlas first stage have ignited as the two ground-lit motors burn out. The spent booster casings will be jettisoned in a few moments once the rocket flies within a preset drop zone.

2317 GMT (7:17 p.m. EDT)

T+plus 40 seconds. Chamber pressures on the ground-lit boosters are peaking out. All systems are looking good.

2317 GMT (7:17 p.m. EDT)

T+plus 10 seconds. The Atlas 2AS vehicle has cleared the tower at pad 36A, becoming the final Atlas to fly from the historic complex that has been in service since 1962.

2317 GMT (7:17 p.m. EDT)

LIFTOFF! Lockheed Martin's last Atlas 2-series vehicle rockets away from Cape Canaveral to deliver a classified U.S. national security spacecraft into orbit!

2316 GMT (7:16 p.m. EDT)

T-minus 31 seconds. The launch sequence has been activated.

In the next few seconds the liquid hydrogen and liquid oxygen vent valves will be locked and the flight data recorders will be readied. The engine ignition sequence will begin at T-minus 2.4 seconds.

2316 GMT (7:16 p.m. EDT)

T-minus 1 minute. Engines are being verified ready for flight. The final status checks of the propellant and pneumatic systems are upcoming to confirm the Atlas and Centaur stages are "go" for launch.

In the past minute, the inertial navigation unit was launch enabled, liquid hydrogen tanking was secured, fuel tank pressures were reported stable and the ignition enable switch was closed.

2315 GMT (7:15 p.m. EDT)

T-minus 1 minutes, 20 seconds. The solid rocket boosters were armed.

2315 GMT (7:15 p.m. EDT)

T-minus 1 minutes, 30 seconds. Once the rocket lifts off, it will head on a northeasterly trajectory up the U.S. eastern seaboard. The Atlas will deliver its classified National Reconnaissance Office payload into a highly inclined orbit. For a track of today's launch, see a map here.

2315 GMT (7:15 p.m. EDT)

T-minus 1 minutes, 45 seconds. The Centaur upper stage has transferred to internal power and the flight termination system is now armed.

2315 GMT (7:15 p.m. EDT)

T-minus 2 minutes. The solid rocket booster fire commands have been enabled and the vehicle's inadvertent separation destruct safety system has been armed.

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

T-minus 2 minutes, 15 seconds. Pressurization of the Atlas/Centaur vehicle has started. Tanks now being brought to proper pressure levels for flight.

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

T-minus 2 minutes, 30 seconds. Atlas first stage topping is being secured.

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

T-minus 2 minutes, 50 seconds. The NRO spacecraft has gone to internal power for launch.

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

T-minus 3 minutes. The launch pad weather system and the Centaur pneumatics are being reported ready.

2313 GMT (7:13 p.m. EDT)

T-minus 4 minutes. The Atlas first stage is transitioning to power.

2312 GMT (7:12 p.m. EDT)

T-minus 4 minutes, 20 seconds. The flight termination system is switching from ground-supplied power to internal batteries.

2312 GMT (7:12 p.m. EDT)

T-minus 4 minutes, 45 seconds. The water system is being readied for activation at launch pad 36A. Water will flood the pad to suppress the sound produced at liftoff and protect the ground support systems.

2312 GMT (7:12 p.m. EDT)

T-minus 5 minutes and counting! The countdown is running again for launch of Lockheed Martin's 30th and final Atlas 2AS rocket. The booster is set for liftoff at 7:17 p.m. EDT from pad 36A at Cape Canaveral Air Force Station in Florida for a 74-minute flight to place a classified craft into space for the U.S. National Reconnaissance Office. The NRO is the government agency responsible for the U.S. fleet of spy satellites.

2311 GMT (7:11 p.m. EDT)

Standing by to pick up the countdown in one minute.

2310 GMT (7:10 p.m. EDT)

"Mission is 'go' for launch," the NRO mission director has announced.

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

Lockheed Martin launch director Adrian Laffitte has given his "go."

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

The launch conductor has polled the launch team for readiness to continue the countdown. No technical or weather problems were reported!

2307 GMT (7:07 p.m. EDT)

Liftoff is now 10 minutes away.

2304 GMT (7:04 p.m. EDT)

The anomaly team has concurred that the first stage liquid oxygen tank is topped off. The slow rate to reach flight level is not a constraint for launch.

2303 GMT (7:03 p.m. EDT)

Weather is still "go."

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

The Atlas first stage liquid oxygen tank has finally reached flight level.

2259 GMT (6:59 p.m. EDT)

Management will conduct polls of the launch team at 7:09 p.m. before giving final approval to resume the countdown at 7:12 p.m. for liftoff five minutes later.

2257 GMT (6:57 p.m. EDT)

Now 20 minutes from the new target launch time of 7:17 p.m. EDT. If the Atlas rocket cannot lift off then, the mission must be delayed another day as the available launch window will close.

The launch team is still working to get the Atlas first stage liquid oxygen tank topped off.

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

The weather continues to remain acceptable for launch.

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

NEW LAUNCH TIME. Officials have decided to delay liftoff until 7:17 p.m. EDT (2317 GMT), which is the end of today's available launch window.

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

The Complex 36 Blockhouse escape tunnel doors are now being sealed.

2244 GMT (6:44 p.m. EDT)

The upper stage liquid hydrogen tank has reached flight level.

2243 GMT (6:43 p.m. EDT)

NEW LAUNCH TIME. To give the launch team some additional time to catch from the earlier countdown delays to replace some valves at the pad, liftoff is being pushed back 10 minutes to 6:59 p.m. EDT.

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

Weather remains "go." However, a new launch time has yet been announced.

2241 GMT (6:41 p.m. EDT)

The launch team is adjusting a valve setting in an effort to speed up the first stage liquid oxygen topping rate.

2239 GMT (6:39 p.m. EDT)

Engineers are looking at a lower-than-normal first stage liquid oxygen topping rate.

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

It appears this hold will be lengthened 15 minutes. That would put launch time at 7:04 p.m. However, that time has not been officially set.

2237 GMT (6:37 p.m. EDT)

Liftoff may be delayed a few minutes. Standing by for official word.

2234 GMT (6:34 p.m. EDT)

Now 15 minutes from launch. All systems remain "go."

2229 GMT (6:29 p.m. EDT)

The Centaur hydrogen tank is now 97 percent full, heading to flight level.

2229 GMT (6:29 p.m. EDT)

T-minus 5 minutes and holding. Clocks has entered the final planned hold in the countdown. During this time, final readiness polls of the launch team will be performed to verify there are no problems before entering the last five minutes of the count. Liftoff remains targeted for 6:49 p.m. EDT (2249 GMT), and weather is still acceptable.

2224 GMT (6:24 p.m. EDT)

The Atlas liquid oxygen tank has reached the 98 percent level where it is being maintained. Topping to 100 percent will be completed shortly.

2224 GMT (6:24 p.m. EDT)

T-minus 10 minutes and counting. Countdown clocks are ticking down to the T-minus 5 minute mark where a planned 15-minute hold will occur. Launch remains targeted for 6:49 p.m. EDT. The clouds and storms to the west of Cape Canaveral are staying clear of the launch site.

2223 GMT (6:23 p.m. EDT)

The Centaur hydrogen tank is 70 percent full.

2219 GMT (6:19 p.m. EDT)

Weather conditions remain "go" with 30 minutes remaining in the countdown.

2215 GMT (6:15 p.m. EDT)

Fueling operations continue. The first stage liquid oxygen tank has reached the 80 percent mark and the Centaur liquid hydrogen tank is 30 percent full.

2211 GMT (6:11 p.m. EDT)

Filling of the Centaur liquid hydrogen fuel tank has reached the 10 percent mark.

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

The flight termination system self test is complete.

2209 GMT (6:09 p.m. EDT)

Topping of the Centaur liquid oxygen tank to flight level has been completed. But as the countdown proceeds, the tank will be replenished to replace the cryogenic liquid oxygen that naturally boils away.

Forty minutes until the window opens.

2208 GMT (6:08 p.m. EDT)

The first stage liquid oxygen tank is half full.

2207 GMT (6:07 p.m. EDT)

With the liquid hydrogen system chilldown complete, officials have given the "go" to load the super-chilled fuel into the Centaur upper stage. The cryogenic propellant will be consumed with liquid oxygen by the stage's Pratt & Whitney-made RL10 engines to propel the NRO spacecraft into the targeted orbit tonight.

2206 GMT (6:06 p.m. EDT)

To recap the weather, there are storms to the northwest. But the launch weather team is hopeful the rain and clouds will stay far enough away from pad 36A to permit liftoff. There is a 70 percent chance that the weather will be GO for launch today.

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

The first stage liquid oxygen tank is 20 percent full.

And an inhibited self test of the rocket's flight termination system is beginning. The FTS would be used to destroy the vehicle in the event of a malfunction during launch.

2153 GMT (5:53 p.m. EDT)

The weather situation is improving! Meteorologists are briefing mission managers on the current and forecast conditions. There are no rules being violated and the probability of breaking the criteria during the launch window is now just 30 percent. It had been 60 percent.

Meanwhile, the "go" has now been given to start loading of the Atlas first stage liquid oxygen tank.

2151 GMT (5:51 p.m. EDT)

Some countdown activities have been delayed while a small team was sent into the launch pad to replace a couple of valves. That work has been completed and the Atlas pneumatic system charging is occurring normally now.

With everyone back inside the Complex 36 Blockhouse again, the door is being sealed, protecting the 120-member launch team. The blockhouse is located just 1,400 feet away from the Atlas 2AS rocket at pad 36A, and serves as the control center for the countdown to launch.

2149 GMT (5:49 p.m. EDT)

Now 60 minutes from the opening of today's launch opportunity.

2148 GMT (5:48 p.m. EDT)

The Centaur liquid oxygen tank has reached the 95 percent full level where it is being maintained. Topping to 100 percent will be completed shortly.

2147 GMT (5:47 p.m. EDT)

The repair crew is leaving the launch pad, having completed their work.

With the hazard area being cleared again, the chilldown conditioning of liquid hydrogen propellant lines at pad 36A is starting to prepare the plumbing for transferring the Minus-423 degree F fuel into the rocket.

2140 GMT (5:40 p.m. EDT)

The Centaur liquid oxygen tank has reached the 80 percent mark.

The team replacing some valves for the Atlas pneumatic system continues its work at the base of pad 36A.

The leading edge of rain from the closest thunderstorm is 30 miles to the west-northwest.

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

The final alignment of the Atlas rocket's inertial navigation guidance computer has been completed. The flight control system final preps have begun.

2128 GMT (5:28 p.m. EDT)

The Centaur liquid oxygen loading continues slowly with the tank now reaching the 60 percent point. Meanwhile, the special repair crew is at the pad.

2118 GMT (5:18 p.m. EDT)

The Centaur liquid oxygen tank is now 40 percent full.

Meteorologists are keeping a close watch on thunderstorms to the northwest of the Cape. None of the launch weather rules are being violated so far.

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

The flow-rate for Centaur liquid oxygen loading will be slowed to keep the system thermally conditioned while the small crew returns to pad 36A to replace a couple of valves.

Filling of the Atlas first stage with liquid oxygen and Centaur liquid hydrogen tanking will be delayed until after the workers complete the valve job and clear the hazard area.

The countdown is structured to accommodate these sorts of delays without impacting the scheduled launch time.

2108 GMT (5:08 p.m. EDT)

A problem has been reported with the Atlas pneumatic system. A special crew will be dispatched to replace valves in the system charging line to correct the problem.

Meanwhile, the Centaur liquid oxygen tank is now 10 percent full.

2102 GMT (5:02 p.m. EDT)

Chilldown conditioning of the liquid oxygen transfer lines at pad 36A is complete. And the "go" has now been given to start filling the Centaur upper stage with its supply of super-cold cryogenic oxidizer.

The liquid oxygen -- chilled to Minus-298 degrees F -- will be consumed during the launch by the Centaur's twin RL10 engines along with liquid hydrogen to be pumped into the stage later in the countdown.

2055 GMT (4:55 p.m. EDT)

The safe-and-arm test of the flight termination system has been completed.

2050 GMT (4:50 p.m. EDT)

Safety officials have confirmed that the danger area around the launch pad is cleared of all personnel. This allows the "chilldown" procedure to start for thermal conditioning of the liquid oxygen fuel lines at pad 36A in advance of loading the Centaur upper stage.

Also at this time, the Centaur pneumatic bottle charging and the engine gaseous helium chilldown operations are starting.

2049 GMT (4:49 p.m. EDT)

T-minus 105 minutes and counting. The countdown has resumed after the planned 30-minute hold.

The count will continue to T-minus 5 minutes where a planned 15-minute built-in hold is scheduled. Launch of the Atlas 2AS rocket with the secret NRO cargo remains targeted for 6:49 p.m. EDT.

2045 GMT (4:45 p.m. EDT)

From his console inside the Complex 36 Blockhouse, the Lockheed Martin launch conductor has performed his pre-fueling poll of the launch team. Atlas launch director Adrian Laffitte then gave a "ready" status, followed by the NRO mission director. There were no constraints reported.

Cryogenic liquid oxygen and liquid hydrogen propellants will be pumped into the Atlas and Centaur stages beginning at 5:03 p.m.

The pad has been configured for launch and the final workers are clearing the hazard area.

2042 GMT (4:42 p.m. EDT)

A readiness poll for fueling the Atlas rocket is coming up in two minutes.

2034 GMT (4:34 p.m. EDT)

The countdown has been holding for 15 minutes. Weather remains "go" and no technical issues are being reported by Lockheed Martin.

Read our earlier status center coverage.

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