BY JUSTIN RAY

Follow the countdown and launch of the Lockheed Martin Atlas 3B rocket with the AsiaSat 4 communications satellite. Reload this page for the very latest on the mission.

2336 GMT (7:36 p.m. EDT)

The Centaur liquid hydrogen and Atlas first stage liquid oxygen tanks are now reported at flight level. Centaur oxygen tanking reach flight level earlier, meaning the rocket is now fully fueled for launch.

But given the cryogenic nature of the liquid oxygen and liquid hydrogen loaded into the rocket tonight, the supplies naturally boil away and the propellants have to be replenished during the countdown.

2334 GMT (7:34 p.m. EDT)

Launch weather officer Jim Sardonia has just briefed mission managers. "Everything is looking good." He says all weather rules are currently "go" for launch and expected to remain that way. The cloudiness in the area is not a concern and winds have dropped off dramatically to just 8 to 14 knots -- well below the 25-knot limit.

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

The Centaur hydrogen tank is now 97 percent, heading to flight level. Topping of the Atlas liquid oxygen tank is underway.

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

An inhibited self test of the rocket's Flight Termination System is starting. The FTS would be used to destroy the vehicle in the event of a malfunction during launch.

And a short time ago, interrogation checks were performed to verify the rocket's C-band beacon is ready for use to track the vehicle during flight.

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

The Centaur liquid oxygen tank has reached flight level. Centaur liquid hydrogen tank is now at 80 percent.

2314 GMT (7:14 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.

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

Now one hour away from the scheduled launch time.

Fueling of the rocket with super-cold rocket fuel is continuing as planned. The Centaur upper stage hydrogen tank is nearing the 10 percent level; the Atlas first stage liquid oxygen tank is over 80 percent; and the Centaur liquid oxygen tank topping is underway.

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

The Atlas first stage liquid oxygen tank has reached 50 percent. Meanwhile, the Centaur engine gaseous helium chilldown has started.

2301 GMT (7:01 p.m. EDT)

The liquid hydrogen chilldown is now complete and the "go" has been given 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 RL-10 engine to propel the AsiaSat 4 spacecraft into the targeted geosynchronous transfer orbit tonight.

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

The rocket's first stage is icing over as the super-cold liquid oxygen continues to flow into the vehicle. The tank is just over 30 percent filled.

2255 GMT (6:55 p.m. EDT)

The Atlas liquid oxygen tank is now at the 10 percent level. Centaur liquid oyxgen topping to flight level has started.

2247 GMT (6:47 p.m. EDT)

The Centaur liquid oxygen tank has reached 95 percent full level where it is being secured. Topping to 100 percent will be completed shortly. As the countdown proceeds, the tank will be replenished to replace the cryogenic liquid oxygen that naturally boils away.

And the "go" has now been given to commence loading of the Atlas first stage liquid oxygen tank.

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

The chilldown conditioning of liquid hydrogen propellant lines at pad 36B is now starting to prepare the plumbing for transferring the Minus-423 degree F fuel into the rocket.

Also at this time the door of the Complex 36 Blockhouse is being sealed, protecting the 120-member launch team. The Blockhouse is located just 1,400 feet away from the Atlas 3 rocket at pad 36B, and serves as the control center for the countdown to launch.

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

Launch of the Atlas 3B rocket is now 90 minutes away. The Centaur oxygen tank is half-full.

2231 GMT (6:31 p.m. EDT)

The Centaur liquid oyxgen tank has reached the 20 percent mark in these early minutes of fueling activities.

2222 GMT (6:22 p.m. EDT)

Chilldown conditioning of the liquid oxygen transfer lines at pad 36B is complete. The "go" has now been given to start filling the Centaur upper stage with its 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 single RL-10 engine along with liquid hydrogen to be pumped into the stage a little later in the countdown.

2220 GMT (6:20 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.

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

The danger area around the launch pad has just been verified cleared of all personnel. This allows the "chilldown" procedure to start for thermal conditioning of the liquid oxygen fuel lines at pad 36B in advance of loading the Centaur upper stage.

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

T-minus 105 minutes and counting. The countdown is running again after the planned half-hour hold.

The countdown will continue to T-minus 5 minutes where a planned 15-minute built-in hold is scheduled. Launch of the Atlas 3B rocket with AsiaSat 4 is targeted for two hours from now.

Engineers are assessing an error message from the rocket's inertial navigation unit. It is something that will have to be resolved before launch can occur, officials said. However, the analysis will not delay fueling operations.

2204 GMT (6:04 p.m. EDT)

A readiness check has been performed of the launch team by Lockheed Martin launch conductor Ed Christiansen in preparation to begin fueling the Atlas rocket. No problems were reported. Launch director Adrian Laffitte also gave a "ready" status.

At launch pad 36B, workers have completed securing work following mobile service tower rollback. Christiansen instructed them to clear the area.

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

Now 10 minutes remaining in this hold at T-minus 105 minutes. Once the countdown resumes, work to load cryogenic liquid oxygen and liquid hydrogen propellants into the Atlas 3B rocket will begin.

2145 GMT (5:45 p.m. EDT)

The Air Force has announced there is one Collision Avoidance period, or COLA, that will prohibit liftoff for a few minutes during today's launch window. The COLA extends from 8:27:37 to 8:36:46 p.m. EDT.

COLA cutouts occur to ensure the rocket isn't launched on a course that would take it too close to an object already orbiting in space.

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

T-minus 105 minutes and holding. Clocks have entered a planned 30-minute built-in hold period for the Atlas countdown today at Cape Canaveral Air Force Station, Florida.

The count has 45 minutes of holds scheduled over the course the day that will lead to liftoff at 8:08 p.m. EDT (0008 GMT). A second and final hold is planned at T-minus 5 minutes for 15 minutes. The holds are designed to give the launch team a window of time to work any problems that could arise.

2120 GMT (5:20 p.m. EDT)

The mobile service tower is now clear of the rocket and continuing to roll to the parking location for tonight's launch.

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

With liftoff exactly three hours away, the "go" has been given to start rolling the mobile service tower away from the Atlas 3 rocket and into the launch position.

The tower is used to erect the rocket on the launch pad, provide access for workers to all areas of the vehicle and give protection from the weather. It is electrically driven on four-wheel assemblies.

2053 GMT (4:53 p.m. EDT)

T-minus 150 minutes and counting. "Man stations for Integrated Launch Operations." The countdown is on schedule for today's launch of Lockheed Martin's Atlas 3B rocket carrying the AsiaSat 4 telecommunications spacecraft.

There are two holds, lasting for a total of 45 minutes, built into the countdown at T-minus 105 minutes and T-minus 5 minutes. Liftoff is targeted for 8:08 p.m. EDT.

The countdown is being controlled from the Complex 36 Blockhouse where the 120-member team has assembled to oversee the activities leading up to liftoff of this Atlas 3B rocket. The senior management team is housed in the Atlas 5 Spaceflight Operations Center (ASOC), a departure from the past use of NASA's Hangar AE Mission Directors Center for Atlas 2 and 3 rocket launches.

Launch weather officer Jim Sardonia just completed a briefing for officials in advance of mobile service tower rollback. Weather system that caused the problems with clouds and winds yesterday has moved away from Florida.

The winds have diminished from what has been experienced over the past day here at the Cape, with gusts well below the 28-knot limit for retracting the service structure. Due to strong winds, the move was delayed into the countdown during yesterday's launch attempt.

The launch time limit is 25 knots. Sardonia says the winds are trending downward as evening approaches and should remain below that threshold. But the situation will be watched closely for any gusts.

The winds aloft, which ultimately forced yesterday's attempt to be scrubbed, are persistent today. Rapidly changing conditions with the upper level winds meant engineers could not generate a guidance program for the rocket before the close of the day's launch window.

Besides a possible wind gust at the pad about 25 knots, the only other concern for tonight will be cumulus clouds. The weather team will be examining the clouds over the launch site to ensure they do not violate the Cumulus Cloud Rule.

Overall there is an 80 percent chance of acceptable weather conditions during the launch window of 8:08 to 9:20 p.m. EDT.

2000 GMT (4:00 p.m. EDT)

Standard countdown activities have been underway this afternoon in the Complex 36 blockhouse and at pad 36B.

The Integrated Launch Operations -- the final portion of the countdown in which all members of the launch team participate -- will start at 4:53 p.m. EDT (2053 GMT). Retraction of the mobile service tower from around the rocket is slated for 5:08 p.m. EST.

Countdown clocks will enter a planned 30-minute hold at the T-minus 105 minute mark starting at 5:38 p.m. EDT. During this time the launch team will have a chance to catch up on any work that might be running behind schedule.

Fueling operations will commence at 6:22 p.m. EDT with super-cold liquid oxygen flowing into the Centaur upper stage. Loading of liquid oxygen into the Atlas booster stage should start at 6:43 p.m. The final segment of fueling will begin at 6:59 p.m. when liquid hydrogen is pumped into the Centaur. The Atlas stage was previously fueled with its supply of RP-1 kerosene propellant.

A final planned hold is scheduled at T-minus 5 minutes for 15 minutes in duration. If there are no problems standing in the way of liftoff, the countdown will resume at 8:03 p.m. for an on-time launch.

1600 GMT (12:00 p.m. EDT)

The latest weather forecast calls for an 80 percent chance of acceptable conditions tonight. Clouds and winds are the main concerns going into this launch opportunity.

Lockheed Martin says the post-scrub operations went smoothly last night. The rocket was drained of its liquid hydrogen and liquid oxygen cryogenics. There are no technical problems being reported with the Atlas 3 launch vehicle or AsiaSat 4 payload.

1518 GMT (11:18 a.m. EDT)

It's a new day and a new countdown is beginning for the launch of Atlas 3 and the AsiaSat 4 communications satellite from Cape Canaveral Air Force Station, Florida. Liftoff is scheduled for 8:08 p.m. EDT at the opening of a 72-minute window extending to 9:20 p.m. EDT.

0315 GMT (11:15 p.m. EDT Thurs.)

Weather officer Jim Sardonia's forecast for Friday night's launch opportunity is posted here.

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

The post-scrub safing operations for the Atlas vehicle are underway. Preparations are now being made to roll the mobile service tower back around the rocket.

Here is the call from the management team recommending the scrub tonight:

"Due to the doppler data being so dramatically different from the balloon data, and having been consistent for the last 15-20 minutes, we are not able to produce a design to fly the vehicle through this atmosphere. Conditions have changed enough to warrant a need for a new design. We don't have time to put another balloon (in the air). There is a balloon in the air now but it won't be high enough to produce a new design to load up onto the vehicle before the close of the window. I recommend we secure this operation for this evening and try again at our earliest opportunity."

Watch this page for live updates during Friday's launch attempt.

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

SCRUB! Launch of the Atlas 3B rocket and AsiaSat 4 has been postponed 24 hours due to high-altitude winds. The atmospheric conditions have changed such that a new launch profile cannot be generated in the time remaining in today's window.

Tomorrow's launch window extends from 8:08 to 9:20 p.m. EDT (0008-0120 GMT).

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

Officials recommending a scrub due to winds aloft.

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

Winds aloft are the current problem being addressed. Engineers are concerned that the weather balloon and the doppler profiler data are too varied.

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

HOLD EXTENDED! The launch has been delayed another 10 minutes to further examine the upper level wind situation. Launch is now no sooner than 9:07 p.m. EDT. Today's available window extends 14 minutes beyond that.

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

The Lockheed Martin final readiness poll of the entire launch team was just performed by Launch Conductor Ed Christiansen in the Complex 36 Blockhouse. No problems reported. Management poll will now follow.

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

The launch weather officer says there is a wide difference being noted in the upper level winds between the last weather balloon and the doppler profiler, including a 30-knot difference at 20,000 feet and a 40 degree difference in direction below that.

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

Launch is now 12 minutes away. Discussion underway about the upper level winds.

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

The Jolly choppers used by the Range will be out of the restricted airspace in time to support liftoff at 8:57 p.m. EDT, officials report.

0042 GMT (8:42 p.m. EDT Thurs.)

The Range is checking to see when the hazard area will be clear.

0042 GMT (8:42 p.m. EDT Thurs.)

Weather is go for launch! The Thick Cloud Rule is no longer being violated, the weather officer reports.

0040 GMT (8:40 p.m. EDT Thurs.)

Weather still being watched closely. Another poll of the launch team and officials is coming up in a few minutes to determine if liftoff can occur at 8:57 p.m.

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

HOLD EXTENDED. Ten more minutes have been added into the hold. Launch time is now targeted for 8:57 p.m. EDT. That is predicated on the weather and Range being cleared.

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

The Atlas fuel fill is reported complete.

0032 GMT (8:32 p.m. EDT Thurs.)

The Range says unofficially it can support an 8:50 p.m. launch time.

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

HOLD EXTENDED. Another 10 minutes have been added to the hold, delaying liftoff to no sooner than 8:47 p.m. EDT. Weather remains "no go" for launch. The launch weather officer, Jim Sardonia, says it will be 10 minutes from right now before the clouds conditions could be acceptable.

Rockets aren't permitted to fly through thick clouds due to concerns that the booster would trigger a lightning strike.

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

It is now beginning to sprinkle at the press site located a couple miles from launch pad 36B.

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

NEW LAUNCH TIME. Liftoff has been delayed to 8:37 p.m. EDT because of unacceptable cloud conditions over the launch site. The Thick Cloud Rule is being violated at present.

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

Range is "no go" for launch due to the Thick Cloud Rule. Officials are estimating 15 minutes for this condition.

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

Now 10 minutes from the rescheduled liftoff time of Atlas 3 from Cape Canaveral, Florida.

0016 GMT (8:16 p.m. EDT Thurs.)

The fuel fill sequence for the Russian-made RD-180 engine of the first stage has started.

0016 GMT (8:16 p.m. EDT Thurs.)

The weather team is verifying a cloud over the Cape is not violating the Thick Cloud Rule.

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

Lockheed Martin says that cloud that was of concern should be moved through the area -- and the weather aircraft clear -- for the 8:27 p.m. EDT launch time. However, there are some other clouds being watched. Tonight's window extends until 9:21 p.m. EDT.

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

NEW LAUNCH TIME. The launch team in the blockhouse is setting up for an 8:27 p.m. EDT liftoff time. That takes into account the RD-180 fuel fill operations.

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

Lockheed Martin is targeting 8:20 p.m. EDT for launch. The aircraft should be clear by then.

0006 GMT (8:06 p.m. EDT Thurs.)

The fuel fill sequence has been terminated for the moment.

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

Launch is on hold at the moment. A new liftoff time is not yet set. Officials are tracking a cloud headed for the pad that is of concern and the weather aircraft checking the cloud is in the launch danger area.

0004 GMT (8:04 p.m. EDT Thurs.)

HOLD EXTENDED. Range is no go to resume the count due to the weather aircraft in the restricted airspace.

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

Launch weather officer Jim Sardonia says the weather aircraft is needed to investigate a cloud headed for the pad. With that plane 4 miles from the pad, the Range is no go for launch.

0002 GMT (8:02 p.m. EDT Thurs.)

The Lockheed Martin final readiness poll of the entire launch team was just performed by Launch Conductor Ed Christiansen in the Complex 36 Blockhouse. Everyone reported "go" for launch except for the Range due to weather reconnaissance aircraft in the danger area.

Officials had delayed liftoff 10 minutes but have since scrapped that plan when it was determined the extra time wasn't needed to work a technical issue.

THURSDAY, APRIL 10, 2003
2358 GMT (7:58 p.m. EDT)


The fuel fill sequence for the RD-180 main engine has started. Liftoff is set to go at 8:09 p.m. EDT. The earlier spacecraft issue has apparently been resolved in time so the launch wouldn't have to be delayed tonight.

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

Launch director Adrian Laffitte just instructed the launch team to remove that extra 10 minutes from the hold, putting liftoff back at 8:09 p.m. EDT! Again, launch is back on schedule!

2355 GMT (7:55 p.m. EDT)

HOLD EXTENDED. This hold at T-minus 5 minutes is being lengthened by 10 minutes -- delaying liftoff to 8:19 p.m. EDT -- to give the payload team more time to get AsiaSat 4 switched to internal power for launch.

2354 GMT (7:54 p.m. EDT)

Now 15 minutes away from launch. The team is looking to delay the "fuel drop" sequence for the RD-180 main engine during this hold due to an issue with the spacecraft.

2351 GMT (7:51 p.m. EDT)

Officials report the earlier discussion concerning the launch holddown pressure measurements is not a constraint at this time.

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

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

2349 GMT (7:49 p.m. EDT)

T-minus 5 minutes and holding. The countdown has entered this final planned hold. The pause is scheduled to last 15 minutes. During this time, the launch team will verify all systems are ready for flight. Management will also conduct a series of polls before giving final approval to continue with the countdown.

Liftoff is targeted for 8:09 p.m. EDT. Weather conditions are expected to be acceptable for an on-time liftoff.

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

Coming up on the built-in hold in three minutes. Engineers are discussing pressure levels in the rocket holddown system.

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

The AsiaSat 4 spacecraft atop the Atlas 3 rocket is now switching to its internal batteries for launch.

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

T-minus 15 minutes and counting. Countdown clocks are ticking down to the T-minus 5 minute mark where a 15-minute hold will occur. Liftoff still set for 8:09 p.m. EDT.

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

The Centaur liquid hydrogen and Atlas first stage liquid oxygen tanks are now reported at flight level. Centaur oxygen tanking reach flight level earlier, meaning the rocket is now fully fueled for launch. But given the cryogenic nature of the liquid oxygen and liquid hydrogen loaded into the rocket tonight, the supplies naturally boil away and the propellants have to be replenished during the countdown.

2334 GMT (7:34 p.m. EDT)

Launch weather officer Jim Sardonia says winds are within limits and not expected to be a problem at all tonight. However, there are light rain showers and thick clouds to the west and northwest of the Cape that are headed for the launch site. If that line moves over the pad, it would be violation of the launch rules. Sardonia says conditions are acceptable at the moment and should be "go" through the first 20 minutes of the window. After that, conditions are very iffy for the remainder of tonight's 72-minute window.

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

Topping of the Atlas liquid oxygen tank is underway.

An inhibited self test of the rocket's Flight Termination System is starting. The FTS would be used to destroy the vehicle in the event of a malfunction during launch.

And a short time ago, interrogation checks were performed to verify the rocket's C-band beacon is ready for use to track the vehicle during flight.

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

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

2319 GMT (7:19 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.

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

Centaur liquid hydrogen tank is now at 70 percent. The liquid oxygen tank has reached flight level.

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

Now one hour away from the scheduled launch time. There are no problems being reported by the launch team.

Fueling of the rocket with super-cold rocket fuel is continuing as planned. The Centaur upper stage hydrogen tank is past the 10 percent level; the Atlas first stage liquid oxygen tank is over 70 percent; and the Centaur liquid oxygen tank has been filled.

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

The liquid hydrogen chilldown is now complete and the "go" has been given 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 RL-10 engine to propel the AsiaSat 4 spacecraft into the targeted geosynchronous transfer orbit tonight.

2302 GMT (7:02 p.m. EDT)

The Atlas first stage liquid oxygen tank is now at 40 percent.

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

The first stage liquid oxygen tank has been filled with just over 20 percent of its capacity. The rocket's shiny exterior is turning a frosty white as a thin layer of ice forms from the super-cold liquid oxygen.

2256 GMT (6:56 p.m. EDT)

Centaur liquid oyxgen topping to flight level is starting. And the Atlas liquid oxygen tank is now at the 10 percent level.

2247 GMT (6:47 p.m. EDT)

The Centaur liquid oxygen tank has reached 95 percent full level where it is being secured. Topping to 100 percent will be completed shortly. As the countdown proceeds, the tank will be replenished to replace the cryogenic liquid oxygen that naturally boils away.

And the "go" has now been given to commence loading of the Atlas first stage liquid oxygen tank.

2245 GMT (6:45 p.m. EDT)

The mobile service tower has arrived in its parked position for tonight's launch. Meanwhile, the Centaur liquid oxygen tank is now 90 percent full.

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

The chilldown conditioning of liquid hydrogen propellant lines at pad 36B is now starting to prepare the plumbing for transferring the Minus-423 degree F fuel into the rocket.

Also at this time the door of the Complex 36 Blockhouse is being sealed, protecting the 120-member launch team. The Blockhouse is located just 1,400 feet away from the Atlas 3 rocket at pad 36B, and serves as the control center for the countdown to launch.

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

Launch of the Atlas 3B rocket is now 90 minutes away. The initial portions of fueling operations continue with the Centaur liquid oyxgen tank having reached the 50 percent mark.

Also, the final alignment of the Atlas rocket's inertial navigation guidance computer was completed a few minutes ago. The flight control system final preps have begun.

2230 GMT (6:30 p.m. EDT)

As the service tower slowly moves away from the Atlas 3B rocket, the launch team reports the Centaur liquid oxygen tank is now 10 percent full.

2225 GMT (6:25 p.m. EDT)

The wind conditions have improved at Cape Canaveral as expected, clearing the way to retract the mobile service tower to its launch position. Launch conductor Ed Christiansen has given approval to the "tower driver" to begin rolling back the structure via remote control.

2222 GMT (6:22 p.m. EDT)

Chilldown conditioning of the liquid oxygen transfer lines at pad 36B has been completed and the launch team is now beginning to fill the Centaur upper stage with its 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 single RL-10 engine along with liquid hydrogen to be pumped into the stage a little later in the countdown.

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

With the danger area around the complex verified clear, the "chilldown" procedure is starting to thermally condition the liquid oxygen fuel lines at pad 36B in advance of loading the Centaur upper stage.

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

T-minus 105 minutes and counting. Countdown clocks have picked up as scheduled following the planned half-hour hold.

The countdown will continue to T-minus 5 minutes where a planned 15-minute built-in hold is scheduled. Launch of the Atlas 3B rocket with AsiaSat 4 is targeted for two hours from now.

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

Lockheed Martin launch conductor Ed Christiansen has just polled the launch team for a readiness check in preparation to begin fueling the Atlas rocket. No problems were reported. Launch director Adrian Laffitte then gave his "ready" call.

Meanwhile, technicians at the pad have announced that the complex securing work is now complete. Christiansen instructed them to clear the area. The mobile service tower will be rolled into the launch position via remote control later in the countdown once the winds ease to acceptable limits.

2154 GMT (5:54 p.m. EDT)

Now half-way through this 30-minute scheduled hold at T-minus 105 minutes. Once the countdown resumes, activities will be focused on loading cryogenic liquid oxygen and liquid hydrogen propellants into the Atlas 3B rocket.

2142 GMT (5:42 p.m. EDT)

The launch team is starting the final alignment of the vehicle's guidance computer.

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

T-minus 105 minutes and holding. Clocks have entered a planned 30-minute built-in hold period for the Atlas countdown today at Cape Canaveral Air Force Station, Florida.

The count has 45 minutes of holds scheduled over the course the day that will lead to liftoff at 8:09 p.m. EDT (0009 GMT). A second and final hold is planned at T-minus 5 minutes for 15 minutes. The holds are designed to give the launch team a window of time to work any problems that could arise.

In addition to the winds, weather officials are also watching some showers moving from the central part of Florida toward the eastern coast. But the hope is conditions will permit liftoff during tonight's 72-minute launch window.

The Air Force has announced there are no COLA, or Collision Avoidance periods, that will prohibit launch during any of the window. The COLA cutouts occur to ensure the rocket isn't launched on a course that would take it too close to an object already orbiting in space.

2109 GMT (5:09 p.m. EDT)

Now three hours from liftoff time.

At launch pad 36B, access platforms and equipment inside the mobile service tower have been stowed and technicians have been given a "go" to move the structure into the tangent position.

The tower is used to erect the rocket on the launch pad, provide access for workers to all areas of the vehicle and give protection from the weather. It is electrically driven on four-wheel assemblies.

2057 GMT (4:57 p.m. EDT)

Launch director Adrian Laffitte has just announced that the decision has been made to employ the "tanking in the tower" procedures today, as described in our morning status update below. The winds at launch pad 36B remain gusty this afternoon.

So the pad crews will now move the mobile service tower into the so-called "tangent" position a few feet from its current parked location totally enclosing the Atlas 3 rocket. This will allow the countdown operations to continue as planned today, including fueling the rocket with super-cold propellants. Once the winds decrease to acceptable limits, the tower will be remotely commanded to roll into the launch position a safe distance away from the rocket.

2054 GMT (4:54 p.m. EDT)

T-minus 150 minutes and counting. "Man stations for Integrated Launch Operations." That is the call to the launch team for members to take their positions at Cape Canaveral Air Force Station as the countdown enters the next phase for today's liftoff of the Lockheed Martin Atlas 3B rocket carrying the AsiaSat 4 telecommunications spacecraft.

There are two built-in holds, lasting for a total of 45 minutes, scheduled into the countdown at T-minus 105 minutes and T-minus 5 minutes.

Liftoff remains set for 8:09 p.m. EDT.

The countdown is being controlled from the Complex 36 Blockhouse where the 120-member launch team has assembled to oversee the activities leading up to liftoff of this Atlas 3B rocket. The senior management team is housed in the Atlas 5 Spaceflight Operations Center (ASOC), a departure from the past use of NASA's Hangar AE Mission Directors Center for Atlas 2 and 3 rocket launches.

1900 GMT (3:00 p.m. EST)

Countdown operations are proceeding at pad 36B in preparation for tonight's launch of AC-205, an Atlas 3B rocket with a single-engine Centaur upper stage. This will be the first flight of this specific vehicle configuration.

The ground winds have been blowing upwards of 30 knots over the past couple of hours. However, forecasters say the winds will gradually ease as the sun goes down later this evening.

1700 GMT (1:00 p.m. EST)

Launch weather officer Jim Sardonia issued his launch day forecast a short time ago. See the full forecast here.

1519 GMT (11:19 a.m. EST)

Clocks at Cape Canaveral's Launch Complex 36 begin counting down at this time for tonight's launch of the Lockheed Martin Atlas 3B rocket carrying the AsiaSat 4 communications satellite.

Liftoff is scheduled for 8:09 p.m. EDT (0009 GMT), the opening of a 72-minute launch window that extends until 9:21 p.m. EDT (0121 GMT).

"The team is ready," launch director Adrian Laffitte said at a morning news conference. "We are working no technical issues."

"I am very delighted about the mission today," added Mark Albrecht, the president of Atlas marketing firm International Launch Services. "Things are looking very good."

Air Force meteorologists are predicting a 70 percent chance of meeting the launch weather rules. The chief worry is gusty winds buffeting the Cape area today following the passage of frontal system.

"The only issue it looks like will be the winds," launch weather officer Jim Sardonia told reporters today. "We had a very strong cold front that moved through. You can tell outside the cooler temperatures and the drier conditions. Winds have picked up this morning. We have seen winds out at the Cape up to 22-23 knots at the 90-foot level.

"We do expect those winds to pick up as the sun rises and afternoon goes on. It is the usual diurnal, daily pattern. The winds will peak in the early afternoon hours, about 2-3 p.m.

"We are expecting as the sun goes down, we also expect the winds to slightly decrease -- a down slope in the wind speed at Complex 36."

Winds become a factor shortly after 5 p.m. EDT when the launch pad's protective mobile service tower is scheduled to be rolled away from the Atlas 3 rocket.

"The constraint is 28 knots and I expect the peaks to be very close to that. We could see a few isolated peaks above 28 knots during that time. But most likely I think the winds are going to be between 24 and 26 knots when we get to tower roll," Sardonia said.

If the winds are out of limits at the scheduled tower rollback time, the Atlas team has the ability to clear the pad of all workers so the hazardous countdown activities -- like fueling the rocket -- can begin and then retract the service structure later via remote control.

"We will continue to track the wind. As soon as we see the trend of the wind is below the limit...we will remotely move the tower back to the service position," Laffitte explained.

The so-called "tanking in the tower" procedure of fueling the rocket on-time during the countdown yet with the tower still enclosing the vehicle has been demonstrated successfully in the past.

The rollback could occur as late as the countdown's planned built-in hold at the T-minus 5 minute mark. It will take 8 to 10 minutes to move the tower, Laffitte said.

As for the winds at launch time, there is a 30 percent chance of getting gusts above the allowable constraint. The out-of-bounds limit varies between 25 and 28 knots, depending on the specific direction of the wind, Sardonia said.

Throughout the day today the crews in the Complex 36 blockhouse and at pad 36B will proceed through their standard countdown chores needed to ready the Atlas booster and its "stretched" Centaur upper stage for launch, as well as the ground systems and AsiaSat 4 spacecraft.

Highlights of activities planned, in the order they are scheduled to be performed, include Centaur propulsion launch preps, powering up the rocket's flight control system, Atlas propulsion and hydraulic systems preps, preps of the pad's tower and mobile service structure, performing the flight control operational test, the internal power test of Atlas/Centaur, performing a navigation test of rocket's guidance computer, Centaur engine igniter checks, starting Centaur helium purges and starting liquid hydrogen and liquid oxygen system final preps.

The Integrated Launch Operations -- the final portion of the countdown in which all members of the launch team participate -- will start at 4:54 p.m. EDT (2054 GMT). Retraction of the mobile service tower from around the rocket is slated for 5:09 p.m. EST.

Countdown clocks will enter a planned 30-minute hold at the T-minus 105 minute mark starting at 5:39 p.m. EDT. During this time the launch team will have a chance to catch up on any work that might be running behind schedule.

Fueling operations will commence at 6:23 p.m. EDT with super-cold liquid oxygen flowing into the Centaur upper stage. Loading of liquid oxygen into the Atlas booster stage should start at 6:44 p.m. The final segment of fueling will begin at 7:00 p.m. when liquid hydrogen is pumped into the Centaur. The Atlas stage was previously fueled with its supply of RP-1 kerosene propellant.

A final planned hold is scheduled at T-minus 5 minutes for 15 minutes in duration. If there are no problems standing in the way of liftoff, the countdown will resume at 8:04 p.m. for an on-time launch.

We will provide play-by-play coverage of the countdown on this page beginning at 4:45 p.m. EDT.

THURSDAY, APRIL 10, 2003

Just after sunset tonight along Florida's Space Coast, a Lockheed Martin Atlas 3B rocket is expected to fire off the launch pad carrying a telecommunications satellite to serve the Asia-Pacific region.

Liftoff is scheduled for 8:09 p.m. EDT (0009 GMT) from Cape Canaveral Air Force Station's pad 36B. The day's available window extends to 9:21 p.m. EDT (0121 GMT).

The weather forecast is favorable with only a 30 percent chance of gusty winds posing a problem. See the full forecast here.

Senior managers held their final readiness reviews Wednesday for a last check of launch preparations before starting the countdown this morning.

"Everything is looking very good," Adrian Laffitte, Lockheed Martin's director of Atlas programs at the Cape, said in an interview. "We went through the vehicle, the payload and Range. We are working no technical issues."

Following Tuesday's successful launch of a Titan 4B rocket and Centaur upper stage, teams have been sifting through data to ensure there were no problems that could harm the Atlas 3 mission. The Titan and Atlas launchers feature similar Pratt & Whitney RL-10 engines on the Centaur upper stages of both rockets.

"We have looked at the Titan 4 data. There are no surprises in the data," Laffitte said. "Everything looked clean and really good from the Titan launch."

This will be the first Atlas launch in 2003, ending a four-month lull between flights.

"Even though we launched in December and we do it pretty frequently, for us this has been a while. We have a team that is really eager to launch," said Laffitte.

Riding into space tonight aboard the Atlas 3B rocket -- tail number AC-205 -- is the AsiaSat 4 communications spacecraft. Manufactured by Boeing, the model 601HP satellite carries 28 C-band and 20 Ku-band transponders with a 15-year design life.

Asia Satellite Telecommunications Company of Hong Kong will use the craft from its operational location in geostationary orbit 22,300 miles above the equator at 122 degrees East longitude.

AsiaSat 4 was made to relay telecommunications and broadband multimedia services across the Asia-Pacific region and direct-to-home broadcast services to Hong Kong and the South China area.

A full countdown preview will be posted here following a morning news conference.

And be sure to watch this page for comprehensive play-by-play countdown status reports and updates throughout the flight of Atlas 3.