BY JUSTIN RAY

Follow the countdown and launch of the ULA Atlas 5 rocket carrying the U.S. military's first Wideband Global SATCOM spacecraft. Reload this page for the latest on the launch.

Additional coverage for subscribers:
VIDEO: PRE-LAUNCH NEWS CONFERENCE PLAY
SUBSCRIBE NOW

THURSDAY, OCTOBER 12, 2007

An advanced communications satellite with as much capacity as the entire orbiting fleet of craft that it will help replace was successfully shot into orbit Wednesday night atop a 19-story Atlas 5 rocket.

As the sun set over Florida's Cape Canaveral launch base, the rocket was fueled with supercold propellants for a liftoff at 8:22 p.m. EDT. The countdown rolled along smoothly and the million-pound rocket made its thunderous departure from Complex 41 right on schedule.

Read our launch story.

0130 GMT (9:30 p.m. EDT Wed.)

"As America celebrates the 60th anniversary of the Air Force, today's launch of the WGS satellite is a fitting tribute," said Jim Sponnick, ULA vice president of Atlas programs. "ULA is proud of its continuing role of providing reliable and cost effective assured access to space for the Air Force's critical missions."

0120 GMT (9:20 p.m. EDT Wed.)

Tonight's launch has been a complete success, United Launch Alliance has announced. And ground controllers have acquired the first signals from the WGS satellite.

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

Our time-lapse streak photos of tonight's launch are posted here.

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

T+plus 31 minutes, 40 seconds. SPACECRAFT SEPARATION! The Centaur upper stage has deployed the first Wideband Global SATCOM communications spacecraft for the U.S. Air Force, completing tonight's launch.

Built by Boeing with a price tag of $350 million, the sophisticated satellite promises to provide a major increase in communications capacity for the Defense Department. It is the first of five such WGS spacecraft being constructed for launches over the next five years that will upgrade the military's orbiting communications satellite infrastructure.

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

T+plus 29 minutes, 30 seconds. Centaur is maneuvering itself to the proper orientation for releasing WGS.

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

T+plus 28 minutes, 50 seconds. MECO 2. Main engine cutoff confirmed. Centaur has completed its second burn of the night. Release of the payload from the rocket is expected in about three minutes.

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

T+plus 26 minutes, 25 seconds. Engine continues to burn well.

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

T+plus 25 minutes, 45 seconds. The vehicle is nearly 6,000 miles downrange.

0046 GMT (8:46 p.m. EDT Wed.)

T+plus 24 minutes, 35 seconds. Good chamber pressure and pump speeds on the RL10.

0046 GMT (8:46 p.m. EDT Wed.)

T+plus 24 minutes, 14 seconds. Ignition! The Centaur's single Pratt & Whitney Rocketdyne RL10 engine has re-ignited to accelerate the WGS payload into a supersynchronous transfer orbit.

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

T+plus 23 minutes, 15 seconds. About one minute from engine start. Tank pressurization has started in preparation for ignition.

0044 GMT (8:44 p.m. EDT Wed.)

T+plus 22 minutes. Centaur is 138 miles in altitude, some 4,800 miles downrange from the Cape.

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

T+plus 20 minutes. All indications say this has been a smooth ascent tonight. Centaur systems are reported normal during this coast period.

0039 GMT (8:39 p.m. EDT Wed.)

T+plus 17 minutes. A map of the rocket's planned ground track for tonight's launch is available here.

0037 GMT (8:37 p.m. EDT Wed.)

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

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

T+plus 13 minutes, 20 seconds. Two minutes to go in this first of two firings by the Centaur tonight.

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

T+plus 11 minutes, 20 seconds. Centaur performance is still looking good. The RL10 engine is burning liquid hydrogen and liquid oxygen propellants.

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

T+plus 10 minutes, 30 seconds. About five minutes remaining in this firing of Centaur to reach a parking orbit around Earth.

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

T+plus 9 minutes, 20 seconds. The rocket 122 miles in altitude and over 1,300 miles downrange from the launch pad as the vehicle flies eastward.

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

T+plus 8 minutes, 30 seconds. The RL10 engine continues to burn normally.

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

T+plus 7 minutes, 45 seconds. The rocket 100 miles in altitude, more than 900 miles downrange and traveling at 13,575 mph.

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

T+plus 6 minutes, 50 seconds. Centaur is rolling to get better alignment with NASA's Tracking and Data Relay Satellite.

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

T+plus 5 minutes, 25 seconds. Centaur systems and engine chamber pressure readings all look good.

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

T+plus 4 minutes, 43 seconds. The two-halves of the Atlas 5 rocket nose cone encapsulating the WGS spacecraft have separated.

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

T+plus 4 minutes, 34 seconds. Ignition of Centaur! The RL10 powerplant is up and running at full thrust.

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

T+plus 4 minutes, 24 seconds. The RD-180 main engine has completed its burn and shut down. And the Atlas 5's Common Core Booster first stage has been jettisoned!

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

T+plus 4 minutes. The engine is throttling down to keep a constant 5'g acceleration.

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

T+plus 3 minutes. It has been a thunderous departure for the Atlas and WGS tonight! The RD-180 main engine continues to fire normally, burning its mixture of highly refined kerosene and liquid oxygen.

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

T+plus 2 minutes, 22 seconds. The Aerojet-made solid rocket boosters have separated from the Atlas 5, having completed their job of adding a kick at liftoff.

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

T+plus 105 seconds. Atlas is 13.5 miles in altitude and 13.8 miles downrange.

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

T+plus 93 seconds. Solid rocket booster burnout has occurred. But the spent motors will remain attached to the first stage for about 50 seconds, until the Atlas 5 reaches a point where the airborne dynamic pressure reduces to an allowable level for a safe jettison.

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

T+plus 60 seconds. One minute since liftoff. Vehicle has passed Mach 1.

0022 GMT (8:22 p.m. EDT Wed.)

T+plus 30 seconds. The RD-180 main engine and both solid rocket boosters are burning to power the Atlas 5 into the clear evening sky.

0022 GMT (8:22 p.m. EDT Wed.)

T+plus 7 seconds. And the vehicle has cleared the tower!

0022 GMT (8:22 p.m. EDT Wed.)

LIFTOFF! Liftoff of the Atlas 5 rocket on a dedicated military mission, launching the Defense Department's highest capacity communications satellite!

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

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

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

T-minus 1 minute. Now 60 seconds from liftoff of the Wideband Global SATCOM communications spacecraft.

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

T-minus 90 seconds. Launch control system is enabled. The flight termination system has been armed.

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

T-minus 1 minute, 50 seconds. The automatic computer sequencer is in control of all the critical events through liftoff.

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

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 about 10 seconds.

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

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.

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

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

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

T-minus 4 minutes and counting. The final phase of tonight's countdown has begun for the launch of the ULA Atlas 5 rocket on the WGS deploy mission! Liftoff is targeted to occur at 8:22 p.m.

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

Picking up the count in one minute.

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

Countdown clocks will resume in two minutes. We are now six minutes from launch.

0015 GMT (8:15 p.m. EDT Wed.)

The ULA launch director and the government mission director each have given their approval to press onward with the countdown.

0015 GMT (8:15 p.m. EDT Wed.)

No problems were reported by the launch team during the just-completed poll. All systems are in readiness to continue with the countdown for an on-time liftoff at 8:22 p.m.

0015 GMT (8:15 p.m. EDT Wed.)

Launch team polling is underway.

0010 GMT (8:10 p.m. EDT Wed.)

Coming up in five minutes at 8:15 p.m. EDT, the launch team will be polled for a "go" or "no go" to proceed with the count.

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

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

0007 GMT (8:07 p.m. EDT Wed.)

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

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

The first stage liquid oxygen tank is reported at flight level.

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

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

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

The technical issue has been cleared. It is not a constraint to launch.

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

An update from the launch weather officer indicates all conditions are acceptable for a liftoff tonight.

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

Launch is scheduled for 20 minutes from now. The launch team is discussing one technical issue associated with a bolt-cutter.

2357 GMT (7:57 p.m. EDT)

Flight control final preps are complete.

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

Thirty minutes to go. Tonight's launch will be the 11th for an Atlas 5 rocket since debuting in August 2002. The vehicle's flights have featured a very diverse payload list, including NASA space probes to Mars and Pluto, experimental U.S. military spacecraft, a pair of spy satellites and several commercial communications craft.

This flight is the first to use the rocket's 421 configuration. The Common Core Booster first stage is outfitted with the RD-180 main engine, two solid rocket boosters are attached for added thrust at liftoff, the Centaur upper stage has a single RL10 cryogenic engine and the payload shroud is the four-meter diameter option.

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

The Centaur liquid hydrogen tank has reached flight level.

2342 GMT (7:42 p.m. EDT)

Forty minutes from liftoff. The countdown clocks are heading to the T-minus 4 minute mark where a planned 10-minute hold will occur. Launch of Atlas 5 on the WGS satellite deployment mission remains scheduled for 8:22 p.m. EDT.

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

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

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

Range Safety is conducting the standard pre-launch check of the flight termination system.

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

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

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

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

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

Launch is now just 60 minutes away. At liftoff tonight, the Atlas 5 rocket will weigh 956,448 pounds. The Wideband Global SATCOM spacecraft payload accounts for 12,796 pounds of that weight.

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

The first stage liquid oxygen tank is about three-quarters full.

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

The Centaur liquid hydrogen tank is 50 percent full. The cryogenic propellant will be consumed with liquid oxygen by the stage's Pratt & Whitney-made RL10 engine.

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

The Centaur liquid oyxgen tank has reached flight level.

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

The Centaur engine chilldown has been initiated.

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

Centaur LH2 loading. Chilldown of the liquid hydrogen system is now complete, allowing the super-cold fuel to begin filling the Centaur upper stage.

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

First stage liquid oxygen tank is 40 percent 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 minutes of flight today. The 25,000 gallons of RP-1 were loaded into the rocket prior today's countdown.

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

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

2252 GMT (6:52 p.m. EDT)

Now 90 minutes from the scheduled launch time. The sun is beginning to set on a beautiful Florida evening. The weather is perfect for a spectacular launch.

There had been an issue with the Eastern Range under discussion. However, officials now say the problem has been resolved and it is no longer a constraint to launch.

Activities remain on schedule for a liftoff at 8:22 p.m.

2250 GMT (6:50 p.m. EDT)

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

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

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

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

About three-quarters of the Centaur liquid oxygen tank has been filled so far.

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

Atlas LOX loading.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. It holds about 50,000 gallons of cryogenic oxidizer for the RD-180 main engine.

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

The Centaur liquid oxygen tank is 30 percent full.

2228 GMT (6:28 p.m. EDT)

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

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

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

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

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

T-minus 120 minutes and counting! The launch countdown is continuing for this evening's flight of the Atlas 5 rocket to deploy the Wideband Global SATCOM communications satellite for the U.S. Air Force.

Clocks have one more built-in hold planned at T-minus 4 minutes. That pause will last 10 minutes during which time the final "go" for launch will be given. All remains targeted for liftoff at 8:22 p.m. EDT from Cape Canaveral's Complex 41.

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

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

All console operators in the Atlas Spaceflight Operations Center reported a "ready" status during the pre-fueling poll just completed by the launch conductor. The launch director and mission director gave their approvals as well.

Just prior to the poll, the ULA launch conductor briefed his team on countdown procedures before entering into the final two hours.

2146 GMT (5:46 p.m. EDT)

Safety officials report the blast danger area surrounding the pad has been cleared of all personnel. The remainder of the countdown is considered hazardous, prompting the necessary protection around the launch complex.

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

T-minus 2 hours and holding. The countdown has just entered the first of two planned holds over the course of the evening that will lead to the 8:22 p.m. EDT launch of Atlas. This initial pause lasts 30 minutes, giving the some margin in the countdown timeline to deal with technical issues or any work that is running behind. The final hold is scheduled to occur at T-minus 4 minutes and last for 10 minutes.

2137 GMT (5:37 p.m. EDT)

The final members of the launch pad crew have finished their work and are leaving Complex 41 now.

2135 GMT (5:35 p.m. EDT)

The launch weather officer just offered a briefing to mission managers. The outlook for tonight is quite favorable, with just some scattered clouds, unrestricted visibility, a temperature around 80 degrees F and an east-southeast wind of 10 gusting to 15 knots.

2127 GMT (5:27 p.m. EDT)

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

A little earlier in the count, a C-band test with the Range was completed. This system allows the Air Force-controlled Eastern Range to track the Atlas 5 rocket during launch.

2122 GMT (5:22 p.m. EDT)

Three hours and counting down to launch time. Readying of this Atlas 5 rocket at Cape Canaveral started on April 23 when hardware began arriving here, said Lt. Col. Steve Steiner, the 5th Space Launch Squadron commander.

The rocket was rolled to the Complex 41 pad for a countdown dress rehearsal September 8, which included fueling of the stages with propellant and conducting a full launch day simulation.

The WGS satellite was mounted atop the rocket on September 27, beginning the final phase of the launch campaign. The 19-story vehicle was wheeled back to the pad from the assembly building yesterday morning to start the countdown sequence.

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

Guidance system testing and the flight control countdown preps are complete.

2048 GMT (4:48 p.m. EDT)

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

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

First stage propulsion and hydraulic preps, along with liquid oxygen system preps have been completed. And crews report they have finished removing access platforms and handrails on the mobile launch platform and around the pad area.

2022 GMT (4:22 p.m. EDT)

Now four from liftoff time. Internal battery checks were just accomplished.

Tonight's launch will put the first Wideband Global SATCOM communications satellite into orbit for the U.S. military and mark resumption of flights for the Atlas 5 rocket after a valve problem interfered with the vehicle's last ascent in June.

"This is an extremely important mission for a lot of reasons -- certainly our combat warriors depend on the satellite we're going to be launching, but also for the Atlas program. We're very excited to be back into operations following an anomaly on our previous mission. We resolved that conclusively and comprehensively," said Col. Michael Moran, the Atlas group commander.

A detailed story on the valve problem and the remedy for this launch is available here.

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

Final preps of the liquid oxygen and liquid hydrogen systems for the Centaur upper stage are reported complete. The early portion of today's countdown is progressing quietly under sunny skies.

A photo taken by Spaceflight Now's Justin Ray at the launch pad this afternoon is posted here. More images will be posted later.

1922 GMT (3:22 p.m. EDT)

Launch of the Atlas 5 rocket is just five hours away now. The countdown began as scheduled this afternoon and officials are not reporting any significant problems. The weather continues to look favorable. We'll begin our live play-by-play mission updates shortly.

1230 GMT (8:30 a.m. EDT)

Check out some additional photos of the rocket's move to the launch pad here.

TUESDAY, OCTOBER 9, 2007

Countdown clocks will begin ticking at 1:22 p.m. EDT Wednesday afternoon as the United Launch Alliance Atlas 5 rocket team and the U.S. Air Force prepare for an evening liftoff from Cape Canaveral, Florida.

Launch from Complex 41 is slated to occur at 8:22 p.m. EDT, beginning a half-hour flight to supersynchronous transfer orbit to deploy the Wideband Global SATCOM communications spacecraft.

Built by Boeing with a price tag of $350 million, the sophisticated satellite promises to provide a major increase in communications capacity for the Defense Department. It is the first of five such WGS spacecraft being constructed for launches over the next five years that will upgrade the military's orbiting communications satellite infrastructure.

"WGS Space Vehicle 1 will be MILSATCOM's first launch of a new satellite family in 13 years," said Col. David Uhrich, the Military Satellite Communications Systems Wing vice commander at the Air Force's Space and Missile Systems Center in Los Angeles.

"Tomorrow's launch begins the process of augmenting and eventually replacing the Defense Satellite Communications System (DSCS), which has been the Department of Defense's backbone for satellite communications for the last two decades."

A single WGS satellite has as much communications capacity as the entire 9-satellite DSCS constellation flying today, Col. Uhrich indicated.

The Atlas 5 rocket was rolled from its assembly building to the launch pad Wednesday morning, and officials told reporters during an afternoon news conference that preparations were proceeding smoothly.

"We are working no issues, the vehicle is green for launch and the entire government and United Launch Alliance team is trained and ready to support to give the WGS satellite a very sweet ride into its proper orbit," said Lt. Col. Steve Steiner, 5th Space Launch Squadron commander at Cape Canaveral.

"The vehicle and payload system teams have worked hand in hand to bring us to this point where we are just a day away from launch," added Jim Sponnick, ULA's vice president for Atlas programs. "We anticipate our Atlas 5 vehicle is going to perform exceptionally well, allowing WGS to perform the enhanced communications capabilities and provide those to our troops in the field."

The weather outlook for Wednesday evening's 71-minute launch window, which runs from 8:22 to 9:33 p.m. EDT (0022-0133 GMT), calls for some scattered clouds, a northeast breeze and a temperature in the high 70s F. There is a chance for an isolated rain shower, but meteorologists put the odds of acceptable liftoff weather at 80 percent.

"Weather is looking very favorable for launch," said Capt. Christopher Lovett, the launch weather officer. "Weather should cooperate quite nicely."

Once the countdown clocks begin ticking in the early afternoon, the launch team will power up the rocket and begin standard pre-flight tests. Crews at the pad will make preparations to systems and equipment before the site is cleared of all personnel around 5:30 p.m.

A planned half-hour hold begins at 5:42 p.m. when the count reaches T-minus 120 minutes. Near the end of the hold, the team will be polled at 6:07 p.m. to verify all is in readiness to start fueling the rocket for launch.

Supercold liquid oxygen begins flowing into the Centaur upper stage around 6:30 p.m., followed by the first stage filling a little before 6:45 p.m. Liquid hydrogen fuel loading for Centaur will be completed a short time later.

A final hold is scheduled at the T-minus 4 minute mark starting at 8:08 p.m. That will give everyone a chance to finish any late work and assess the status of the rocket, payload, Range and weather before proceeding into the last moments of the countdown.

The RD-180 main engine and twin strap-on solid rocket boosters will power the 19-story rocket off the launch pad for an eastward arc across the Atlantic Ocean.

The Centaur upper stage will perform a pair of firings, eventually reaching an elliptical orbit stretching from 250 nautical miles at its lowest point to upwards of 40,000 nautical miles at its highest. Release of the WGS satellite to complete the launch is expected 31 minutes and 32 seconds after liftoff.

Ground controllers will maneuver the satellite into a circular geostationary orbit and fully check out the communications gear before it enters service to cover southeast Asia and the Pacific Ocean region.

"WGS will provide a quantum leap in communications coverage, capacity and connectivity for our Marines, Soldiers, Sailors and Airmen, and will become the Department of Defense's highest capacity communications satellite," Col. Uhrich said. "What that means to our warfighters out in the field, they will be able to process, receive and transmit data quicker than ever."

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

A collection of photos showing the Atlas 5 rocket rolling out to the launch pad this morning is posted here.

1435 GMT (10:35 a.m. EDT)

ON THE PAD! The Atlas 5 rocket has arrived at the Complex 41 launch pad for liftoff about 34 hours from now to deliver into orbit the Air Force's highest capacity communications satellite -- the first Wideband Global SATCOM spacecraft.

The two mobile trailers connected to the launching platform, which were part of the convoy during this morning's rollout, soon will be hooked up to power and communications systems at the pad. These trailers provide conditioned air to the payload and communications with the rocket during the rollout and the countdown. They are protected from the blast of launch by a concrete structure on the north-side of the platform.

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

Later this afternoon, the undercarriages used to move the mobile platform will be disconnected and the "trackmobiles" pulled free. Crews will secure the rocket and pad for the night. The launch countdown commences at 1:22 p.m. EDT tomorrow, some seven hours before liftoff time.

There has been some conflicting information given to the press about the launch time. But officials now confirm that tomorrow's launch window is 8:22 to 9:33 p.m. EDT. The window does not open at 8:21 p.m. as had been advertised.

A pre-launch news conference is coming up today. Check this page tonight for a countdown and launch preview.

1404 GMT (10:04 a.m. EDT)

ROLLOUT BEGINS! It's time to put the Atlas 5 rocket on the pad for tomorrow night's launch of the Air Force's Wideband Global SATCOM communications spacecraft.

The United Launch Alliance rocket just began a slow half-hour drive from the 30-story Vertical Integration Facility at Cape Canaveral's Complex 41 to the launch pad.

A pair of specially-made "trackmobiles" are pushing the Atlas 5 rocket's 1.4-million pound mobile launching platform along rail tracks for this 1,800-foot trip.

The Atlas was assembled inside the VIF this summer starting with erection of the bronze first stage equipped with the kerosene-fueled RD-180 main engine. The hydrogen-fueled Centaur upper stage was then added. And to give the rocket added thrust at liftoff, two long solid propellant boosters were attached to the first stage. The WGS satellite was prepped offsite and encapsulated in the nose cone shroud, then brought to the VIF for hoisting atop the Atlas.

1215 GMT (8:15 a.m. EDT)

The Vertical Integration Facility this morning, activities are underway to prepare for rollout of the Atlas 5 rocket from that assembly building to the launch pad.

Bolted aboard its mobile launching platform, the rocket will be transported by rail about one-third-of-a-mile to the Complex 41 pad beginning around 10 a.m. EDT (1400 GMT).

Launch remains targeted for Wednesday evening during a 72-minute window extending from 8:21 to 9:33 p.m. EDT (0021-0133 GMT).

The latest weather outlook for launch time includes increased odds of acceptable conditions. There's now an 80 percent chance that weather will be favorable for the liftoff. See the full forecast here.

MONDAY, OCTOBER 8, 2007
1800 GMT (2:00 p.m. EDT)

The updated launch weather forecast for Wednesday evening is posted here.

1210 GMT (8:10 a.m. EDT)

DELAY. Launch of the Atlas 5 rocket has been postponed 24 hours to give engineers and officials time to review a potential technical concern.

Liftoff from Cape Canaveral's Complex 41 is targeted for Wednesday at 8:21 p.m. EDT. The evening's launch window will extend 72 minutes to 9:33 p.m. EDT.

"A review of data from previous Delta 4 missions noted a data signature that differs from other flight experience. The difference has raised a question for Atlas 5 given the Atlas and Delta launch vehicles have some common or similar components," ULA said in a statement.

"The additional time will allow engineers to sufficiently understand the data signature and ensure there are no mission success implications for the Atlas 5/WGS launch."

SUNDAY, OCTOBER 7, 2007

The Atlas rocket program looks to return to its successful ways this week, launching a powerful U.S. military communications satellite Tuesday night with a tried-and-true engine valve instead of a newer design blamed for creating serious problems during the last ascent four months ago.

Read our preview story.

SATURDAY, OCTOBER 6, 2007

The latest launch weather forecast issued this morning is posted here.

FRIDAY, OCTOBER 5, 2007

A United Launch Alliance Atlas 5 rocket is scheduled to launch a U.S. military communications satellite on Tuesday evening from Cape Canaveral.

The rocket will fly in the 421 vehicle configuration with a four-meter fairing, two solid rocket boosters and a single-engine Centaur upper stage.

Liftoff is targeted for 8:22 p.m. EDT at the opening of a 71-minute launch window that extends through 9:33 p.m. EDT (0022-0133 GMT).

The rocket will be rolled from the Vertical Integration Facility to the Complex 41 launch pad atop its mobile platform on Monday morning.

The weather forecast predicts a 70 percent chance of acceptable conditions on launch day. Clouds and disturbed weather associated with isolated showers in the area are the main concerns. See the full forecast here.