BY JUSTIN RAY

Follow the countdown and launch of the ULA Atlas 5 rocket carrying a classified payload for the National Reconnaissance Office. Reload this page for the latest on the launch.

THURSDAY, JUNE 14, 2007

The updated launch weather forecast for Friday and Saturday is available here.

And a new collection of pictures showing the Atlas 5 rocket on the launch pad last evening following rollout has been posted here.

1605 GMT (12:05 p.m. EDT)

Tomorrow's launch time will be 11:04 a.m. EDT. The weather outlook calls for a 70 percent chance of acceptable conditions.

Today's trouble involved ratty communications with the ground-based Command Message Encoder Verifier that is part of the Range Safety equipment, an Air Force spokesman says.

Video of today's scrub call is posted here.

1544 GMT (11:44 a.m. EDT)

"This is mission director, mission is scrubbed for the day. We do not have Range clear to launch," was the word to the launch team at 11:39 a.m.

In response, the ULA launch director instructed the team to recycle the countdown for another try on Friday morning.

1541 GMT (11:41 a.m. EDT)

Another launch attempt could be made tomorrow.

1539 GMT (11:39 a.m. EDT)

SCRUB! Range just declared "no go," so the mission director has called a scrub for today.

1538 GMT (11:38 a.m. EDT)

The launch conductor in the Atlas Spaceflight Operations Center four miles from the pad has polled the various console operators to ensure all systems are ready to proceed with the countdown. All elements were "go" pending completion of a Range Safety test.

1536 GMT (11:36 a.m. EDT)

Range is "go" for launch!

1534 GMT (11:34 a.m. EDT)

Now 10 minutes from the rescheduled launch time, pending good news from the Range.

1525 GMT (11:25 a.m. EDT)

While this extended wait continues, Spaceflight Now Plus subscribers are invited to check out a collection of dazzling onboard camera movies from last week's shuttle launch. Both of Atlantis' twin solid rocket boosters were equipped with cameras, giving beautiful views of the launch, booster separation from the shuttle and the fall into the Atlantic for retrieval. See all of the footage here.

1524 GMT (11:24 a.m. EDT)

The countdown remains holding at T-minus 4 minutes. If the Range is able to fix its technical problem, clocks would resume ticking at 11:40 a.m. for a liftoff at 11:44 a.m. There are no issues with the rocket, launch pad or weather.

1517 GMT (11:17 a.m. EDT)

A ULA spokesman says the Range "no go" condition appears to be related to the earlier trouble.

1516 GMT (11:16 a.m. EDT)

The Range is reporting a "no go" at this time due to a technical problem.

1514 GMT (11:14 a.m. EDT)

NEW LAUNCH TIME. Liftoff time is being re-targeted 11:44 a.m. EDT. No word yet on why the slip.

1512 GMT (11:12 a.m. EDT)

Final readiness polls to confirm all elements are "go" for launch will be coming up in a couple of minutes.

1509 GMT (11:09 a.m. EDT)

NEW LAUNCH TIME. Liftoff time is being re-targeted 11:22 a.m. EDT.

1507 GMT (11:07 a.m. EDT)

Range is "go" for launch. The earlier troubles have been resolved.

1504 GMT (11:04 a.m. EDT)

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.

1503 GMT (11:03 a.m. EDT)

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

1502 GMT (11:02 a.m. EDT)

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

1501 GMT (11:01 a.m. EDT)

The latest update from the launch weather officer is quite positive. All conditions are "go" for launch right now. The odds of acceptable conditions for today have increased to 80 percent.

1459 GMT (10:59 a.m. EDT)

The Range command and control issue is expected to be resolved by 11:10 a.m., officials say.

1458 GMT (10:58 a.m. EDT)

Twenty minutes to go, pending Range resolution of its technical issue this morning.

1457 GMT (10:57 a.m. EDT)

The latest guidance and steering data have been loaded into the rocket's flight computer based on today's upper level wind conditions.

1453 GMT (10:53 a.m. EDT)

Flight control final preps are complete.

1452 GMT (10:52 a.m. EDT)

The fuel-fill sequence is starting for the Russian-designed RD-180 main engine.

1445 GMT (10:45 a.m. EDT)

The countdown is ticking along quietly. Awaiting further word on the Range issue that the Air Force reported earlier in the hour.

1438 GMT (10:38 a.m. EDT)

T-minus 30 minutes and counting. The countdown clocks are heading to the T-minus 4 minute mark where a planned 10-minute hold will occur. Liftoff of Atlas 5 on the NROL-30 mission remains scheduled for 11:18 a.m. EDT.

1430 GMT (10:30 a.m. EDT)

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

1426 GMT (10:26 a.m. EDT)

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

1424 GMT (10:24 a.m. EDT)

The first stage liquid oxygen tank is over 80 percent full.

1420 GMT (10:20 a.m. EDT)

Sixty percent of the Centaur liquid hydrogen tank has been filled so far.

1418 GMT (10:18 a.m. EDT)

Launch is now just 60 minutes away. Weather is still looking good at the moment, but the Range is working a technical problem that needs to be resolved before the launch.

1417 GMT (10:17 a.m. EDT)

The first stage liquid oxygen tank is now 70 percent full.

1415 GMT (10:15 a.m. EDT)

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

1413 GMT (10:13 a.m. EDT)

The flight control final preparations are starting.

1409 GMT (10:09 a.m. EDT)

The Range reports one of its mandatory sites required to support the launch has gone down. Efforts are underway to resolve the issue, with hopes of the station being back online by 11 a.m.

1408 GMT (10:08 a.m. EDT)

The Centaur engine chilldown is being initiated.

1408 GMT (10:08 a.m. EDT)

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

1407 GMT (10:07 a.m. EDT)

First stage liquid oxygen tank is now half full. Chilled to Minus-298 degrees F, the liquid oxygen will be used with RP-1 kerosene by the RD-180 main engine on the first stage during the initial four minutes of flight today. The 25,000 gallons of RP-1 were loaded into the rocket prior today's countdown.

1402 GMT (10:02 a.m. EDT)

The first stage liquid oxygen tank is about one-third full.

1356 GMT (9:56 a.m. EDT)

The Centaur liquid oyxgen tank has reached flight level.

1352 GMT (9:52 a.m. EDT)

Ten percent of the first stage liquid oxygen tank has been filled so far.

1349 GMT (9:49 a.m. EDT)

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

And the Centaur liquid oxygen tank has reached the 95 percent level. The topping off process is starting.

1348 GMT (9:48 a.m. EDT)

Now 90 minutes to launch. Countdown activities remain on schedule for liftoff at 11:18 a.m.

1345 GMT (9:45 a.m. EDT)

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

1344 GMT (9:44 a.m. EDT)

The Centaur liquid oxygen tank is nearing three-quarters full.

1339 GMT (9:39 a.m. EDT)

Fifty percent of the Centaur liquid oxygen tank has been filled so far.

1337 GMT (9:37 a.m. EDT)

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.

1332 GMT (9:32 a.m. EDT)

The Centaur liquid oxygen tank is now 20 percent full.

1324 GMT (9:24 a.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 NRO payload into the desired orbit.

1315 GMT (9:15 a.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.

1309 GMT (9:09 a.m. EDT)

Chilldown thermal conditioning of the mobile launch platform upon which the rocket stands is beginning. This is meant to ease the shock on equipment when supercold cryogenic propellants start flowing into the rocket a short time from now.

1308 GMT (9:08 a.m. EDT)

T-minus 120 minutes and counting! Countdown clocks are running again for launch of the Atlas 5 rocket on the NROL-30 mission for the U.S. National Reconnaissance Office. 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 11:18 a.m. EDT from Cape Canaveral's Complex 41.

1303 GMT (9:03 a.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 gave his "go" as well.

1301 GMT (9:01 a.m. EDT)

The ULA launch conductor is briefing his Atlas team on countdown procedures before entering into the final two hours. Launch team readiness polls for proceeding with the count are coming up momentarily.

1255 GMT (8:55 a.m. EDT)

Weather forecasters continue to predict a 70 percent chance of acceptable conditions for today's launch opportunity. Isolated coastal showers and thunderstorms developing later in the morning are the primary concerns.

The launch time outlook calls for scattered clouds at 2,500 and 25,000 feet, good visibility, easterly winds of 12 gusting to 16 knots, a temperature of 78-79 degrees F and the possibility of showers in the area.

Should the launch be delayed to Friday for some reason, the weather is expected to be nearly the same. The only difference is slightly windier conditions, but still a 70 percent chance of "go" weather.

1245 GMT (8:45 a.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.

1238 GMT (8:38 a.m. EDT)

T-minus 2 hours and holding. The countdown has just entered the first of two planned holds over the course of the morning that will lead to the 11:18 a.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.

1232 GMT (8:32 a.m. EDT)

The final members of the launch pad crew are preparing to leave Complex 41.

1218 GMT (8:18 a.m. EDT)

Now three hours from launch. A C-band test with the Range was recently completed. This system allows the Air Force-controlled Eastern Range to track the Atlas 5 rocket during launch. Coming up shortly, Range Safety will perform the hold-fire checks. That will ensures safety officers have the capability of halting the countdown if a problem occurs.

1200 GMT (8:00 a.m. EDT)

It is a beautiful morning along Florida's Space Coast where the United Launch Alliance team is readying an Atlas 5 rocket to haul a secret national security payload into orbit for the U.S. government.

Over the past couple of hours, the launch team completed a flight control operational test, preps of the liquid oxygen and liquid hydrogen systems for the Centaur upper stage, internal battery checks, first stage propulsion and hydraulic preps, configuring of the pad's water deluge system and thermal chilldown of the cryogenic fuel storage areas at the complex.

At this point, all appears to be proceeding smoothly and on schedule for a liftoff at 11:18 a.m. EDT this morning.

1000 GMT (6:00 a.m. EDT)

Clocks are ticking at Cape Canaveral for this morning's launch of the Atlas 5 rocket. The seven-hour countdown process began at 4:18 a.m. EDT as planned. The rocket was powered up, liquid oxygen and liquid hydrogen system preps started, as well as the clearing of workers from the assembly building area near the pad.

WEDNESDAY, JUNE 13, 2007
2115 GMT (5:15 p.m. EDT)

A collection of images from today's rollout to the launch pad can be seen here.

1630 GMT (12:30 p.m. EDT)

Atlas has arrived at the launch pad for Thursday's planned liftoff to deliver into orbit a clandestine satellite cargo for the U.S. National Reconnaissance Office.

Making its 10th trip to space, the United Launch Alliance rocket is targeting an 11:18 a.m. EDT (1518 GMT) blastoff from Complex 41 at Cape Canaveral.

Details about the ascent, including a timeline of the launch events and the intended ground track, aren't being revealed for this mission.

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The launch countdown will begin well before dawn Thursday as ground crews power up the rocket, run through standard pre-flight tests and prepare for fueling the vehicle. Steps to load cryogenic liquid oxygen and liquid hydrogen into the rocket should start shortly after 9 a.m.

This will be the first time the next-generation Atlas 5 has carried a payload for the NRO, which is the secretive government agency responsible for the nation's fleet of spy satellites.

"The NRO develops and operates unique and innovative overhead reconnaissance systems and conducts intelligence-related activities essential for U.S. national security," the pre-launch press release said.

"This launch directly supports NRO's goals of being the foundation for global situational awareness and for providing intelligence information on timelines responsive to user needs."

The trade magazine Aviation Week and Space Technology reported in April that the Atlas would deploy a pair of ocean surveillance satellites.

1615 GMT (12:15 p.m. EDT)

Once in position at the pad, the mobile platform will be locked down, the transporter carriages pulled away and propellant lines hooked up.

1607 GMT (12:07 p.m. EDT)

ROLLOUT UNDERWAY. The Atlas 5 rocket has begun its third-of-a-mile trek from the assembly building to the launch pad.

1545 GMT (11:45 a.m. EDT)

The latest launch weather forecast is posted here.

1305 GMT (9:05 a.m. EDT)

The United Launch Alliance Atlas 5 rocket will travel from the 30-story Vertical Integration Facility to the pad at Cape Canaveral's Complex 41 starting around 12 noon today.

A pair of specially-made "trackmobiles" will push the rocket's 1.4-million pound mobile launching platform along rail tracks for the trip.

The two-stage rocket was assembled inside the VIF in preparation for the mission. Payloads are mounted atop the Atlas in the VIF as well.

The mobile launching platform is what the Atlas 5 sits upon from the time it is stacked in the VIF until the main engine is fired at liftoff. Umbilicals feeding fuel, power and all other lines from the ground to the rocket run through the platform.

The platform is 45 feet wide, 55 feet long and 185 feet tall to the top of the mast, which features a wind damper that holds the rocket steady while exposed to the weather on the pad and routes propellant lines to the Centaur and conditioned air to the payload inside the nose cone.

Two "trackmobiles" transport the rocket the 1,800 feet to the launch pad. Mobile vans are attached to the platform, providing ground communications and equipment for the rocket, command and control and the air purge to the payload.

The rollout typically takes about a half-hour, reaching a top speed about two miles per hour.

Launch remains scheduled for 11:18 a.m. EDT (1518 GMT) on Thursday. The latest weather forecast issued by the Air Force continues to predict a 70 percent chance of good conditions.

TUESDAY, JUNE 12, 2007
1525 GMT (11:35 a.m. EDT)

The Air Force this morning announced the target launch time for the Atlas 5 rocket. Liftoff on Thursday is scheduled for 11:18 a.m. EDT (1518 GMT).

The duration of the day's launch window hasn't been disclosed. However, officials previously said the launch would not happen after 12 noon.

Weather forecasters have improved the odds of acceptable conditions for Thursday morning. The outlook now predicts a 70 percent chance of meeting the launch weather rules. See the full forecast here.

MONDAY, JUNE 11, 2007

A United Launch Alliance Atlas 5 rocket is scheduled to launch a classified payload for the U.S. National Reconnaissance Office on Thursday morning from Cape Canaveral.

The rocket will fly in the 401 vehicle configuration with a four-meter fairing, no solid rocket boosters and a single-engine Centaur upper stage.

Although the exact launch time has not been revealed, the Air Force says liftoff will happen sometime betwen 9 a.m. and noon EDT (1300-1600 GMT).

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

The weather forecast predicts a 60 percent chance of acceptable conditions on launch day. Thick clouds and disturbed weather associated with isolated showers in the area are the main concerns. See the full forecast here.