BY JUSTIN RAY

Follow the preparations and launch of Boeing's Delta 4 rocket carrying the Air Force's DSCS 3-B6 communications satellite. Reload this page for the very latest on the mission.

Video coverage for subscribers only:
   VIDEO: 5 1/2-MINUTE CLIP OF DELTA 4 ROCKET LAUNCHING QT
   VIDEO: ONBOARD CAMERA VIEW OF THE LIFTOFF QT
   VIDEO: ONBOARD VIEW OF DSCS 3-B6 DEPLOYING QT
   VIDEO: ANOTHER CAMERA VIEW OF SPACECRAFT SEPARATION QT
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FRIDAY, AUGUST 29, 2003

After four decades and two dozen launches, the Air Force's longest-running communications satellite system received its final member Friday with the successful flight of Boeing's Delta 4 rocket. Read our full story.

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

The official Range liftoff time this evening was 7:13:00.22 p.m. EDT.

0001 GMT (8:01 p.m. EDT Fri.)

"Thanks to Boeing for the great ride," a happy Christine Anderson, the Air Force's DSCS program manager, said a few moments ago from the launch control center.

The Delta 4 rocket has achieved success in all three of its missions. The next flight is scheduled for next spring when the Delta 4-Heavy vehicle will take an Air Force-funded test launch.

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

The spacecraft deployment orbit has an apogee of 19,222.7 nautical miles, perigee of 126.95 nautical miles and inclination of 25.49 degrees, well within the targets according to Boeing.

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

T+plus 42 minutes, 7 seconds. SPACECRAFT SEPARATION! The U.S. Air Force's Defense Satellite Communications System 3-B6 spacecraft has been released from the Delta 4 rocket's upper stage.

This completes the 301st Delta rocket launch, the third for Delta 4 and the second flight for the military's Evolved Expendable Launch Vehicle program.

2353 GMT (7:53 p.m. EDT)

T+plus 40 minutes, 20 seconds. About two minutes remain until payload deployment. The second stage remains in a normal coast mode.

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

T+plus 39 minutes, 40 seconds. Spin-up is complete. The spin rate has reached about 26.7 degrees per second as planned, Boeing says.

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

T+plus 38 minutes, 5 seconds. The spin-up maneuver by the second stage has started in preparation for deployment of DSCS. A sequence of six "roll rate" steps is used to spin the vehicle to 4.6 rpm.

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

T+plus 36 minutes. Data from the Delta 4 still looking good as the upper stage coasts through space before deploying the DSCS payload.

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

T+plus 33 minutes, 30 seconds. The vehicle has passed out of range from the Ascension Island tracking station. The Hartebeesthoek station in South Africa has since acquired the rocket's signal.

2345 GMT (7:45 p.m. EDT)

T+plus 32 minutes. The proper geosynchronous transfer orbit has achieved by the Delta 4 rocket, Boeing says. Data shows an apogee of 19,329.7 nautical miles, perigee of 126.1 nautical miles and inclination of 25.49 degrees.

2343 GMT (7:43 p.m. EDT)

T+plus 30 minutes, 45 seconds. The upper stage has entered a normal coast mode. It will be performing a planned maneuver to the spacecraft deployment attitude over the next few minutes. Separation of DSCS from the rocket is expected at T+plus 42 minutes, 2 seconds.

2343 GMT (7:43 p.m. EDT)

T+plus 30 minutes, 17 seconds. SECO 2. The second firing of the upper stage has completed, ending the powered phase of the Delta 4's mission to loft DSCS.

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

T+plus 29 minutes, 10 seconds. Good engine chamber pressure still being reported. About one minute left in this burn by the Delta 4 rocket's upper stage.

2341 GMT (7:41 p.m. EDT)

T+plus 28 minutes, 30 seconds. The Pratt & Whitney RL10 engine still burning normally.

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

T+plus 27 minutes, 30 seconds. The engine firing continues with no problems reported.

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

T+plus 26 minutes, 45 seconds. Engine chamber pressure reported normal.

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

T+plus 26 minutes, 11 seconds. The RL10B-2 liquid hydrogen/liquid oxygen engine has been reignited to finish the job of boosting the DSCS satellite into the intended orbit. This will be a four-minute firing.

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

T+plus 26 minutes, 2 seconds. Hydrogen and oxygen pre-start activities have started.

2337 GMT (7:37 p.m. EDT)

T+plus 24 minutes. Restart of the upper stage is about two minutes away.

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

T+plus 23 minutes. To see the track the rocket is following this evening, click here.

2335 GMT (7:35 p.m. EDT)

T+plus 22 minutes, 10 seconds. A quiet coast mode is reported by the upper stage of Delta 4.

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

T+plus 21 minutes, 30 seconds. Ascension has acquired the rocket's signal. Good, clean data being reported from the Delta 4 rocket.

2333 GMT (7:33 p.m. EDT)

T+plus 20 minutes. By this point in the flight, the upper stage should have maneuvered itself into the proper attitude for engine restart. However, the vehicle is out of range from any ground station and the maneuver can't be confirmed in real-time. Ignition of the RL10 engine is about six minutes away.

2330 GMT (7:30 p.m. EDT)

T+plus 17 minutes. The vehicle has passed out of range from the Antigua tracking station. The next live telemetry will come via tracking station on Ascension Island to cover the final burn of the upper stage. The RL10B-2 engine is due to start at T+plus 26 minutes, 3 seconds.

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

T+plus 16 minutes. The orbit achieved has a high point of 216.7 nautical miles, low point of 100.2 nautical miles and inclination of 29.2 degrees to the equator. All parameters are right on target.

Boeing reports the RL10B-2 engine burned about five seconds longer than planned. However, that is well within acceptable margin.

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

T+plus 14 minutes, 29 seconds. SECO 1. Confirmation that the second stage engine has shut down after the first of two planned firings to inject the DSCS spacecraft into geosynchronous transfer orbit.

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

T+plus 13 minutes, 30 seconds. Guidance data from the vehicle looks normal. Altitude 203 miles, downrange distance 1,700 miles, velocity nearing 15,500 mph.

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

T+plus 12 minutes. Good data still being reported from the Antigua station. Just over two minutes remaining in this firing by the second stage.

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

T+plus 11 minutes, 20 seconds. The vehicle is nearing an altitude of 200 miles. A good flight so far for the Delta 4 rocket, Boeing says.

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

T+plus 9 minutes, 45 seconds. Good chamber pressure data being reported from the RL10 engine as it thrusts to reach orbit.

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

T+plus 8 minutes, 45 seconds. The Antigua tracking station has picked up the rocket's signal.

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

T+plus 7 minutes, 30 seconds. Altitude 160 miles, downrange distance 630 miles, velocity nearing 11,000 mph.

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

T+plus 6 minutes, 15 seconds. The upper stage systems are operating properly as the RL10 engine fires to reach a low-altitude parking orbit this evening.

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

T+plus 5 minutes, 10 seconds. The protective payload fairing enclosing the DSCS satellite atop the rocket has separated.

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

T+plus 4 minutes, 50 seconds. The cryogenic RL10B-2 upper stage engine has ignited! Good thrust reported.

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

T+plus 4 minutes, 40 seconds. The Common Booster Core first stage and the attached interstage have been separated in one piece from the Delta 4's upper stage. The upper stage engine's extendible nozzle is dropping into position.

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

T+plus 4 minutes, 21 seconds. MECO! Main engine cutoff confirmed as the Rocketdyne RS-68 powerplant shuts down.

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

T+plus 3 minutes, 40 seconds. The RS-68 powerplant is throttling down to about 58 percent as planned.

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

T+plus 2 minutes, 30 seconds. The first stage main engine continues to fire normally. Altitude 17 miles, downrange distance 44 miles, velocity nearing 3,100 mph.

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

T+plus 1 minute, 55 seconds. Altitude 7 miles, downrange distance 27 miles, velocity nearing 2,000 mph.

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

T+plus 1 minute, 40 seconds. The vehicle is right on the proper course.

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

T+plus 1 minute, 25 seconds. The Delta 4 rocket has passed Mach 1.

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

T+plus 45 seconds. Good engine steering reported in the light high-altitude winds.

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

T+plus 30 seconds. The Delta 4 rocket has manuevered to the desired eastward heading for the trek to geosynchronous transfer orbit. The main engine is powering the vehicle at full throttle.

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

LIFTOFF! Liftoff of the Boeing Delta 4 rocket launching DSCS 3-B6 -- the final spacecraft for the U.S. military's longest-running communications satellite constellation. And the vehicle has cleared the tower!

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

T-minus 20 seconds. The terminal countdown sequencer will take control at T-minus 8.5 seconds. Ignition of the RS-68 powerplant will follow at T-minus 5.5 seconds. The engine powers up to the 102 percent level of thrust for a computer-controlled checkout before liftoff.

Upper stage liquid hydrogen tank is ready.

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

T-minus 1 minute and counting. The Eastern Range has given its "go" for launch. And the ignition parameters for the RS-68 main engine are met.

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

T-minus 2 minutes and counting. First stage liquid hydrogen tank is at flight level and pressure. The first and second stage liquid oxygen tanks are now being secured.

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

T-minus 3 minutes and counting. The first stage propellant is being secured. And pressurization of the tank has started.

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

T-minus 4 minutes and counting. Vehicle ordnance is being armed.

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

T-minus 4 minutes, 30 seconds. The systems of the first and second stages of the Delta 4 rocket have switched from ground-fed power to internal batteries for launch.

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

T-minus 5 minutes and counting! The final phase of today's countdown has commenced for launch of Boeing's Delta 4 rocket carrying the Defense Satellite Communications System 3-B6 spacecraft. Liftoff is set to occur at 7:13 p.m. EDT (2313 GMT) from pad 37B at Cape Canaveral Air Force Station.

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

The countdown will resume in one minute. Launch of the Delta 4 rocket is just six minutes away from Cape Canaveral.

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

The Boeing launch team and weather officer have been polled for a "go" to resume the countdown. No problems were reported! Liftoff is now 9 minutes away.

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

Launch Weather Officer Joel Tumbiolo reports that thuderstorm has dissipated. All weather rules will be "go" at the opening of tonight's window.

2258 GMT (6:58 p.m. EDT)

The payload team reports the DSCS spacecraft atop the Delta 4 has been configured for launch. This is the 65th and last satellite in the DSCS family to fly since 1966.

Today, the Pentagon operates a constellation of DSCS satellites for super high frequency, anti-jam communications around the planet. The system supports troops on the ground, aircraft in the sky, ships at sea, the White House Communications Agency and the State Department.

The system is considered the "backbone" for the U.S. government's global communications network.

2258 GMT (6:58 p.m. EDT)

Now 15 minutes from launch time. The launch team says there are no technical problems being tracked, the weather team is becoming optimistic that the thunderstorm offshore won't be a constraint and upper level winds are verified acceptable.

2253 GMT (6:53 p.m. EDT)

T-minus 5 minutes and holding. The countdown has entered a planned 15-minute hold. This pause is designed to give the launch team the opportunity to catch up on any work that could be running behind schedule and verify all is in readiness for the final moments of the count. A series of management polls will be conducted during the hold to give approval to proceed with the launch. Liftoff remains scheduled for 7:13 p.m. EDT.

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

The launch pad swing arm retraction system pins are being pulled. The three arms will be rotated away from the Delta 4 rocket at liftoff.

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

T-minus 10 minutes and counting. The countdown will enter a planned hold in five minutes. Launch is still targeted for 7:13 p.m. EDT (2313 GMT), pending weather and final readiness checks with the launch team.

2240 GMT (6:40 p.m. EDT)

The Range tests have been completed without any trouble reported.

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

Launch Weather Officer Joel Tumbiolo just briefed officials:

"There is one (thunderstorm) cell that is 28 nautical miles to our east. We have the weather aircraft going out there. If it were to hold together, it would not necessarily pass right over the pad but...it could cause a cumulus avoidance violation," he reported.

"If it gets within 10 nautical miles and the cloud top is above 26,600 feet, it would be a violation to the cumulus cloud rule."

The top is believed to be around 35,000 feet.

Projections show the cell would be about 6 miles from the pad at launch time. But it is moving quickly and there hasn't been any lightning associated with the storm.

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

The Air Force-controlled Eastern Range is now running inhibited command destruct receiver checks. This ensures safety personnel can destroy the Delta 4 rocket if it veers off course or experiences a problem during launch.

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

T-minus 30 minutes and counting. Clocks are ticking to the T-minus 5 minute mark where a 15-minute hold is planned. Launch is still slated for 7:13 p.m. EDT.

The Range Safety checks are upcoming momentarily.

2218 GMT (6:18 p.m. EDT)

The RS-68 first stage main engine spin start pressurization operation is now underway.

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

The thermal insulation checks have been conducted successfully. Meanwhile, a check of the weather shows that all launch rules are currently "go" for the mission.

2213 GMT (6:13 p.m. EDT)

Now an hour away from the opening of today's launch window. That window extends for 78 minutes from 7:13 to 8:31 p.m. EDT.

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

The first stage Common Booster Core main engine and the roll control nozzle slew tests are now finished. There were no problems reported in any of the checks.

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

The upper stage engine steering checks have been completed. The first stage tests are next.

2200 GMT (6:00 p.m. EDT)

The engine slew tests have begun -- starting with the second stage RL10 engine.

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

The team is now preparing to conduct the steering checks of the Delta 4 rocket's engines.

2143 GMT (5:43 p.m. EDT)

Now 90 minutes from launch of Delta 4 and the Defense Satellite Communications System 3-B6 spacecraft for the U.S. Air Force. This will be the third Boeing Delta 4 mission and the second for the Air Force's Evolved Expendable Launch Vehicle program.

2136 GMT (5:36 p.m. EDT)

The Range is now "green" for launch. A couple of issues -- with a tracking station and some data lines -- have been successfully resolved.

2132 GMT (5:32 p.m. EDT)

Using launch pad cameras, engineers have completed a check of the rocket's thermal insulation as planned. A second evaluation will be performed over the next half-hour.

2130 GMT (5:30 p.m. EDT)

The RF link checks have been completed and verified acceptable.

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

Telemetry RF link checks have now started. The TEL-4 ground tracking station at the Cape has acquired the telemetry stream.

2125 GMT (5:25 p.m. EDT)

The latest check of the weather shows favorable conditions. Skies are mostly clear, great visibility, there are no showers around the Cape and ground winds are still well below the limit for launch. All in all, the weather should allow for a great view of the launch in less than two hours.

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

Reporters and photographers are now gathering at Cape Canaveral to cover this evening's launch.

2110 GMT (5:10 p.m. EDT)

To recap, the Delta 4 rocket is fueled up, the countdown is progressing smoothly, the weather is ideal and liftoff remains targeted for 7:13 p.m. EDT this evening from Cape Canaveral Air Force Station, Florida.

The Range is troubleshooting some issues but officials are hopeful the situation will be cleared up soon.

2052 GMT (4:52 p.m. EDT)

The launch team is looking at a couple of minor glitches. The Range is also working some hardware issues. However, at this time none of these items appear to be show-stoppers for this evening's launch attempt.

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

Engineers are preparing to conduct the countdown's evaluation of the Delta 4 rocket's thermal insulation following the loading of super-cold propellants into the vehicle.

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

The upper stage liquid hydrogen tank is now loaded. Checks will performed before topping commences.

So all four cryogenic propellant tanks on the Delta 4 have been loaded this afternoon. Launch is now two-and-a-half hours away.

2019 GMT (4:19 p.m. EDT)

Upper stage liquid oxygen loading is complete. Topping operations are upcoming.

There are no technical constraints being worked, the countdown is going very well and fueling work is running a bit ahead of schedule.

2008 GMT (4:08 p.m. EDT)

Filling the upper stage liquid oxygen tank continues.

The liquid hydrogen chilldown is nearing completion in preparation for loading the fuel into the stage -- the Delta 4 rocket's fourth and final cryogenic propellant tank to be filled during today's countdown.

1958 GMT (3:58 p.m. EDT)

Countdown clocks now read T-minus 3 hours and counting. Liftoff of the Boeing Delta 4-Medium rocket -- a two-stage, all-cryogenic vehicle with no strap-on solid fuel boosters -- remains set for 7:13 p.m. EDT this evening from pad 37B at Cape Canaveral carrying the Defense Satellite Communications System 3-B6 spacecraft for the Air Force.

The first stage liquid oxygen tank has been filled and topping is underway. The first stage liquid hydrogen tank has also been filled, with vent and relief checks upcoming.

For the upper stage, conditioning of the liquid oxygen system is finished. The loading is underway. The chilldown for the liquid hydrogen side is still being performed.

1954 GMT (3:54 p.m. EDT)

The first stage liquid oxygen tank is now being topped off.

Fueling operations have been proceeding smoothly and quietly this afternoon at Cape Canaveral.

1947 GMT (3:47 p.m. EDT)

The chilldown of the upper stage liquid oxygen system is being completed, clearing the way for loading the vehicle's tank.

1937 GMT (3:37 p.m. EDT)

With the first stage liquid hydrogen tanking in the "fast-fill" mode, the launch team has been given approval to begin chilldown conditioning of the upper stage liquid hydrogen system. This is a precursor to fueling the upper stage.

1933 GMT (3:33 p.m. EDT)

Launch Weather Officer Joel Tumbiolo has just provided a briefing to mission officials. He has improved the odds of meeting the launch weather rules this evening to 80 percent.

"We continue to be in real good shape," Tumbiolo reported. "I do continue to see favorable conditions for the remainder of the count."

The main concern that will be monitored over the next couple of hours will be cumulus clouds and the possibility of precipitation in them. Meanwhile, the ground winds are still well below the 15-knot limit.

1928 GMT (3:28 p.m. EDT)

The loading of liquid oxygen into the first stage is nearing completion. The launch team will be performing vent and relief checks following tanking and begin chilldown procedures for the upper stage liquid oxygen system.

1910 GMT (3:10 p.m. EDT)

The Delta 4 rocket's first stage is currently being loaded with super-cold liquid oxygen and liquid hydrogen propellants.

Complex 37 has two giant sphere-shaped fuel tanks to store the cryogenic liquid oxygen and liquid hydrogen. The LOX tank holds 250,000 gallons and LH2 sphere about 850,000 gallons. The tanks' large supplies should allow for at least three consecutive launch attempts before having to be replenished.

The cryogenics flow from the storage tanks, through pipes to the base of the pad. For the first stage, the propellants are routed up to the launch table upon which the rocket sits. Tail service masts, the large box-like structures at the base of the vehicle, feed the oxygen and hydrogen to the stage in separate umbilicals. The second stage receives its cryos from the middle swing arm that extends from the Fixed Umbilical Tower to the front-side of the rocket.

1858 GMT (2:58 p.m. EDT)

T-minus 4 hours and counting. The countdown rolls on for this evening's planned 7:13 p.m. EDT liftoff of the Delta 4 rocket. The count has a planned hold at T-minus 5 minutes for 15 minutes.

1851 GMT (2:51 p.m. EDT)

A "go" have been given to start slowly pumping liquid hydrogen propellant into the first stage. This "slow-fill" will be sped up to "fast-fill" after a small portion of the tank is loaded.

Chilled to Minus-423 degrees Fahrenheit, the liquid hydrogen will be consumed by the RS-68 main engine along with liquid oxygen during the first four minutes, 20 seconds of the launch.

1843 GMT (2:43 p.m. EDT)

First stage liquid oxygen tanking operation is about to transition from "slow-fill" to "fast-fill" mode.

Meanwhile, the cold gas chilldown conditioning of the liquid hydrogen system is continuing.

1830 GMT (2:30 p.m. EDT)

With the liquid oxygen pump and the first stage properly conditioned for cryogenic temperatures, the loading of Minus-298 degree LOX into the Delta 4 rocket's first stage has begun.

Delta program manager Dan Collins says the countdown is progressing very well this afternoon. There are no technical concerns, weather is favorable, the Range is up and operating and efforts to fuel the vehicle are underway.

1813 GMT (2:13 p.m. EDT)

The countdown is entering the final five hours to launch of the Boeing Delta 4 rocket carrying the Defense Satellite Communications System 3-B6 spacecraft from Cape Canaveral Air Force Station, Florida. Liftoff is planned to occur at 7:13 p.m. EDT this evening.

Work is on-going at pad 37B to ready for cryogenic tanking of the vehicle's two stages with liquid oxygen and liquid hydrogen.

All is going smoothly today in the countdown and the weather looks great at this hour.

1756 GMT (1:56 p.m. EDT)

A check of the ground winds at the launch pad shows that conditions are well within the 15-knot limit for liftoff. The winds are averaging around 10 knots or less over the past couple of hours.

1744 GMT (1:44 p.m. EDT)

The liquid oxygen pump chilldown is continuing for loading the Delta 4 rocket this afternoon. Also, the "go" has been given to start liquid hydrogen operations to prepare for fueling the vehicle.

1723 GMT (1:23 p.m. EDT)

The Blast Danger Area has been verified cleared of all workers and officials have given a "go" for fueling operations. Upcoming, the launch team will start thermal conditioning steps to ready equipment for pumping the super-cold liquid oxygen and liquid hydrogen propellants into the Delta 4 rocket today.

1713 GMT (1:13 p.m. EDT)

T-minus 5 hours, 45 minutes and counting! The second Terminal Count for this 301st launch of a Delta rocket has begun. With one planned hold at T-minus 5 minutes, liftoff is still set to occur at 7:13 p.m. EDT. The available launch window extends to 8:31 p.m. EDT.

There are no technical constraints being worked and the weather is favorable at this time.

As the count moves into the mid-afternoon, the launch team will be focused on loading the super-cold liquid hydrogen and liquid oxygen into both stages of the rocket.

Earlier today, the rocket's guidance computer -- the Redundant Inertial Flight Control Assembly, or RIFCA -- was powered up and data interrupt testing completed.

1659 GMT (12:59 p.m. EDT)

A poll of the various launch team members has been performed to ensure everyone is "ready" for continuing today's countdown. No issues were announced.

The countdown is presently holding at the T-minus 5 hour, 45 minute mark. The clocks will resume ticking in about 14 minutes as the Terminal Countdown starts.

1653 GMT (12:53 p.m. EDT)

MAN STATIONS. The launch team members are assembling at their consoles to support today's shot at flying Boeing's third Delta 4 rocket. Liftoff is scheduled for 7:13 p.m. EDT (2313 GMT) at the opening of a 78-minute launch window extending to 8:31 p.m. EDT (0031 GMT).

Launch Weather Officer Joel Tumbiolo has just provided a briefing to officials in advance of the Terminal Countdown beginning. Overall, the weather is looking pretty good today.

"We are in good shape, and I don't expect the scenario that we had yesterday," Tumbiolo said, referring to the tropical squalls that formed over the Atlantic and headed for the Cape.

"I expect to remain below the thresholds for tanking, vehicle exposure and launch," he reported a short time ago.

"I am still sitting at a 30 percent chance (of weather prohibiting launch). The main concern, I think, will be ground winds and maybe one or two rainshowers out over the ocean. As far as tanking and vehicle exposure, I see no concerns whatsoever."

1500 GMT (11:00 a.m. EDT)

Launch Weather Officer Joel Tumbiolo has issued is forecast for today's launch attempt. You can read the full forecast here.

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

Activities are underway at pad 37B this morning for a second shot at launching the Boeing Delta 4 rocket and DSCS 3-B6 communications satellite for the Air Force. The mobile service tower has again been retracted in support of launch, which is targeted for 7:13 p.m. EDT (2313 GMT) this evening from Cape Canaveral.

The Terminal Countdown will begin at 1:13 p.m., with fueling operations scheduled to commence a bit later in the afternoon.

Yesterday's initial launch attempt was scrubbed due to threatening weather conditions.

Read our earlier status center coverage.