BY JUSTIN RAY

Follow the preparations and launch of Boeing's Delta 4 rocket carrying the Air Force's DSCS A3 communications satellite. Reload this page for the very latest on the mission. Use our text only page for faster downloads.

0053 GMT (7:53 p.m. EST Mon.)

Delta 4 Launch Director Joy Bryant has given her final approval to resume the countdown.

0050 GMT (7:50 p.m. EST Mon.)

The Boeing console operators, launch director, the Range and weather officer have all reported "ready" to resume the countdown. Officials are taking this launch attempt right down to the wire with liftoff planned at the end of today's window at 7:59 p.m. EST.

0049 GMT (7:49 p.m. EST Mon.)

Now five minutes remaining in this hold. Standing by for another round of readiness polls of the launch team.

0045 GMT (7:45 p.m. EST Mon.)

The countdown is expected to restart from the T-minus 5 minute mark at 7:54 p.m.

0042 GMT (7:42 p.m. EST Mon.)

Engineers report the transmitter current alarm message is something that is understood and not a constraint to launch. With some tweaking, this issue has been cleared so it shouldn't stop the countdown again. Launch is set for 7:59 p.m. EST.

0040 GMT (7:40 p.m. EST Mon.)

NEW LAUNCH TIME. The launch team is preparing for one final attempt to get the Delta 4 off the ground today. Liftoff has been officially rescheduled for 7:59 p.m. EST -- the very end of the launch window.

0038 GMT (7:38 p.m. EST Mon.)

An official new launch time has not been announced. Troubleshooting continues.

0030 GMT (7:30 p.m. EST Mon.)

Efforts to resolve this problem continues. Today's launch window remains open until 7:59 p.m. EST. The countdown has been reset to T-minus 5 minutes and holding.

0025 GMT (7:25 p.m. EST Mon.)

Chief launch conductor Rick Navarro says the countdown has been recycled. The problem appears to be a "single sample glitch" in the telemetry that tripped a "special flight instrumentation transmitter external current alarm." The team is working the issue.

A launch time has not been officially retargeted.

0020 GMT (7:20 p.m. EST Mon.)

A preliminary launch time is being targeted for 7:45 p.m. However, work remains underway to understand the alarm which caused this hold and the resolution of the glitch.

0017 GMT (7:17 p.m. EST Mon.)

The Delta 4 rocket is back on external power.

0016 GMT (7:16 p.m. EST Mon.)

The countdown has been stopped after an alarm was tripped. Safing is in progress.

0015 GMT (7:15 p.m. EST Mon.)

T-minus 4 minutes, 21 seconds and holding. HOLD!!

0015 GMT (7:15 p.m. EST Mon.)

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

0015 GMT (7:15 p.m. EST Mon.)

T-minus 5 minutes and counting! The final phase of today's countdown is now underway at Cape Canaveral Air Force Station for launch of Boeing's Delta 4 rocket. Liftoff is set to occur at 7:20 p.m. EST (0020 GMT) from pad 37B.

0014 GMT (7:14 p.m. EST Mon.)

Countdown will restart in 60 seconds. Launch is six minutes away.

0011 GMT (7:11 p.m. EST Mon.)

Another poll of the launch team has been conducted to ensure there are no constraints to resuming the countdown. No issues were reported.

0007 GMT (7:07 p.m. EST Mon.)

The new launch time of 7:20 p.m. EST has been approved.

0005 GMT (7:05 p.m. EST Mon.)

The countdown, which was recycled back to T-minus 5 minutes and holding, should restart again at 7:15 p.m. EST. That would produce a liftoff of the Delta 4 rocket at 7:20 p.m. EST (0020 GMT).

0004 GMT (7:04 p.m. EST Mon.)

The chief launch conductor Rick Navarro reports the troubleshooting has been completed. The problem appears to be resolved. A new launch time is being targeted for 7:20 p.m. EST, following the final OK from the Range after clearing the restricted waters in the Atlantic.

MONDAY, MARCH 10, 2003
2357 GMT (6:57 p.m. EST)

The earliest liftoff can occur is 7:09 p.m. EST. There are three Collision Avoidance blackout times that prevent launch during three sections of today's window. Here are the periods when launch is allowed to happen:

• 6:42 to 6:59 p.m. EST
• 7:09 to 7:49 p.m. EST
• 7:51 to 7:59 p.m. EST

2356 GMT (6:56 p.m. EST)

The Range is making another sweep of the restricted area off the coast of Florida. That must be completed before the Delta 4 can fly. Meanwhile, the launch team is still assessing the low pressure problem that was seen on the helium purge to the main engine, which caused this hold.

2353 GMT (6:53 p.m. EST)

The DSCS A3 spacecraft cargo aboard the Delta 4 is reported ready for the resumption of the countdown. A new launch time has not been set.

2349 GMT (6:49 p.m. EST)

The hold was prompted due to a helium purge pressure problem to the RS-68 main engine of the Delta 4 rocket. Troubleshooting is underway.

2347 GMT (6:47 p.m. EST)

We are still awaiting confirmation from Boeing on what caused the hold to be called. There has been no announcement of a new launch time.

2345 GMT (6:45 p.m. EST)

The countdown was halted just after resuming from the T-minus 5 minute mark. The launch team has begun recyling steps.

2345 GMT (6:45 p.m. EST)

HOLD! The countdown clock has stopped!

2345 GMT (6:45 p.m. EST)

T-minus 5 minutes and counting! The Air Force's first Evolved Expendable Launch Vehicle mission is just minutes away. Liftoff of Boeing's Delta 4 rocket is set to occur at 6:50 p.m. EST (2350 GMT) from pad 37B at Cape Canaveral Air Force Station in Florida.

2344 GMT (6:44 p.m. EST)

Launch Director Joy Bryant has given her approval to resume the countdown at 6:45 p.m.

2344 GMT (6:44 p.m. EST)

NEW LAUNCH TIME. Liftoff is set for 6:50 p.m. EST. The Range is "go" after the problem was fixed.

2336 GMT (6:36 p.m. EST)

Liftoff has been delayed at least a few minutes due to the Range problem. There has been no announcement of a new liftoff time. Today's launch window extends to 7:59 p.m. EST.

2336 GMT (6:36 p.m. EST)

HOLD EXTENDED.

2335 GMT (6:35 p.m. EST)

Launch team members are working through the procedures in preparation for the last minutes of the count.

2334 GMT (6:34 p.m. EST)

The Boeing launch team and weather officer have been polled for a "go" to resume the countdown. No problems were reported. However, the Air Force-controlled Eastern Range is "no go" for launch due to a telemetry link issue. It is being worked. There has been no word if this will delay liftoff time.

2332 GMT (6:32 p.m. EST)

The Range is "no go" at this point due to a telemetry relay problem between two downrange stations.

2331 GMT (6:31 p.m. EST)

Standing by for the readiness poll of the launch team.

2327 GMT (6:27 p.m. EST)

The payload team reports the DSCS spacecraft atop the Delta 4 has been configured for launch.

2327 GMT (6:27 p.m. EST)

Now 15 minutes from launch time.

2322 GMT (6:22 p.m. EST)

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 6:42 p.m. EST.

2320 GMT (6:20 p.m. EST)

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.

2317 GMT (6:17 p.m. EST)

T-minus 10 minutes and counting. Standing by to enter the planned hold at T-minus 5 minutes.

2308 GMT (6:08 p.m. EST)

Today's 77-minute launch window has been broken up into three segments due to COLAs, or Collision Avoidance periods. The blackout periods prohibit liftoff during certain times to ensure the rocket isn't launched on a course that will take it too close to another object already in space.

The times in which the rocket can lift off today:

• 6:42 to 6:59 p.m. EST
• 7:09 to 7:49 p.m. EST
• 7:51 to 7:59 p.m. EST

2304 GMT (6:04 p.m. EST)

The Range tests are complete. The countdown continues smoothly with no issues being worked.

2259 GMT (5:59 p.m. EST)

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.

2257 GMT (5:57 p.m. EST)

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 6:42 p.m. EST.

2247 GMT (5:47 p.m. EST)

The RS-68 main engine spin start pressurization operation is being performed. Shortly, the Range Safety checks will occur.

2242 GMT (5:42 p.m. EST)

Now an hour away from the opening of today's launch window. That window extends for 77 minutes from 6:42 to 7:59 p.m. EST. Liftoff is still expected to happen on time.

2241 GMT (5:41 p.m. EST)

The slew test sequence for the Common Booster Core first stage main engine and the roll control nozzle is finished.

2235 GMT (5:35 p.m. EST)

The gimbal test of the upper stage engine has been completed with no problems reported.

2230 GMT (5:30 p.m. EST)

The engine steering tests have begun.

2224 GMT (5:24 p.m. EST)

The launch team is about to start the flight slews -- the engine nozzle gimbal tests -- in a couple of minutes.

2212 GMT (5:12 p.m. EST)

Now 90 minutes from launch of Delta 4 and the Defense Satellite Communications System 3-A3 spacecraft for the U.S. Air Force. This will be the second Boeing Delta 4 mission and the first for the Air Force's Evolved Expendable Launch Vehicle program.

2154 GMT (4:54 p.m. EST)

The launch team is projecting the upper stage engine fuel pump housing temperature should be within limits about an hour before liftoff time. If you recall, Saturday's launch was delayed into the window to await that temperature measurement to come within acceptable parameters for flight.

2147 GMT (4:47 p.m. EST)

T-minus 100 minutes and counting. All four cryogenic tanks on the first and second stages are currently in topping mode. Next up in the countdown will be engine steering checks in about 40 minutes. Liftoff still set for 6:42 p.m. EST.

2143 GMT (4:43 p.m. EST)

The telemetry link checks have been successfully performed.

2140 GMT (4:40 p.m. EST)

RF link checks are now beginning to verify the proper flow of telemetry data.

2120 GMT (4:20 p.m. EST)

Both cryo tanks of the first stage and the liquid hydrogen tank of the upper stage are in topping mode now. The replenishment to the upper stage liquid oxygen tank is about begin.

The next activity in the count will be telemetry link checks.

2112 GMT (4:12 p.m. EST)

Launch is now two-and-a-half hours away. Everything continues to proceed well in the countdown for liftoff at 6:42 p.m. EST from Cape Canaveral.

2101 GMT (4:01 p.m. EST)

The liquid oxygen tank of the upper stage has been loaded. All four of the rocket's cryo tanks have now been filled. Topping off will continue until very late in the countdown to replace the supplies that naturally boil away.

2037 GMT (3:37 p.m. EST)

The upper stage liquid hydrogen filling has been completed.

2032 GMT (3:32 p.m. EST)

Liquid oxygen loading for the upper stage is now beginning.

2030 GMT (3:30 p.m. EST)

Launch of Delta 4 is just over three hours away. Boeing is not reporting any technical problems as the countdown continues.

2022 GMT (3:22 p.m. EST)

The loading of liquid hydrogen into the upper stage has commenced. The first stage hydrogen tank has been filled.

Meanwhile, the first stage liquid oxygen tank is now in topping mode. The chilldown of upper stage liquid oxygen system has started in preparation for loading.

2001 GMT (3:01 p.m. EST)

Launch Weather Officer Joel Tumbiolo just gave a briefing to mission officials. He reports all conditions are currently acceptable. Ground winds are still the only concern -- a 20 percent chance of winds being too strong at launch time.

1958 GMT (2:58 p.m. EST)

Half of the first stage liquid hydrogen tank has been loaded to this point. Meanwhile, the upper stage liquid hydrogen chilldown has started.

1952 GMT (2:52 p.m. EST)

The first stage liquid oxygen tank is now full.

After some checks, preparations will start to load liquid oxygen into the upper stage.

1927 GMT (2:27 p.m. EST)

T-minus 4 hours and counting. Launch time is still set for 6:42 p.m. EST.

Fueling of the first stage continues in work with liquid hydrogen and liquid oxygen in "fast-fill" loading.

Complex 37 has two giant sphere-shaped fuel tanks to store the super-cold liquid oxygen and liquid hydrogen for Delta 4. 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.

1918 GMT (2:18 p.m. EST)

The "slow-fill" of first stage liquid hydrogen loading has been completed. The launch team is now switching to the "fast-fill" operation.

1916 GMT (2:16 p.m. EST)

First stage liquid oxygen tanking has transitioned from "slow-fill" to "fast-fill" mode.

1912 GMT (2:12 p.m. EST)

The loading of -298 degree liquid oxygen into the Delta 4 rocket's first stage has started in "slow-fill" mode.

1911 GMT (2:11 p.m. EST)

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 hydrogen will be guzzled by the RS-68 main engine along with liquid oxygen during the first four minutes, 20 seconds of the launch.

1858 GMT (1:58 p.m. EST)

The chilling of the first stage liquid oxygen system is nearing completion. The loading of LOX into the stage should begin shortly.

1845 GMT (1:45 p.m. EST)

The countdown is inside the final hours to launch of the Boeing Delta 4 rocket carrying the Defense Satellite Communications System 3-A3 spacecraft from Cape Canaveral Air Force Station, Florida. Liftoff is planned to occur at 6:42 p.m. EST -- the opening of a 77-minute launch window.

1835 GMT (1:35 p.m. EST)

Chilldown procedures are underway at launch pad 37B in advance of loading liquid oxygen and liquid hydrogen into the Delta 4.

1810 GMT (1:10 p.m. EST)

The latest updated weather forecast is posted here.

1750 GMT (12:50 p.m. EST)

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.

1742 GMT (12:42 p.m. EST)

T-minus 5 hours, 45 minutes and counting! The Terminal Countdown No. 2 for Delta 296 has begun. With one planned hold at T-minus 5 minutes, liftoff is still set to occur at 6:42 p.m. EST. The available launch window extends to 7:59 p.m. EST. There are no significant technical issues being reported at this time.

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

Launch Weather Officer Joel Tumbiolo give a briefing to managers a short time ago. There is some sea fog to the north of the Cape that could move around the pad later this afternoon, but that won't be a problem. The only weather worry for launch time will be ground winds.

1731 GMT (12:31 p.m. EST)

With liftoff just over six hours away, the launch team is now seated on console. A poll of the various team members was performed to ensure everyone was "ready" for continuing today's countdown. No issues were announced.

1642 GMT (11:42 a.m. EST)

The countdown has entered a planned hour-long hold at T-minus 5 hours, 45 minutes. Once clocks start ticking again, the Terminal Count will begin.

A little while ago, the Range Safety hold-fire checks were performed to ensure the countdown can be stopped in the final seconds if a problem is detected. And the work to turn on the rocket's avionics started.

1555 GMT (10:55 a.m. EST)

The launch weather forecast is still calling for an 80 percent chance of good conditions today. See the full forecast here.

1542 GMT (10:42 a.m. EST)

The main activities this morning was rolling back the mobile tower and securing the launch complex for today's countdown and liftoff of the Delta 4 rocket.

With the pad properly configured, workers clear the danger area in advance of hazardous operations such as fueling the rocket.

A Boeing spokesman says engineers have resolved the technical concerns that scrubbed Saturday's launch attempt. Also, technicians have patched some areas of foam insulation on the vehicle.

The Terminal Countdown is slated to begin two hours from now.

1315 GMT (8:15 a.m. EST)

The mobile service tower has been moved away from the Delta 4 rocket this morning as Boeing gets ready for another try at launching this $285 million Air Force Evolved Expendable Launch Vehicle mission.

Liftoff is scheduled for 6:42 p.m. EST (2342 GMT) today from Cape Canaveral's Complex 37B.

The 9-million pound, 330-foot tall tower shields the rocket from the weather, provides workers access to the various areas on the vehicle and is needed to hoist the payload atop the upper stage during the launch campaign.

Workers moved the structure back around the rocket early Sunday to protect the vehicle from storms that moved through the Central Florida area yesterday evening.

SUNDAY, MARCH 9, 2003
1911 GMT (2:11 p.m. EST)

Boeing has just issued a statement officially explaining the reason behind today's launch postponement.

"Boeing officials have delayed today's launch of a Delta 4 rocket due to a 70 percent chance of high winds up to 50 miles-per-hour in the Cape Canaveral area.

"The launch pad's mobile service tower has been rolled back to provide protection to the rocket and the satellite payload.

"Engineers have performed a thorough lock-down of the rocket and are using the extra time to make minor insulation repairs following last night's launch attempt.

"The next launch attempt is planned for Monday, March 10 with the 77-minute window opening at 6:42 p.m. EST."

1730 GMT (12:30 p.m. EST)

Our Launch Cue Card has been updated to reflect the new launch date. You can see it here.

1715 GMT (12:15 p.m. EST)

The weather forecast for Monday's launch opportunity calls for an 80 percent chance of good conditions. See the full forecast here.

1611 GMT (11:11 a.m. EST)

SCRUB. Today's launch attempt been called off. The tentative plan is to try again on Monday. We'll update this page when more details become available from Boeing.

1500 GMT (10:00 a.m. EST)

Boeing is preparing to make a second attempt to launch its Delta 4 rocket and the DSCS A3 communications satellite for the U.S. Air Force. Liftoff is scheduled for 6:43 p.m. EST (2343 GMT) from Cape Canaveral, Florida. The available launch window extends for approximately 77 minutes to 8:00 p.m.

However, the latest weather forecast, issued a short time ago by Launch Weather Officer Joel Tumbiolo, indicates a 70 percent chance of unacceptable conditions for liftoff. See the complete forecast here.

Saturday's countdown was scrubbed after a series of technical problems, which prevented launch before the close of the evening's window. The window is driven by the payload's requirements.

0600 GMT (1:00 a.m. EST)

The weather forecast for Sunday's launch opportunity can be seen here.

0105 GMT (8:05 p.m. EST Sat.)

The Delta 4 rocket will be drained of its super-cold liquid hydrogen and liquid oxygen propellants as safing activities continue. Liftoff is rescheduled for 6:43 p.m. EST Sunday.

Today's countdown got off to a late start due to problems readying the rocket for mobile service tower rollback. The launch team worked hard throughout the day to catch up.

After some glitches were resolved, launch was set for 7:45 p.m. EST. But a problem getting the rocket's propellant system secured caused the countdown to be halted at T-minus 3 minutes, 7 seconds.

Boeing's launch commentator announced the launch was scrubbed at that point, but later retracted that statement as the team worked to try again at the close of the evening's window at 8:01 p.m. EST.

Just as the count was to restart, a launch team member called another hold.

"We do not have confirmation that it is acceptable to manually change the redline (on the measurement parameter)," the member said.

So that officially brought the launch attempt to an end.

0056 GMT (7:56 p.m. EST Sat.)

Tonight's window is about to close, so no further attempts will be possible.

The launch team has been told to prepare for another attempt on Sunday evening. The mobile service tower will remain in the launch position overnight.

0056 GMT (7:56 p.m. EST Sat.)

Just as the countdown was to resume at T-minus 5 minutes, another HOLD was called by the launch team.

0056 GMT (7:56 p.m. EST Sat.)

HOLD!

0054 GMT (7:54 p.m. EST Sat.)

Another poll of the launch team has been performed and everyone reported "ready" to resume the countdown for another shot at getting this rocket airborne tonight.

0050 GMT (7:50 p.m. EST Sat.)

Countdown clocks will resume at 7:56 p.m. EST from the T-minus 5 minute mark. Liftoff would occur at the end of the window on 8:01 p.m. EST.

0050 GMT (7:50 p.m. EST Sat.)

LAUNCH AT 8:01 p.m.! Contrary to the announcement by Boeing of a scrub, the countdown is being reset at T-minus 5 minutes. The propellant securing problem was caused by an alarm that prevented the software system from kicking in. So the team has resolved the situation and setting up liftoff at 8:01 p.m. EST.

0049 GMT (7:49 p.m. EST Sat.)

WELL!!! It appears Boeing launch commentator's call of a scrub was premature! The launch team is trying to target liftoff at 8:01 p.m. EST.

0045 GMT (7:45 p.m. EST Sat.)

"We have no indication of start of CBC propellant securing at T-minus 212 seconds," a launch team member announced as the countdown clock was stopped. The CBC is the Common Booster Core first stage of the Delta 4 rocket.

0043 GMT (7:43 p.m. EST Sat.)

SCRUB. It's official. Boeing has scrubbed today's attempt to launch the Boeing Delta 4 rocket, the launch commentator says. There is not enough time to resolve this issue and recycle the countdown for another try before the launch window closes at 8:01 p.m. EST.

0043 GMT (7:43 p.m. EST Sat.)

Safing operations are now underway. This is likely a scrub for the day. Standing by for confirmation.

0042 GMT (7:42 p.m. EST Sat.)

The launch countdown has been stopped by the team after a problem was observed with the propellant securing.

0041 GMT (7:41 p.m. EST Sat.)

T-minus 3 minutes, 7 seconds and holding. HOLD! Countdown clock has stopped.

0041 GMT (7:41 p.m. EST Sat.)

T-minus 4 minutes and counting. Ordnance is being armed.

0040 GMT (7:40 p.m. EST Sat.)

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

0040 GMT (7:40 p.m. EST Sat.)

T-minus 5 minutes and counting! The Air Force's first Evolved Expendable Launch Vehicle mission is just minutes away. Liftoff of Boeing's Delta 4 rocket is set to occur at 7:45 p.m. EST (0045 GMT) from pad 37B at Cape Canaveral Air Force Station in Florida.

0039 GMT (7:39 p.m. EST Sat.)

Standing by to resume the countdown in one minute.

0037 GMT (7:37 p.m. EST Sat.)

Launch Director Joy Bryant has given her approval. Now 8 minutes away from liftoff.

0036 GMT (7:36 p.m. EST Sat.)

The Boeing launch team, Range and weather officer have been polled for a "go" to resume the countdown from T-minus 5 minutes at 7:40 p.m. and everyone gave their approval. Liftoff is officially scheduled for 7:45 p.m. EST.

0033 GMT (7:33 p.m. EST Sat.)

The final readiness polls of the launch team will be upcoming in the next few minutes. The countdown would then resume at 7:40 p.m. EST from the T-minus 5 minute mark for liftoff at 7:45 p.m. (0045 GMT) from Cape Canaveral, Florida.

If the countdown has to hold inside the final five minutes, there isn't expected to be enough time to recycle the clock and try again before the end of the window at 8:01 p.m. So this could be a one-shot deal to get the rocket off tonight or wait till tomorrow.

0031 GMT (7:31 p.m. EST Sat.)

Boeing is looking at a launch time of 7:45 p.m. EST.

0030 GMT (7:30 p.m. EST Sat.)

The launch team has cleared this antenna issue. So all systems are currently "go" for launch of Delta 4! There are 31 minutes remaining in today's launch window.

0024 GMT (7:24 p.m. EST Sat.)

The alarm is associated with some electronics for the S-band system, a Boeing spokesman says.

0020 GMT (7:20 p.m. EST Sat.)

The fuel pump temperature is now within acceptable parameters for launch!

However, the launch team is now examining an alarm they recently received.

0015 GMT (7:15 p.m. EST Sat.)

Once the temperature issue comes within limits, the launch team will go through the remaining activities planned at the T-minus 5 minute hold -- such as readiness polls and other scripted chores. Again, tonight's launch window extends to 8:01 p.m. EST. A new launch time remains undetermined.

0009 GMT (7:09 p.m. EST Sat.)

The launch team is told that the RL10B-2 fuel pump housing temperature continues to decrease. Officials are just waiting for it to come within limits.

Engineers are also discussing a ground parameter for pressure monitoring associated with the Common Booster Core liquid hydrogen system. However, this is not expected to be a constraint to flight.

SATURDAY, MARCH 8, 2003
2357 GMT (6:57 p.m. EST)

To recap, the countdown remains holding at T-minus 5 minutes. Engineers are watching a temperature measurement on the upper stage fuel pump housing. Boeing is waiting for the temperature to come within limits. Weather conditions, although not the best for spectators watching the launch, is reported acceptable tonight. A new launch time remains uncertain. The team has until 8:01 p.m. to launch the Delta 4.

2349 GMT (6:49 p.m. EST)

An Air Force spokesman has announced at the press site that the new target liftoff time is 7:11 p.m. EST. However, that is quite tentative. The launch team is also monitoring the temperature of the second stage fuel pump housing.

2348 GMT (6:48 p.m. EST)

The DSCS spacecraft atop the rocket has been verified "go" for launch through tonight's window, which extends to 8:01 p.m. EST.

2344 GMT (6:44 p.m. EST)

Today's launch window is now open. There has been a delay in the liftoff time due to problems readying the rocket for rollback of the mobile service tower this morning. That slipped countdown activities a couple of hours.

The launch team is also assessing the second stage fuel pump housing temperature that is not coming down as quickly as expected, a Boeing spokesman says.

2342 GMT (6:42 p.m. EST)

The Boeing launch team has been told that all delayed countdown work has now been completed. Engineers are looking at the second stage fuel pump housing temperature. A new launch time has not been set.

2336 GMT (6:36 p.m. EST)

Launch Weather Officer Joel Tumbiolo reports all conditions are "go" and expected to remain that way through the window. The cloud conditions are safe for the rocket to fly through, the rainshowers remain away from the pad area and winds are below the 16-knot limit.

2329 GMT (6:29 p.m. EST)

The Air Force-controlled Eastern Range is now performing 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.

2327 GMT (6:27 p.m. EST)

The RS-68 main engine spin start pressurization operation is now underway. Meanwhile, Range Safety checks are about to start.

2324 GMT (6:24 p.m. EST)

T-minus 5 minutes and holding. Today's countdown has entered a hold that was supposed to last 15 minutes. Because of the need to catch up on work running behind schedule, this hold will be extended.

Once all activities are back on track, the launch team will resume the countdown for launch. Boeing has until 8:01 p.m. EST to get the rocket airborne tonight.

2322 GMT (6:22 p.m. EST)

T-minus 7 minutes and counting. Standing by to enter the planned hold at T-minus 5 minutes.

2321 GMT (6:21 p.m. EST)

The first stage steering checks have been performed. No problems reported in any of the slew tests.

2314 GMT (6:14 p.m. EST)

The upper stage engine steering checks have been completed.

2309 GMT (6:09 p.m. EST)

A Boeing spokesman says the launch team is looking at 7:22 p.m. EST as the new target liftoff time today.

2307 GMT (6:07 p.m. EST)

The engine slew tests have begun.

Due to the several-hour delay this morning rolling back the mobile service tower, the countdown timeline has been changed today to make up for lost time. All in all, the launch team has made up much of that time. But some slippage of the liftoff time into today's available 77-minue launch window is expected.

2305 GMT (6:05 p.m. EST)

The RF link checks have been completed and verified acceptable. The team will now move into the engine steering checks.

2303 GMT (6:03 p.m. EST)

The TEL-4 ground station at the Cape has acquired the telemetry stream.

2300 GMT (6:00 p.m. EST)

Topping of the upper stage liquid hydrogen tank is about to start.

And now the launch team is preparing to start RF telemetry link checks. The test to ensure the flow of telemetry data from the rocket to the ground during flight.

2251 GMT (5:51 p.m. EST)

Both tanks of the first stage and upper stage liquid oxygen tank are currently in topping off to replenish the supplies that naturally boil away. The upper stage hydrogen tank will enter topping shortly.

2244 GMT (5:44 p.m. EST)

Now an hour away from the opening of today's launch window. That window extends for 77 minutes from 6:44 to 8:01 p.m. EST, one minute shorter than previously announced by the Air Force. The launch team is looking at delaying liftoff past 6:44 p.m. However, an official launch time has not been announced.

2236 GMT (5:36 p.m. EST)

"We are looking in real good shape," Launch Weather Officer Joel Tumbiolo just told the launch management team. Meteorologists report all the cloudiness over the Cape is thin and low in altitude -- below the freezing level. There are some showers in the area being watched. But at this time, all weather rules are currently "go" for launch.

So the view might not be great for spectators but conditions should be within limits for the rocket to fly.

2234 GMT (5:34 p.m. EST)

The liquid hydrogen tank of the upper stage has now been filled. With loading of all four of the rocket's cryo tanks completed, the topping off will continue until very late in the countdown.

The launch team will soon begin working on RF link checks, steering checks of the rocket's nozzles and then Range Safety checks. The countdown clocks will enter a planned hold at T-minus 5 minutes. That hold is scheduled to last 15 minutes. However, officials are looking to extend the hold to give the team more catch-up time.

Any hold extension will delay liftoff time into today's window, which extends to 8:01 p.m. EST tonight.

2229 GMT (5:29 p.m. EST)

The upper stage liquid hydrogen tank is now 88 percent full.

2224 GMT (5:24 p.m. EST)

News reporters have arrived at their viewing location on the NASA Causeway -- to the southwest of pad 37B. The weather report is quite gloomy with dark clouds all around and difficulty clearly seeing the rocket a few miles away.

The radar shows some rainshowers further to the southwest of the Cape and lots of cloud cover. This is all thanks to a frontal system over Central Florida.

2214 GMT (5:14 p.m. EST)

Now 90 minutes from launch of Delta 4 and the Defense Satellite Communications System 3-A3 spacecraft for the U.S. Air Force. This will be the second Boeing Delta 4 mission and the first for the Air Force's Evolved Expendable Launch Vehicle program.

The launch team is not reporting any significant issues as fueling operations near the finish line. The weather is being monitored closely. There are still a lot of clouds around the Cape at this hour.

2159 GMT (4:59 p.m. EST)

Chilldown for the upper stage liquid hydrogen system has been completed. Work will now begin to load the stage -- the Delta 4 rocket's fourth and final cryogenic propellant tank to be filled during today's countdown.

Launch remains targeted for 6:44 p.m. EST.

2155 GMT (4:55 p.m. EST)

The loading of liquid oxygen into the upper stage is now being reported complete by the launch team.

2150 GMT (4:50 p.m. EST)

The first stage liquid hydrogen tank is nearing the 98 percent level. Topping of the stage's liquid oxygen tank is underway.

2132 GMT (4:32 p.m. EST)

The upper stage liquid oxygen tanking work is now beginning.

2119 GMT (4:19 p.m. EST)

The filling of the first stage liquid oxygen tank has been finished. After some checks, preparations will start to load liquid oxygen into the upper stage.

Meanwhile, the first stage liquid hydrogen tank is about half-full this far.

2115 GMT (4:15 p.m. EST)

The launch team reports the loading of the -298 degree liquid oxygen into the first stage is nearing completion.

2110 GMT (4:10 p.m. EST)

Fueling of the first stage continues with no problems reported.

Complex 37 has two giant sphere-shaped fuel tanks to store the super-cold liquid oxygen and liquid hydrogen for Delta 4. 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.

2057 GMT (3:57 p.m. EST)

First stage liquid hydrogen "slow-fill" is complete and the launch team has started "fast-fill" operations.

The first stage hydrogen tank is the largest of the orange foam-covered areas of the rocket, accounting for about two-thirds of the first stage. The oxygen tank is the middle orange band on the vehicle.

2048 GMT (3:48 p.m. EST)

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 hydrogen will be guzzled by the RS-68 main engine along with liquid oxygen, to be loaded shortly.

2044 GMT (3:44 p.m. EST)

Now three hours till the opening today's launch window. Final preparations are being made to start fueling the first stage of the Delta 4 rocket. That will be following by loading the upper stage a little later this afternoon.

2005 GMT (3:05 p.m. EST)

Launch Weather Officer Joel Tumbiolo just gave a briefing to mission officials. He reports all conditions are currently acceptable. The clouds over the launch site aren't thick at the present time. There are some rainshowers both to the north and southwest of the pad but not a concern. Winds are also below the 16-knot limit for launch.

Overall, Tumbiolo is still predicting a 60 percent chance of meeting the launch weather rules during today's window. Thick layered clouds, rainshowers and ground winds are the key worries, he noted.

1957 GMT (2:57 p.m. EST)

The chilldown procedures are beginning to thermally condition the first stage liquid hydrogen and liquid oxygen systems in advance of loading the cryogenics into the vehicle.

1952 GMT (2:52 p.m. EST)

Final clearing of workers from the launch pad area has just been announced.

1945 GMT (2:45 p.m. EST)

There's not much to report at this point as the launch team awaits confirmation that the Blast Danger Area is clear. Once that milestone is achieved, activities related to loading liquid oxygen and liquid hydrogen propellants into the Delta 4 can begin.

1915 GMT (2:15 p.m. EST)

The mobile service tower is locked down and the final workers are leaving the pad. Fueling operations should begin in the near future.

Meanwhile, the launch team has been working through the procedures to activate the rocket's avionics and S-band and C-band systems.

1900 GMT (2:00 p.m. EST)

The launch team has entered the final five hours of the countdown to the launch of Boeing's second Delta 4 rocket from Cape Canaveral Air Force Station's Complex 37B. Work to configure the pad for launch is continuing before all workers depart the hazard area.

1821 GMT (1:21 p.m. EST)

The 9-million pound mobile service tower is slowly rolling away from the Boeing Delta 4 rocket at Cape Canaveral's launch pad 37B.

The wheeled structure moved along European-style rail tracks to a position about the length of a football field from the launch table.

The 330-foot tall tower shields the rocket from the weather, provides workers access to the various areas on the vehicle and is needed to hoist the payload atop the upper stage during the launch campaign.

Once the tower is fully retracted in the next few minutes, crews will then secure the complex for launch before leaving the danger area around the pad. All workers must be clear of the area in preparation for the start of hazardous operations, including fueling the vehicle.

Although tower rollback is running several hours late, controllers report that the Delta 4 should still be ready for flight at the opening of its launch window.

1744 GMT (12:44 p.m. EST)

T-minus 5 hours, 45 minutes and counting! The Terminal Countdown has begun for today's launch of the Boeing Delta 4 rocket. With one planned hold at T-minus 5 minutes, liftoff is still targeted to occur at 6:44 p.m. EST.

Pre-launch preparations are running several hours behind schedule due to issues closing out sections of the rocket for flight. But that work is now complete. Workers are preparing to get the pad's mobile service tower rolled away from the Delta 4 and into the launch position shortly.

After the Complex 37 area is cleared of all personnel, the launch team will begin the activities to load liquid hydrogen and liquid oxygen into both stages of the rocket.

Boeing says there should be enough slack time in the countdown to compensate for the earlier delays, permitting an on-time liftoff today.

Today's available launch window extends for either 77 or 78 minutes -- the Air Force and Boeing windows don't match. A preliminary Collision Avoidance period has been reported by the Air Force that would prohibit liftoff between 7:15:31 and 7:24:44 p.m. EST. The COLA launch window cutouts ensure the rocket isn't launched at a time that would allow it to pass too close to another orbiting object.

1735 GMT (12:35 p.m. EST)

The game plan for this afternoon is to get the mobile service tower rolled back shortly, followed by pad securing and clearing the complex of all personnel. Fueling operations won't commence until the pad is cleared. At this point, officials are hopeful of still making an on-time launch at 6:44 p.m. EST today.

1731 GMT (12:31 p.m. EST)

The launch team has reported on console and ready for continuing today's countdown. Work at the pad remains focused on getting the Delta 4 rocket closed out and mobile tower rolled back.

1708 GMT (12:08 p.m. EST)

A Boeing spokesman says the launch team delayed tower rollback this morning to purpose some sort of extra test on the Delta 4 rocket. That evaluation has been successful, clearing the way for the late tower retraction and launch today.

1700 GMT (12:00 p.m. EST)

The latest launch weather forecast, issued this morning by weather officer Joel Tumbiolo, can be seen here.

1644 GMT (11:44 a.m. EST)

T-minus 5 hours, 45 minutes and holding. Clocks have entered a planned one-hour hold prior to entering Terminal Count. The rocket remains shrouded by the mobile service tower. Boeing has not yet said what has delayed this morning's rollback of the massive structure, which needs to be moved back and secured in order for the continuation of the launch preparations.

1625 GMT (11:25 a.m. EST)

The mobile service tower has still not rolled back this morning at launch pad 37B. We're standing by for an update from Boeing on the reason behind the delay and what impact, if any, this might have on today's launch attempt.

1500 GMT (10 a.m. EST)

A Boeing spokesman says preparations to retract the mobile service tower from around the Delta 4 rocket is running behind schedule, with motion not expected for another hour or more.

As far as the weather is concerned, it is a very cloudy morning in Central Florida courtesy of a frontal system hanging over the area. The radar indicates there are showers around and a larger cluster offshore to the east of Cape Canaveral.

FRIDAY, MARCH 7, 2003

Boeing and the Air Force report that the launch of Delta 4 and DSCS A3 communications spacecraft remains on schedule for Saturday at 6:44 p.m. EST (2344 GMT). The launch window extends for 78 minutes to 8:02 p.m. EST (0102 GMT).

The countdown clocks will begin ticking at 10:24 a.m. EST. At Complex 37B, crews will be rolling the mobile service tower away from the Delta 4 rocket and securing the pad for liftoff. The Terminal Count will commence at 12:44 p.m., followed by the fueling operations around 2:15 p.m.

This is the first Air Force Evolved Expendable Launch Vehicle program mission, capping a four-year effort of bringing the next-generation Delta 4 to the launch pad for government flights.

"Saturday marks a fairly major event for the partnership between Boeing and the U.S. Air Force -- it marks the completion of the development program for the Delta 4," said Col. Susan Mashiko, the EELV program director. "Once we get that rocket off the ground, I will make the final milestone payment on that development contract."

The Delta 4-Medium vehicle, valued at roughly $75 million according to the Air Force, will deploy the $210 million DSCS spacecraft into geosynchronous transfer orbit about 42 minutes after liftoff.

The satellite should enter service this summer, joining the constellation of DSCS spacecraft that provides worldwide communications relay services for the military and government officials.

"This is an extremely important payload to launch tomorrow," said Christine Anderson, the DSCS program manager. "The DSCS bird provides anti-jam, beyond line-of-sight communications to tanks in the Army, ships in the Navy and aircraft for the Air Force, as well as services for the president and secretary of defense."

Watch this page for countdown updates starting with tower rollback Saturday morning.

1600 GMT (11:00 a.m. EST)

The final readiness reviews are being conducted today by senior managers in preparation for tomorrow's launch of the Boeing Delta 4 rocket and DSCS A3 satellite for the Air Force.

Meteorologists are still calling for a 40 percent chance of bad weather during the launch window. You can read the latest forecast here.

A pre-launch news conference is scheduled for this afternoon. We'll post a complete countdown preview on this page later tonight. And watch this page for updates throughout the day tomorrow.

THURSDAY, MARCH 6, 2003
1630 GMT (11:30 a.m. EST)

The latest launch weather forecast, issued this morning by weather officer Joel Tumbiolo, can be seen here.

0501 GMT (12:01 a.m. EST)

Boeing's Delta 4 rocket enters U.S. military service this weekend to launch a $210 million relay satellite for the government's national security communications network. Read our full launch preview story.

WEDNESDAY, MARCH 5, 2003

The launch team will hold a mission dress rehearsal Thursday as a simulation exercise in advance of Saturday's flight of Delta 4.

Although two minor bugs are still being addressed, Boeing officials remain hopeful the rocket will fly duing Saturday's launch opportunity.

The final launch readiness reviews -- one by Boeing, one by the Air Force -- will occur on Friday to give approval for entering the countdown early Saturday.

The launch window extends from 6:44 to 8:02 p.m. EST for liftoff from Cape Canaveral's pad 37B carrying the DSCS A3 military communications satellite.

Watch this page for continuing updates on the launch preparations. And this is the place to look for comprehensive reports throughout the countdown and 42-minute flight of the Delta 4 rocket.