BY JUSTIN RAY

Follow the preparations and launch of the Lockheed Martin-built Titan 4B rocket carrying the sixth and final Milstar military communications satellite. Reload this page for the very latest on the mission.

Video coverage for subscribers only:
   VIDEO: TITAN 4 ROCKET LAUNCHES WITH MILSTAR 6 QT NEW
   VIDEO: LAUNCH SCENES FROM PRESS SITE ON CAUSEWAY QT NEW
   VIDEO: RETROSPECTIVE VIDEO ON HISTORY OF TITAN QT
   VIDEO: PRE-LAUNCH NEWS CONFERENCE HELD SATURDAY QT
   VIDEO: FOOTAGE OF MILSTAR ASSEMBLY IN FACTORY QT
   VIDEO: MILSTAR SPACECRAFT SHIPPED TO THE CAPE QT
   VIDEO: SATELLITE ENCAPSULATED BY NOSE CONE QT
   VIDEO: ANIMATION OF MILSTAR ASCENT TO ORBIT QT
   PANORAMA: 360-DEGREE VIEW OF TITAN 4 ON THE PAD QT VR
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TUESDAY, APRIL 8, 2003

The final member of the U.S. military's most secure satellite communications constellation ascended into the sky Tuesday where it will relay highly sensitive information between the president and the armed forces. Read our full launch story.

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

Lockheed Martin says the power-generating solar arrays on the Milstar 6 spacecraft are deployed and onboard batteries are charging. The satellite is reported to be in great shape following today's launch on a 10-year mission of relaying communications for the U.S. government.

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

MISSION COMPLETE! Following the third firing of the Centaur upper stage to reach geostationary orbit, the Air Force's Milstar 6 communications satellite has been deployed to conclude today's launch. Indications show a successful mission was achieved, officials said.

We will have a post-launch wrap-up story later today.

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

T+plus 6 hours, 15 minutes. We'll be getting confirmation of the final Centaur burn and spacecraft separation in one announcement from officials coming up in a half-hour or so.

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

T+plus 1 hour, 18 minutes. The Centaur upper stage has completed its second firing of the mission, Lockheed Martin confirms.

The Centaur performed an initial burn following separation from the Titan second stage in order to achieve a parking orbit around Earth. This second firing was designed to raise one side of the orbit from the low-altitude parking orbit to geosynchronous altitude. The target orbit is approximately 22,239 statute miles at apogee, 128 miles at perigee and an inclination of 26.7 degrees to the equator.

The third burn, which is scheduled about five hours from now, will raise the low side of the orbit and reduce inclination. The target deployment orbit for Milstar today is circular at an altitude of approximately 22,210 statute miles and inclination of 4.5 degrees.

1403 GMT (10:03 a.m. EDT)

T+plus 20 minutes. The Centaur and Milstar are currently cruising at an altitude of 106 nautical miles. Lockheed Martin says the launch has gone very smoothly to this point. Two more firings of Centaur are left to go before Milstar is deployed into geostationary orbit some six hours and 34 minutes after liftoff.

We will pause our coverage at this point. Check back for confirmation of the upcoming Centaur second burn in about an hour.

1357 GMT (9:57 a.m. EDT)

T+plus 14 minutes. The Centaur upper stage and attached Milstar payload are now in a coast period. This will continue until T+plus 65 minutes and 31 seconds when the Centaur engines reignite for a scheduled four-minute burn to begin the two-step journey to geosynchronous orbit.

1354 GMT (9:54 a.m. EDT)

T+plus 11 minutes, 26 seconds. MECO 1. The Centaur engines have shut down as planned following the first of three firings needed to deliver the Milstar satellite into the proper geostationary orbit today.

1353 GMT (9:53 a.m. EDT)

T+plus 10 minutes, 30 seconds. The Centaur and attached Milstar spacecraft are headed to a parking orbit of approximately 111 statute miles at apogee, 105 miles at perigee and inclination of 28.6 degrees.

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

T+plus 9 minutes, 57 seconds. Centaur main engines have ignited. The upper stage is now firing to achieve a low-altitude parking orbit around Earth.

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

T+plus 9 minutes, 23 seconds. The Titan 4 rocket's second stage has shut down. Retrofire motors have fired and the spent stage has separated from the Centaur upper stage.

1351 GMT (9:51 a.m. EDT)

T+plus 8 minutes. About a minute left in the second stage burn. No problems have been reported by Lockheed Martin as the Titan streaks to space with Milstar 6.

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

T+plus 6 minutes, 30 seconds. Second stage performance reported normal. The liquid-fueled engine on the stage produces just over 100,000 pounds of thrust.

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

T+plus 5 minutes, 30 seconds. The first stage has completed its job and the spent stage has dropped away to fall into the Atlantic Ocean. The second stage liquid-fueled engine has now ignited.

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

T+plus 5 minutes, 5 seconds. First stage engine shutdown systems enabled. Coming up on engine cutoff.

1347 GMT (9:47 a.m. EDT)

T+plus 4 minutes, 30 seconds. Titan 4 continues on course.

1346 GMT (9:46 a.m. EDT)

T+plus 3 minutes, 40 seconds. The Air Force confirms separation of the 76-foot long payload fairing enclosing the Milstar spacecraft atop the Titan 4B rocket. First stage continues to fire.

1346 GMT (9:46 a.m. EDT)

T+plus 3 minutes. A good flight still being reported.

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

T+plus 2 minutes, 40 seconds. Solid rocket booster separation!

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

T+plus 2 minutes, 15 seconds. First stage main engine start. The liquid-fueled engine package is up and burning. The first stage produces about 550,000 pounds of thrust. Engine ignition is a precursor to burnout and separation of the twin solid rocket boosters that have propelled the Titan 4 rocket to this point in the flight.

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

T+plus 60 seconds. A smooth flight reported so far for this 35th flight of a Titan 4 rocket. Nearing area of maximum dynamic pressure.

1343 GMT (9:43 a.m. EDT)

T+plus 30 seconds. Both solid rocket motors burning normally to propel the Titan 4 rocket into the partly cloudy Florida morning sky. The Alliant Techsystems-built boosters are the providing the sole means of thrust for first two minutes and 11 seconds of flight before the liquid-fueled first stage is ignited.

1343 GMT (9:43 a.m. EDT)

T+plus 15 seconds. The launcher has cleared the tower at Cape Canaveral's Complex 40. The pitch and roll programs are now underway as the rocket maneuvers to the 93-degree flight azimuth for the trek downrange.

1343 GMT (9:43 a.m. EDT)

LIFTOFF! Liftoff of the Titan 4B rocket and Milstar 6 to complete the U.S. military's most technologically advanced telecommunications satellite constellation.

1342 GMT (9:42 a.m. EDT)

T-minus 1 minute. The Centaur guidance is transferring to inertial control. The guidance system switching to flight mode as the countdown enters the final moments to liftoff.

1341 GMT (9:41 a.m. EDT)

T-minus 80 second. The Flight Termination System has been armed. The ordnance will be armed in the next few seconds.

1341 GMT (9:41 a.m. EDT)

T-minus 2 minutes. The Centaur upper stage is switching from ground-fed power to internal batteries for launch. The vehicle's Flight Termination System is also transferring to internal power.

1340 GMT (9:40 a.m. EDT)

T-minus 2 minutes, 45 seconds. The Range recorders are operating.

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

T-minus 4 minutes. The Milstar spacecraft has been confirmed on internal power for flight.

1338 GMT (9:38 a.m. EDT)

T-minus 5 minutes and counting! The countdown sequence is now being controlled by the Programmable Aerospace Ground Equipment -- the PAGE computer system -- as the final minutes tick away for today's launch of Titan 4 B-35 and the final Milstar spacecraft from Complex 40 at Cape Canaveral Air Force Station, Florida.

1336 GMT (9:36 a.m. EDT)

The Air Force-controlled Eastern Range has given its final clear to launch!

1335 GMT (9:35 a.m. EDT)

Now eight minutes to launch.

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

The launch team status checks have been conducted with no issues announced. The countdown clock is scheduled to resume at 9:38 a.m. EDT.

1328 GMT (9:28 a.m. EDT)

T-minus 5 minutes and holding. The countdown has entered the planned 10-minute built-in hold. Readiness polls will be performed during this time to ensure all systems are "go" for liftoff at 9:43 a.m. EDT today. Lockheed Martin is not reporting any technical problems. The only worry is the local weather conditions.

1324 GMT (9:24 a.m. EDT)

The Centaur upper stage is filled super-cold liquid hydrogen and liquid oxygen for today's mission. The tanking operation was completed at 8:23 a.m. EDT, Lockheed Martin says. But due to the cryogenic nature of the propellants, the stage is replenished through the countdown to replace the supplies that boil away.

Meanwhile, engineers report that upper level winds have been verified acceptable through 10:18 a.m. EDT. A series of weather balloons are dispatched over the course of several hours leading up to the launch to ensure the conditions aloft are favorable for the rocket to fly through.

1323 GMT (9:23 a.m. EDT)

At liftoff the Titan 4B will be powered by the twin solid rocket motors, each producing 1.7 million pounds of thrust. Once the launch tower is cleared, the vehicle will perform pitch and roll maneuvers for positioning on the 93 degree flight azimuth for this launch. Titan will head eastward away from Cape Canaveral. After about a nine-minute flight, the Titan will deploy the Centaur upper stage and attached Milstar spacecraft. The high-energy Centaur will fire three times today, ultimately sending the Milstar 2-F4 satellite payload into a geostationary orbit. The entire flight will last about six hours and 34 minutes.

1318 GMT (9:18 a.m. EDT)

T-minus 15 minutes and counting. The countdown clocks are headed to T-minus 5 minutes where a 10-minute hold is planned. Launch is still set for 9:43 a.m. EDT. Lockheed Martin is not reporting any problems at this point.

1314 GMT (9:14 a.m. EDT)

Lockheed Martin reports weather conditions are now within limits for launch.

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

An Air Force spokesman says if the Titan 4 doesn't fly today, the next launch attempt won't come until April 14 due to a constraint on vehicle batteries.

Launch of the Lockheed Martin Atlas 3B rocket and AsiaSat 4 commercial communications satellite from the Cape is still set for Thursday evening.

1300 GMT (9:00 a.m. EDT)

With 40 minutes left until the opening of the window, low clouds are moving in. Lockheed Martin says "debris clouds" from thunderstorms off to the west caused the weather criteria to be "no go" for launch a short time ago. However, it is hoped that those clouds will clear out soon.

1240 GMT (8:40 a.m. EDT)

Good day from the NASA Causeway press site located a few miles from the Titan 4 rocket's launch pad. It is a pretty morning on Florida's Space Coast with just some high, thin clouds, a light breeze and warm temperatures. There are some storms to the west, so officials would like to get this launch off at the opening of the window at 9:43 a.m. EDT.

1135 GMT (7:35 a.m. EDT)

The countdown is ticking along at Cape Canaveral this morning. Lockheed Martin says liftoff remains on schedule for 9:43 a.m. EDT. Operations to load the Centaur upper stage with its supply of liquid oxygen and liquid hydrogen propellants is underway.

Weather conditions look generally favorable at this hour and there are no reports of any technical problems from launch spokespeople.

Our live play-by-play updates on the final countdown and flight of Titan 4 will begin around 9 a.m. EDT from the air station.

0730 GMT (3:30 a.m. EDT)

The 11.2 million pound, 260 foot tall mobile service tower is currently being retracted from around the Titan 4B rocket as the countdown continues for today's launch from Cape Canaveral's Complex 40.

The tower is a building on wheels. It is considered one of the largest and heaviest self-propelled structures in the world.

Over the next couple of hours, crews will lock the tower in its parked position and secure the pad facilities for launch. Once the complex is cleared of all personnel after sunrise, activities to fuel of the rocket's Centaur upper stage will commence.

0615 GMT (2:15 a.m. EDT)

The massive doors on the south-side of the mobile service tower are being swung open at this hour. This event is a precursor to rolling the tower into the launch position a little later. Today's launch window for the Titan 4B rocket and Milstar 6 spacecraft extends from 9:43 a.m. to 1:43 p.m. EDT.

MONDAY, APRIL 7, 2003

A second try to launch a Titan 4 rocket carrying the final Milstar spacecraft is scheduled for 9:43 a.m. EDT (1343 GMT) Tuesday from Cape Canaveral.

The Air Force said Monday that the issues from Sunday's scrubbed launch attempt have been resolved.

Watch this page for live updates during the final portion of Tuesday's countdown and the 6.5-hour flight of the Titan/Centaur rocket carrying Milstar 6.

1715 GMT (1:15 p.m. EDT)

Air Force forecasters are predicting a 60 percent chance of bad weather for Tuesday's launch opportunity and an 80 percent on Wednesday. See the forecast here.

Read our earlier Mission Status Center coverage.