BY JUSTIN RAY

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

WEDNESDAY, JANUARY 16, 2002

The U.S. military on Tuesday launched the final link that will form a "golden ring" of communications satellites around Earth, providing ultra-secure, jam-resistant transmissions for troops and government leaders virtually anywhere on the planet. Read our full launch story.

And we have several video clips for our Spaceflight Now Plus subscribers of this Titan 4 mission:

Video coverage for subscribers only:

   PANORAMA: 360-DEGREE VIEW OF ROCKET ON THE PAD QT VR
   VIDEO: TITAN 4 ROCKET BLASTS OFF WITH MILSTAR 5 QT or RV
   VIDEO: MILSTAR IS ENCLOSED BY TITAN NOSE CONE QT or RV
   VIDEO: SERVICE TOWER RETRACTED FOR LAUNCH QT or RV
   MORE: COMPLETE SFN+ VIDEO INDEX

0746 GMT (2:46 a.m. EST)

SUCCESS DECLARED! The $800 million Milstar communications satellite has been delivered into orbit successfully today by the $453 million Titan 4B-Centaur rocket, the U.S. Air Force has just announced.

We will have a final wrap-up story on the launch momentarily.

0645 GMT (1:45 a.m. EST)

T+plus 6 hours, 15 minutes. It ain't over till it's over. And there is still two crucial events left to go in tonight's launch before success can be declared. The third and final burn by Centaur is scheduled to occur in about 10 minutes. Deployment of the Milstar 5 will follow at about 2:05 a.m. EST.

Confirmation that the proper orbit has been successfully achieved and spacecraft separation will come from the Air Force in one announcement. We'll post the information here as soon as it becomes available.

0200 GMT (9:00 p.m. EST)

T+plus 90 minutes. The Centaur upper stage has completed its second firing tonight and officials report all continues to go well for this launch.

The Centaur performed a 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 third burn scheduled about five hours from now will raise the low side of the orbit, thereby circularizing the orbit at 22,300 miles above the planet's equator.

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

T+plus 20 minutes. The Centaur and Milstar continue their quiet coast around Earth at altitude of 105 nautical miles. Officials report the launch has gone very smoothly to this point. But the flight won't be completed until Milstar is deployed into geostationary orbit some six hours and 35 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.

0044 GMT (7:44 p.m. EST)

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 two seconds when the Centaur engines reignite for a scheduled five-minute burn to begin the two-step journey to geosynchronous orbit.

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

T+plus 11 minutes, 45 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.

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

T+plus 9 minutes, 55 seconds. Centaur main engines have ignited. The upper stage is now firing to achieve a low-altitude parking orbit around Earth.

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

T+plus 9 minutes, 30 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.

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

T+plus 8 minutes, 30 seconds. Second stage engine shutdown systems enabled.

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

T+plus 8 minutes. About a minute left in the second stage burn.

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

T+plus 7 minutes, 10 seconds. The second stage continues to perform as planned, pushing the Milstar spacecraft to orbit. The engine produces just over 100,000 pounds of thrust.

0035 GMT (7:35 p.m. EST)

T+plus 5 minutes, 50 seconds. Altitude 86 miles, downrange distance 330 miles, velocity 16,670 fps.

0035 GMT (7:35 p.m. EST)

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.

0035 GMT (7:35 p.m. EST)

T+plus 5 minutes. First stage engine shutdown systems enabled. Coming up on engine cutoff in 25 seconds.

0034 GMT (7:34 p.m. EST)

T+plus 4 minutes, 10 seconds. Altitude 61 miles, downrange distance 140 miles, velocity 10,150 feet per second.

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

T+plus 3 minutes, 50 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.

0032 GMT (7:32 p.m. EST)

T+plus 2 minutes, 45 seconds. There they go -- the two solid rocket boosters have separated from the Titan 4 rocket's core as planned.

0032 GMT (7:32 p.m. EST)

T+plus 2 minutes, 20 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.

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

T+plus 1 minute, 40 seconds. A good burn of the solid rocket boosters is still reported by launch officials. They will fire for another minute or so before burning out of propellant and jettisoning.

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

T+plus 60 seconds. A smooth flight reported so far for this 34th flight of a Titan 4 rocket. Nearing area of maximum dynamic pressure.

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

T+plus 45 seconds. The vehicle has gone supersonic.

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

T+plus 30 seconds. Both solid rocket motors burning normally to propel the Titan 4 rocket into the Florida night 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.

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

T+plus 15 seconds. Vehicle has cleared the tower, and the pitch and roll programs are underway as the rocket maneuvers onto the proper heading for the flight downrange.

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

LIFTOFF! Liftoff of the first launch of 2002 as the Titan 4B rocket clears the tower with the Milstar 5 communications satellite -- a U.S. military switchboard in the sky.

0029 GMT (7:29 p.m. EST)

T-minus 35 seconds. Guidance system switching to flight mode as the countdown enters the final moments to liftoff.

0029 GMT (7:29 p.m. EST)

T-minus 1 minute. Centaur guidance system is transferring to inertial control.

0028 GMT (7:28 p.m. EST)

T-minus 2 minutes. The Centaur upper stage is now switching from ground-fed power to internal battery power for launch.

0027 GMT (7:27 p.m. EST)

T-minus 2 minutes, 30 seconds. The Range recorders are running.

0026 GMT (7:26 p.m. EST)

T-minus 4 minutes and counting. Lockheed Martin reports the Milstar spacecraft is being verified on internal power.

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

T-minus 5 minutes and counting. Clocks have resumed ticking. The Terminal Countdown begins at this time for the launch of Titan 4 B-38 and the fifth Milstar spacecraft from Cape Canaveral Air Force Station on Florida's east-central coast. The countdown sequence is now being controlled by the Programmable Aerospace Ground Equipment -- the PAGE computer system.

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

The launch team is preparing to pick up the countdown in one minute.

0022 GMT (7:22 p.m. EST)

The Air Force-controlled Eastern Range has given its final clearance to launch the Titan 4B rocket today. Built by Lockheed Martin, the Titan 4B is the most powerful in America's unmanned rocket fleet.

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

Five minutes left in this scheduled hold. Now 10 minutes away from launch.

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

T-minus 5 minutes and holding. Countdown clocks have stopped for this planned 10-minute hold. During this period, final readiness checks will be performed by the launch team to ensure all systems are "go" for today's mission.

At present there are no issues being addressed, the Air Force says. Liftoff remains scheduled for 7:30 p.m. EST (0030 GMT) from Complex 40 at Cape Canaveral Air Force Station in Florida.

The weather is favorable and the computer models of the toxics resulting from an explosion early in the launch indicate the hazardous cloud would not threaten populated areas.

0010 GMT (7:10 p.m. EST)

T-minus 10 minutes and counting. Clocks will be stopping at T-minus 5 minutes for the planned 10-minute built-in hold. No problems are currently being reported by the launch team and the weather remains favorable. Launch still targeted for 7:30 p.m. EST.

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

The countdown clocks continue ticking down with no problems to report.

Today's launch will mark the 34th for a Titan 4 rocket dating back to 1989 and the 12th flight of the newer Titan 4B model. It will be the 14th mission of a liquid-fueled Centaur upper stage on a Titan 4. And this is the 23rd Titan 4 to launch from Cape Canaveral, the 13th from Complex 40.

0000 GMT (7:00 p.m. EST)

Now a half-hour away from the planned liftoff time. At this point, controllers are scheduled to 'power on' the Milstar satellite nestled in the nose cone atop the Titan 4B rocket.

2350 GMT (6:50 p.m. EST)

T-minus 30 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 7:30 p.m. EST.

The Titan 4B rocket is now fully fueled for its Earth-shaking liftoff. The vehicle weighs about 2,074,000 pounds at present with the Milstar satellite cargo atop the massive launcher.

The two stages of the Titan's central core vehicle was loaded previously with storable hypergolic Aerozine 50 and nitrogen tetroxide propellants. The liquid-fueled Centaur upper stage was filled cryogenic liquid oxygen and liquid hydrogen over the past hour or so. The large white rocket motors strapped to Titan are solid-propellant.

Read the fact sheet for a description of the rocket -- the most powerful in America's unmanned fleet.

Also at this point in the countdown, Range Safety is completing the final checks of the command destruct receivers that would be used to destroy the Titan rocket should it veer off course or experience a problem during launch today.

2340 GMT (6:40 p.m. EST)

There is $1.3 billion on the line here as the Titan 4B rocket lifts off with the fifth Milstar military communications satellite in about 50 minutes.

During yesterday's pre-launch news conference, Christine Anderson, the director of Military Satellite Communications at the Air Force's Space and Missile Systems Center, aptly described the remarkable feat of launching this massive satellite aboard America's mightiest rocket.

"To put it into prospective of what we are going to be doing...(Milstar) is about the size of a Greyhound bus, the wing span is about what a 747 wing span would be, we are going to be launching that up to about 22,000 miles and it is going to stay up there for a period of about 10 years. So if that is not rocket science, I don't know what is."

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 tonight, ultimately sending the Milstar 2-F3 satellite payload into a geostationary orbit. The entire flight will last about six hours and 35 minutes.

2325 GMT (6:25 p.m. EST)

Air Force Launch Weather Officer Johnny Weems has just completed a weather briefing for the launch team. Weems reported that conditions are currently favorable at the Cape and forecast to remain that way for liftoff this evening. Most of the clouds have cleared out of the area, there is no rain around and the upper level winds, which have been erratic earlier today, have stabilized.

The launch time forecast calls for a few clouds at 3,000 and 14,000 feet, 7 miles visibility, north-northwesterly winds from 340 degrees at 10 to 20 knots and a temperature of 60 degrees F.

Should the launch be delayed to Wednesday or Thursday for some reason, there is a 90 percent chance of good weather both days.

2315 GMT (6:15 p.m. EST)

Powerful flood lights situated around Complex 40 are illuminating the Titan 4B rocket on its launch pad, making the 19-story vehicle visible for miles around. Vapors from the cryogenic liquid oxygen of the Centaur upper stage are gently streaming away from the port holes just beneath the rocket's nose cone as these final stages of the countdown tick along for the scheduled 7:30 p.m. EST (0030 GMT) blastoff from Cape Canaveral Air Force Station, Florida.

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

T-minus 80 minutes and counting. With one built-in hold scheduled into the countdown -- a 10 minute hold at T-minus 5 minutes -- launch is now an-hour-and-a-half away at 7:30 p.m. EST (0030 GMT). Fueling of the Centaur upper stage continues.

All weather rules are currently being met and no technical problems are being reported by the Air Force.

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

Launch of the $453 million Titan 4B rocket and the $800 million Milstar 5 spacecraft is now two hours away. The sun is beginning to set here in east-central Florida. The weather has improved dramatically from earlier in the day when it was gloomy, cloudy and rainy. The skies are now clear with a very light wind and comfortable temperatures.

At Complex 40 the computer-controlled process of fueling the Centaur upper stage is now underway. Super-cold liquid oxygen is currently being pumped into stage. Liquid hydrogen tanking will commence once oxygen loading is completed.

At this point, there are no problems being reported by the launch team. Range Safety is now "go" for liftoff; the toxics models now indicate acceptable conditions for launch.

2215 GMT (5:15 p.m. EST)

Sources say the Range is now green, indicating the threat to the populated areas from toxic gases in the event of a launch accident has diminished. The current launch time remains 7:30 p.m. EST (0030 GMT). The launch window tonight closes at 8:48 p.m. EST.

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

NEW LAUNCH TIME. The Air Force confirms that the new target launch time is 7:30 p.m. EST (0030 GMT). The available window extends to 8:48 p.m. EST.

2100 GMT (4:00 p.m. EST)

Final launch pad clearing of personnel should be getting underway soon for this evening's launch. However, the Range is currently "no go" for launch due to the predicted path that the toxic cloud would follow in the event the rocket exploded during the early portion of flight. Computer models are run to determine where the cloud would go based on the winds, temperature and other factors. As a matter of public safety, the toxics prediction must be acceptable in order for the Titan to be cleared for liftoff.

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

Launch pad closeouts continue this afternoon. Officials are now looking at a launch time of about 7:30 p.m. EST, however that has not been confirmed. The available launch window extends until 8:48 p.m. EST.

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

There is still no formal word from Air Force public affairs on the new launch time for today's liftoff of the Titan 4B rocket. However, it would appear that the launch has been pushed back around two hours to approximately 7 p.m. EST.

As the launch pad securing work continues, officials are keeping a close eye on high-altitude winds and the computer models that predict where the toxic cloud from a launch failure would blow. These two constraints are being monitored with keen interest, sources say, because initial checks have revealed iffy conditions this afternoon. There is still a few hours left until launch and officials will hope the conditions will be within limits for liftoff later today.

1815 GMT (1:15 p.m. EST)

Here is a bit more detail about the hydraulic leak that occurred this morning at the launch pad, which delayed rollback of the mobile service tower. Pad engineers tell Spaceflight Now that there was a leak in a hydraulic line leading to one of the brakes on the tower wheels. Hydraulic pressure is needed to release that brake in order for the tower to roll. So the leaky line -- a hose -- was replaced and the tower retraction was able to begin at 12:19 p.m. EST.

1800 GMT (1:00 p.m. EST)

The mobile service tower has been rolled away from the Titan 4B rocket as work continues at Cape Canaveral's Complex 40 for today's launch. Again, the liftoff has been pushed back to around 7 p.m. EST from the planned 4:48 p.m. EST launch time due to delays in completing countdown activities earlier this morning.

Like a building on wheels, the Air Force says the 11.2 million pound mobile service tower is the largest and heaviest self-propelled structure in the world. The 260-foot tall metal cocoon shields the Titan rocket while on the seaside launch pad from the weather while providing access to all areas of the vehicle. Its Class 100,000 cleanroom is where the Milstar satellite underwent final processing after being attached to the rocket.

Over the next couple of hours or so, pad crews will finish chores to lock the tower in its parked position and secure the complex facilities for launch. The loading of the Centaur upper stage with liquid oxygen and liquid hydrogen should get started by around 4:30 p.m. EST.

The weather here at the Cape is showing definite signs of improvement, just as meteorologists predicted. The clouds are beginning to break up and welcomed sunshine is brightening what had been a dark, gloomy day.

1740 GMT (12:40 p.m. EST)

DELAY. It's now official. Today's liftoff will be delayed a couple of hours because countdown activities are running behind schedule at the launch pad. We're still waiting on the official new launch time, but it is expected to be around 7 p.m. EST. Today's launch opportunity ends at 8:48 p.m. EST.

An Air Force spokesperson confirms there was lightning in the area early this morning that forced workers to leave the launch tower for safety reasons, which halted routine pre-flight preparations. Then a hydraulic leak at the pad a few hours ago added to the delay.

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

The mobile service tower is now moving away from the Titan 4B rocket at Cape Canaveral's Launch Complex 40 as the countdown rolls on for this afternoon's liftoff.

The tower rollback was delayed this morning, at least in part, due to a hydraulic leak, officials at the launch pad told Spaceflight Now. The Air Force says rainy weather early this morning also contributed to countdown activities getting behind schedule.

Launch officially remains targeted for 4:48 p.m. EST. However, the liftoff could be easily pushed back into the available four-hour window. The launch team has the luxury of a lengthy window today to get the Titan 4 and its Milstar satellite payload off the ground.

1620 GMT (11:20 a.m. EST)

Retraction of the 260-foot tall mobile service tower from around the Titan 4B rocket is being held up this morning due to a hydraulic leak at the launch pad. Technicians are working to clean up the leak, officials at Complex 40 said.

Despite the delay in countdown activities, officials have not yet pushed back the scheduled 4:48 p.m. EST (2148 GMT) launch time. Today's available launch window extends for four hours -- to 8:48 p.m. EST.

1400 GMT (9:00 a.m. EST)

The early stages of the launch countdown are underway this morning at Cape Canaveral Air Force Station in Florida as clocks tick down to the scheduled 4:48 p.m. EST liftoff of the Titan 4B rocket.

The sky is clouded over and rain has fallen throughout the night here in Central Florida. But the forecast calls for this system to clear out of the area later today. Officially, there is a 60 percent chance of acceptable launch weather during today's four-hour window of opportunity to get the Titan airborne.

At Complex 40 work has started in preparation to roll the mobile service structure away from the rocket, which is a key milestone on the road to launch.

We will update this page as the day progresses with the latest news on the countdown.

TUESDAY, JANUARY 15, 2002

The first space launch of 2002 remains set to go Tuesday when America's most powerful rocket -- the Lockheed Martin-built Titan 4B -- blasts off from Cape Canaveral carrying a vital Milstar communications satellite for the U.S. government.

Liftoff is scheduled for 4:48 p.m. EST (2148 GMT), the opening of a four-hour launch window. Sunset at the launch site, along Florida's east-central coast, occurs exactly one hour into the window.

Air Force weather forecasters are calling for a 60 percent chance of acceptable conditions. The worries come in the form of clouds and rain. But Launch Weather Officer Johnny Weems says there should be a break in the conditions to permit liftoff at some point during the lengthy window.

This Milstar satellite will complete the system's orbiting network of four spacecraft needed to provide near-global coverage for relaying secure, jam-resistant communications between the various branches of the military and government leaders.

"This is a very important event," Christine Anderson, the director of Military Satellite Communications at the Air Force's Space and Missile Systems Center said Monday about the upcoming launch. "The importance of this particular satellite (to launch) tomorrow is that we will complete world-wide coverage for our constellation."

See our report on this page below from Friday for a Milstar overview and launch preview.

Preparations for this launch began in earnest in August following the last Titan 4 mission from the Cape. Air Force Launch Director Lt. Col. Dave Jones says this has been one of the smoothest launch campaigns for the Titan 4 rocket. In fact, the target liftoff date of January 15 set several months ago has remained unchanged with no delays experienced.

The countdown is scheduled to get underway early Tuesday morning. Launch managers will arrive on station at their consoles a few hours later to oversee retraction of the mammoth mobile service tower from around the Titan 4, which is expected to occur around 10 a.m. EST (1500 GMT).

Once the Complex 40 pad is secured and area cleared of all workers, the Centaur upper stage will be loaded with super-cold liquid oxygen and liquid hydrogen cryogenic propellant. Fueling is slated to start at around 2 p.m. EST (1900 GMT).

A 10-minute planned hold is built into the countdown at T-minus 5 minutes, giving officials the chance to perform final readiness polls to verify there are no problems standing in the way of liftoff. If no issues are identified, the countdown clock will pick up for an on-time launch.

Be sure to watch this page for complete live coverage during Tuesday's final countdown and launch.

MONDAY, JANUARY 14, 2002

Pre-launch preparations continue for the Titan 4B rocket in advance of Tuesday's planned liftoff carrying the Milstar 5 spacecraft. The final readiness reviews are scheduled for today to clear the rocket for flight.

The weather forecast has become less optimistic than it was last week. There is now a 60 percent chance weather will permit launch during Tuesday's window of 4:48 to 8:48 p.m. EST, with clouds and precipitation the main threats.

"A disturbance forming in the Gulf of Mexico along a stationary frontal boundary is expected to bring increased cloudiness, warming temperatures, increased winds, and chance of showers today ending by midday Tuesday. Development of this system is somewhat erratic (satellite indicates heaviest cloudiness and rainfall from Central Florida northward); thus there is a chance of adverse weather extending into the countdown period. Temperatures will dip again after passage late Tuesday but not to the levels of last week. Timing of the system's passage across the peninsula is the critical factor. The main concerns for Tuesday are cloudiness and precipitation. Conditions remain favorable for both Wednesday and Thursday with minimal concerns for low-level cloudiness," Launch Weather Officer Johnny Weems said in his forecast this morning.

The launch time forecast calls for scattered low-level clouds at 3,000 feet with 3-to-4/8ths sky coverage and tops at 5,000 feet, scattered-to-broken mid-level clouds at 14,000 feet with 4-to-5/8ths sky coverage and tops at 18,000 feet, broken high-level clouds at 26,000 feet with 3-to-4/8ths sky coverage and tops at 29,000 feet, visibility of 7 miles, westerly winds from 270 degrees, slowly shifting to a northwesterly direction of 330 degrees, at 15 to 20 knots, a temperature of 66 degrees F, relative humidity of 80 percent and showers in the area.

Should the launch slip to Wednesday or Thursday for some reason, the forecast calls for a 90 percent chance of good weather both days with only low-level clouds a concern.

We will update this page following the pre-launch news conference, which is scheduled for 3:45 p.m. EST.

FRIDAY, JANUARY 11, 2002

The U.S. Air Force and Lockheed Martin are preparing to launch the next in a series of satellites that serve as sophisticated communications switching stations in space, relaying vital information between the government authorities and military forces around the globe.

The $800 million Milstar 2-F3 spacecraft, the fifth Military Strategic and Tactical Relay satellite built by Lockheed Martin, is awaiting launch Tuesday by a $450 million Titan 4B rocket from Complex 40 at Cape Canaveral Air Force Station in Florida. A four-hour launch window opens at 4:48 p.m. EST (2148 GMT).

The extended weather forecast for Tuesday calls for generally favorable conditions with an 80 percent chance of meeting the launch rules. The two areas of concern will be clouds and precipitation aloft.

"Another weak cold front is expected to pass through the local area during the weekend producing a slight chance of brief showers. Numerical guidance suggests a disturbance forming in the Gulf of Mexico by Sunday which could also produce a chance of showers on Monday. Temperatures will dip again after passage on Monday but not to the levels experienced the past few days. Constraint concerns for Tuesday would be lingering cloudiness and isolated showers," Launch Weather Officer Johnny Weems reported Thursday.

The launch time forecast indicates scattered low-level clouds at 3,000 feet with 3-to-4/8ths sky coverage and tops at 5,000 feet, visibility of 7 miles, northwesterly winds from 310 degrees at 15 to 20 knots, a temperature of 54 degrees F, relative humidity of 80 percent and isolated showers in the area.

Should the launch slip to Wednesday or Thursday for some reason, the forecast calls for a 90 percent chance of good weather both days with only low-level clouds a concern.

The Lockheed Martin Titan 4 and its liquid-fueled Centaur upper stage will deliver the 10,000-pound satellite into geostationary orbit 22,300 miles above the planet during a six-and-a-half hour mission. At such an altitude, the spacecraft will match the Earth's rotation and appear parked above a spot along the equator.

Although that specific operational point has not been disclosed, program officials say that the satellite will bring "significant tactical communications capabilities to our forces deployed in the European theater."

Trumpeted as the U.S. military's most technologically advanced telecommunications satellite, Milstar acts as a smart switchboard in space, allowing users on foot, ships, submarines or aircraft to establish critical communications networks on the fly. The communications are secure, jam-resistant and have a low probability of being intercepted.

This new satellite will join three others operating in space as part of the Milstar constellation providing protected, global communication links for the joint forces of the U.S. military and can transmit voice, data, and imagery, in addition to offering video teleconferencing capabilities.

One earlier satellite, Milstar 3, was placed into a worthlessly low orbit during a failed launch in 1999.

Milstar 5 will increase the constellation's capability to provide near-global coverage for the nation's strategic forces, the Air Force's missile warning assets and operationally deployed military forces.

The satellite is the third to carry the Medium Data Rate (MDR) payload. Built by Boeing Satellite Systems, the MDR payload has 32 channels, which can process data at speeds of 1.5 megabits per second.

The spacecraft also features the Low Data Rate (LDR) payload, built by TRW Space and Electronics. TRW also supplies MDR antennas and a digital processor to Boeing.

"U.S. forces depend on timely, responsive, secure communications," said Kevin Bilger, vice president of Military Space Programs for Lockheed Martin. "With the MDR payload, the Milstar team is providing a substantial increase in capabilities, allowing our military forces to communicate in a secure mode without betraying their locations and with capabilities very resistant to enemy jammers.

"We are extremely proud to lead the Milstar team and look forward to achieving mission success on this critical event."

Once in space, ground controllers will perform extensive testing and checks of the craft before it enters service. The process can take up to four months, officials said.

The sixth and final Milstar satellite is scheduled for launch in November.

For the Titan 4 rocket, America's most powerful unmanned booster, this will be the first of fourth launches planned in 2002. In addition to the two Milstar flights, a pair of classified satellite launches for the U.S. National Reconnaissance Office are on the books -- one from the Cape and the other from Vandenberg Air Force Base in California.

There are two Titan 4 missions scheduled in 2003 -- a missile warning satellite launch from the Cape and a secret NRO flight from Vandenberg. Titan 4 then will be retired in favor of the next-generation Evolved Expendable Launch Vehicles -- the Boeing Delta 4 and Lockheed Martin Atlas 5.

Watch this page on Tuesday for complete live coverage and play-by-play updates on the final countdown and the launch!