BY JUSTIN RAY

Follow the countdown and launch of the Lockheed Martin Atlas 2A rocket carrying NASA's Tracking and Data Relay Satellite-J. Reload this page for the very latest on the mission. Use our text only page for faster downloads.

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THURSDAY, DECEMBER 5, 2002

Blasted into orbit Wednesday by Lockheed Martin's final Atlas 2A booster, an advanced replacement satellite is en route to join NASA's flotilla of communications spacecraft designed to relay Hubble's dazzling views of the cosmos, link astronauts and mission control and track launching rockets. Read our full launch story.

0440 GMT (11:40 p.m. EST Wed.)

The orbit data has been released by International Launch Services, the firm that markets the Atlas rocket for builder Lockheed Martin.

The Atlas 2A rocket placed TDRS-J into a geosynchronous transfer orbit with a high point of 17,031 nautical miles, well above the minimum required altitude of 13,725 nautical miles. The perigee, or low point of the orbit, is 120.0 nautical miles as targeted. The inclination is 27.0 degrees to the equator, which was also the pre-launch plan.

The launch used the Minimum Residual Shutdown option, allowing the Centaur upper stage to fire until it consumed all of its propellants. That resulted in the apogee being well above the minimum and predicted altitudes and assuring additional satellite lifetime.

0407 GMT (11:07 p.m. EST Wed.)

Boeing controllers made initial contact with TDRS-J at 10:41 p.m. EST as the spacecraft passed over NASA's ground station in Canberra, Australia.

"We couldn't be more pleased with this evening's launch," said Robert Jenkens Jr., TDRS Project Manager at NASA Goddard Space Flight Center. "Controllers have already made contact with TDRS-J and all seems well. My congratulations to everyone who helped make this launch a success."

During the next eight days, a series of orbit raising maneuvers will boost the 7,039-pound satellite into a geosynchronous orbit 22,300 miles above the Earth's equator.

0320 GMT (10:20 p.m. EST Wed.)

The first opportunity for ground controllers to contact the TDRS-J spacecraft will occur at about an hour after liftoff through the Canberra Deep Space Network station in Australia. That communications period should allow engineers the chance to determine the satellite's overall state of health check.

Other activities will include pressurizing the propulsion system, enabling battery charging and unfurling the craft's two 15-foot antenna reflectors. There are 10 retention straps that are released so the lightweight structures can spring into shape. They are folded up like taco shells for launch.

0311 GMT (10:11 p.m. EST Wed.)

T+plus 29 minutes, 43 seconds. SPACECRAFT SEPARATION! The Tracking and Data Relay Satellite-J, the third and final in a series of advance replacement craft for NASA's primary space-based communications network, has been released from the Centaur upper stage following launch by the Lockheed Martin Atlas 2A rocket. This marks the 63rd consecutive successful launch by an Atlas rocket dating back to 1993.

0310 GMT (10:10 p.m. EST Wed.)

T+plus 28 minutes, 30 seconds. Spinup of the Centaur upper stage has started in advance of payload deployment in about a minute.

0310 GMT (10:10 p.m. EST Wed.)

T+plus 28 minutes. The upper stage is now maneuvering to the deployment attitude.

0309 GMT (10:09 p.m. EST Wed.)

T+plus 27 minutes, 10 seconds. This second burn of Centaur lasted until all the propellant was used up. Liquid oxygen ran out first, triggering engine cutoff. The minimum residual shutdown allows the payload to be placed into the highest orbit possible.

0308 GMT (10:08 p.m. EST Wed.)

T+plus 26 minutes, 55 seconds. MECO 2. Centaur has completed its second firing, completing the powered phase of tonight's launch.

0307 GMT (10:07 p.m. EST Wed.)

T+plus 25 minutes, 5 seconds. Engine operating pressures reported normal. This is a planned one-minute, 40-second firing to accelerate the TDRS-J payload into its required orbit around Earth.

0306 GMT (10:06 p.m. EST Wed.)

T+plus 24 minutes, 35 seconds. Centaur has reignited and the engines are at full thrust.

0304 GMT (10:04 p.m. EST Wed.)

T+plus 22 minutes, 30 seconds. Approximately two minutes until Centaur restart. The vehicle is now approaching the African Ivory Coast as it coasts above the Central Atlantic.

0302 GMT (10:02 p.m. EST Wed.)

T+plus 20 minutes. NASA Launch Manager Chuck Dovale reports the flight has gone well so far, no concerns noted to this point in the flight. But still another burn of the Centaur is left to go before TDRS-J is deployed.

0259 GMT (9:59 p.m. EST Wed.)

T+plus 17 minutes. Not much happening at this point in the flight. Centaur remains stable and performing the activities to condition itself for the upcoming second burn.

0256 GMT (9:56 p.m. EST Wed.)

T+plus 14 minutes. Engineers in the Cape Canaveral telemetry lab are receiving the data from the rocket via NASA's Tracking and Data Relay Satellite System. The newest TDRS spacecraft is about 15 minutes away from its deployment into orbit by the Centaur upper stage.

0254 GMT (9:54 p.m. EST Wed.)

T+plus 12 minutes, 10 seconds. Lockheed Martin reports the parking orbit achieved is precisely what was targeted. The vehicle remains in the coast period. Restart of the upper stage is expected in about 12 minutes.

0251 GMT (9:51 p.m. EST Wed.)

T+plus 9 minutes, 54 seconds. MECO 1. The Centaur main engines have shut down as planned following the first of two planned firings to deliver the TDRS-J payload into a preliminary parking orbit. Engine cutoff occurred about 7 seconds past nominal, which is acceptable. The vehicle will coast for just under 15 minutes before the Centaur reignites.

0250 GMT (9:50 p.m. EST Wed.)

T+plus 8 minutes, 50 seconds. About one minute left in this first burn of Centaur. The rocket is 890 miles from the launch pad, speeding along at 13,700 mph.

0249 GMT (9:49 p.m. EST Wed.)

T+plus 7 minutes, 50 seconds. Altitude 105 miles, downrange distance 650 miles, speed 11,900 miles per hour.

0249 GMT (9:49 p.m. EST Wed.)

T+plus 7 minutes, 15 seconds. Vehicle is now being tracked by the Antigua downrange station. Engine operating parameters reported normal.

0248 GMT (9:48 p.m. EST Wed.)

T+plus 6 minutes, 50 seconds. Altitude 104 miles, downrange distance 492 miles, speed 10,300 miles per hour.

0248 GMT (9:48 p.m. EST Wed.)

T+plus 6 minutes. Centaur's RL-10 engines continue to burn normally.

0247 GMT (9:47 p.m. EST Wed.)

T+plus 5 minutes, 10 seconds. Full thrust reported on the Centaur's two engines.

0247 GMT (9:47 p.m. EST Wed.)

T+plus 5 minutes. RL-10 prestart activities have been completed, nozzles are deployed. And the two powerplants have ignited.

0246 GMT (9:46 p.m. EST Wed.)

T+plus 4 minutes, 43 seconds. The sustainer engine on Atlas has shut down as planned. And separation of the Atlas stage confirmed.

0246 GMT (9:46 p.m. EST Wed.)

T+plus 4 minutes. Altitude 66 miles, downrange distance 152 miles, speed over 7,000 miles per hour as the sustainer engine continues to burn.

0245 GMT (9:45 p.m. EST Wed.)

T+plus 3 minutes, 44 seconds. The payload fairing has been jettisoned. It is no longer needed to protect TDRS-J satellite during flight through the atmosphere. The vehicle remains right on course, no problems reported in the ascent so far.

0245 GMT (9:45 p.m. EST Wed.)

T+plus 3 minutes. The booster engines have shut down and the booster package -- the bottom section of the rocket -- has been jettisoned. The sustainer engine of the Atlas vehicle still firing.

0244 GMT (9:44 p.m. EST Wed.)

T+plus 2 minutes. About 45 seconds remaining in the booster engine burn.

0243 GMT (9:43 p.m. EST Wed.)

T+plus 60 seconds. The Atlas booster and sustainer engines, burning kerosene fuel and liquid oxygen, continue to fire, giving the rocket the appearance of a fiery comet streaking across the nighttime sky here at the Cape, albeit a cloudy evening.

0242 GMT (9:42 p.m. EST Wed.)

T+plus 30 seconds. Pitch and roll programs are underway to position the Atlas 2A rocket on the proper trajectory. The vehicle is headed eastward from the Florida coastline on a 95.4 degree flight azimuth.

0242 GMT (9:42 p.m. EST Wed.)

LIFTOFF! Liftoff of the Lockheed Martin Atlas 2A rocket making its finale flight with NASA's TDRS-J spacecraft to complete a new fleet of communications relay stations in the sky! And the vehicle has cleared the tower.

0241 GMT (9:41 p.m. EST Wed.)

T-minus 31 seconds. The launch sequence has been activated.

In the next few seconds the liquid hydrogen and liquid oxygen vent valves will be locked and the flight data recorders will be readied. The engine ignition sequence will begin at T-minus 2.4 seconds.

0241 GMT (9:41 p.m. EST Wed.)

T-minus 1 minute. Engines are being verified ready for flight. The final status checks of the propellant and pneumatic systems are upcoming to confirm the Atlas and Centaur stages are "go" for launch.

In the past minute, the inertial navigation unit was launch enabled, liquid hydrogen tanking was secured, fuel tank pressures reported stable and the ignition enable switch was closed.

0240 GMT (9:40 p.m. EST Wed.)

T-minus 2 minutes. Pressurization of the Atlas/Centaur vehicle has started. Tanks now being brought to proper pressure levels for flight. And the vehicle's inadvertent separation destruct safety system has been armed.

Shortly, the Centaur upper stage will go to internal power and the flight termination system will be armed.

0239 GMT (9:39 p.m. EST Wed.)

T-minus 3 minutes. The water system is being readied for activation at launch pad 36A. Water will flood the pad to suppress the sound produced at liftoff and protect the ground support systems.

0238 GMT (9:38 p.m. EST Wed.)

T-minus 4 minutes. The Atlas booster stage and Flight Termination System are switching from ground-supplied power to internal batteries.

0237 GMT (9:37 p.m. EST Wed.)

T-minus 5 minutes and counting! The clocks are running again. We are now inside the final portion of today's countdown for the launch of the Lockheed Martin Atlas 2A rocket with the TDRS-J satellite payload from pad 36A at Cape Canaveral Air Force Station in Florida. Liftoff is set to occur right on time at 9:42 p.m. EST.

0236 GMT (9:36 p.m. EST Wed.)

TDRS-J is on internal power and "go" for launch.

0236 GMT (9:36 p.m. EST Wed.)

Standing by to resume the countdown in one minute for blastoff at 9:42 p.m. EST.

0235 GMT (9:35 p.m. EST Wed.)

Lockheed Martin Launch Director Adrian Laffitte has given his "go" to resume the countdown and proceed to liftoff at 9:42 p.m. EST. Standing by to resume the countdown in two minutes.

0234 GMT (9:34 p.m. EST Wed.)

The Lockheed Martin final readiness poll of the entire launch team was just performed by Launch Conductor Ed Christiansen in the Complex 36 Blockhouse. Everyone reported "go" for launch!

0234 GMT (9:34 p.m. EST Wed.)

The Tracking and Data Relay Satellite-J payload atop the Atlas rocket is switching from ground-fed power to internal batteries for launch.

The spacecraft, built by Lockheed Martin, will join NASA's TDRS constellation to provide communications between Mission Control and space shuttles and the international space station, relay data from orbiting satellites and track launch vehicles, including tonight's mission.

0233 GMT (9:33 p.m. EST Wed.)

The Eastern Range is confirming its "go" for launch.

0232 GMT (9:32 p.m. EST Wed.)

Now 10 minutes away from the scheduled launch time. The final readiness polls of the launch team and managers are coming up momentarily for the "go" to continue the countdown to liftoff.

0230 GMT (9:30 p.m. EST Wed.)

NASA Launch Manager Chuck Dovale has polled the space agency team with everyone reporting "ready" condition. Now 12 minutes to launch.

0228 GMT (9:28 p.m. EST Wed.)

Should a problem force the countdown to be stopped inside the final 5 minutes, here is an explanation of recycle options depending on when the clocks were halted:

From the start of the automatic countdown at T-minus 31 seconds until T-minus 0.7 seconds, the launch conductor will be able to stop the countdown manually. A hold during the automatic sequence between T-minus 31 seconds and T-minus 11.3 seconds will equire a recycle to T-minus 5 minutes. A hold between T-minus 12 seconds and T-minus 9 seconds will require a recycle to T-minus 5 minutes for a minimum of one hour to re-initialize the INU in preparation for reentering the terminal count. A hold after Atlas start tanks are pressurized or Centaur equipment module vent door squibs fire (T-minus 8.65 seconds) and before T-minus 4 seconds will necessitate a launch abort and require a recycle to T-minus 24 hours. A hold after T-minus 4 seconds but prior to T-minus 0.7 seconds will necessitate a launch abort and require a 48 hour recycle.

0223 GMT (9:23 p.m. EST Wed.)

The blockhouse escape tunnel doors are now being sealed.

0222 GMT (9:22 p.m. EST Wed.)

T-minus 5 minutes and holding. The countdown has entered this final planned hold. The pause is scheduled to last 15 minutes. At this point, all appears in readiness for liftoff at 9:42 p.m. EST from pad 36A at Cape Canaveral Air Force Station, Florida.

0217 GMT (9:17 p.m. EST Wed.)

Coming up on the built-in hold in five minutes. The communications loops remain rather quiet at this point in the countdown. Everything continues to progress smoothly for launch of AC-144 and TDRS-J.

0210 GMT (9:10 p.m. EST Wed.)

Launch Weather Officer Jim Sardonia just gave another update. Things are still looking good.

The latest launch time weather forecast is predicting scattered clouds at 6,000 and 24,000 feet, visibility of 7 miles, southeasterly winds from 150 degrees at 5 gusting to 10 knots, relative humidity of 80 percent and a temperature of 72 to 74 degrees F. The overall probability of violating the launch weather rules is 20 percent.

0207 GMT (9:07 p.m. EST Wed.)

T-minus 20 minutes and counting. Countdown clocks are ticking down to the T-minus 5 minute mark where a 15-minute hold will occur. Liftoff still set for 9:42 p.m. EST.

The Atlas first stage liquid oxygen tank has reached flight level, meaning the rocket is now fully fueled for launch. But given the cryogenic nature of the liquid oxygen and liquid hydrogen loaded into the rocket tonight, the supplies naturally boil away and the propellants have to be replenished during the countdown.

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

The Centaur liquid hydrogen is now reported at flight level.

And a little while ago, interrogation checks were performed to verify the rocket's C-band beacon is ready for use to track the vehicle during flight.

0156 GMT (8:56 p.m. EST Wed.)

Topping of the Atlas liquid oxygen tank is starting.

And an inhibited self test of the rocket's Flight Termination System is underway. The FTS would be used to destroy the vehicle in the event of a malfunction during launch.

0153 GMT (8:53 p.m. EST Wed.)

The Atlas liquid oxygen tank has reached the 98 percent level where it is being maintained. Topping to 100 percent will be completed shortly.

0152 GMT (8:52 p.m. EST Wed.)

The Centaur hydrogen tank is now at 97 percent, heading to flight level.

0142 GMT (8:42 p.m. EST Wed.)

Now one hour away from the scheduled launch time. There are no problems being reported by the launch team.

Fueling of the rocket with super-cold rocket fuel is continuing as planned. The Centaur upper stage hydrogen tank is nearing the 30 percent level; the Atlas first stage liquid oxygen tank is at 60 percent; and the Centaur liquid oxygen tank has been filled.

0135 GMT (8:35 p.m. EST Wed.)

The liquid hydrogen chilldown is now complete and the "go" has been given to load the super-chilled fuel into the Centaur upper stage. The cryogenic propellant will be consumed with liquid oxygen by the stage's Pratt & Whitney-made RL-10 engines to propel the TDRS-J satellite into the targeted geosynchronous transfer orbit tonight.

And the Atlas first stage liquid oxygen tank is now at 30 percent.

0131 GMT (8:31 p.m. EST Wed.)

The Atlas liquid oxygen tank is now at the 10 percent level. The rocket's shiny exterior is turning a frosty white as a thin layer of ice forms from the super-cold liquid oxygen.

0122 GMT (8:22 p.m. EDT Wed.)

The Centaur liquid oxygen tank has reached 95 percent full level where it is being maintained. Topping to 100 percent will be completed shortly. As the countdown proceeds, the tank will be replenished to replace the cryogenic liquid oxygen that naturally boils away.

And the "go" has now been given to commence loading of the Atlas first stage liquid oxygen tank.

Also, the final alignment of the Atlas rocket's inertial navigation guidance computer has been completed, and the flight control system final preps are now beginning.

0115 GMT (8:15 p.m. EST Wed.)

The chilldown conditioning of liquid hydrogen propellant lines at pad 36A is now starting. This process is like the one performed on the liquid oxygen side whereby a small amount of the liquid is released from the pad's storage tank to prepare the plumbing for transferring the Minus-423 degree F fuel into the rocket.

Also at this time the door of the Complex 36 Blockhouse is being sealed, protecting the 120-member launch team. The Blockhouse is located a few hundred feet away from the Atlas 2A rocket at pad 36A, and serves as the control center for the countdown to launch.

0112 GMT (8:12 p.m. EST Wed.)

Launch is now 90 minutes away. The Centaur liquid oxygen tank now above the 50 percent mark. There are no technical problems with the Atlas 2A rocket or TDRS-J spacecraft that are standing in the way of launch at 9:42 p.m. EST.

0104 GMT (8:04 p.m. EST Wed.)

The Centaur upper stage's liquid oxygen tank is now 10 percent full in this initial stage of fueling activities tonight.

0059 GMT (7:59 p.m. EST Wed.)

Chilldown conditioning of the liquid oxygen transfer lines at pad 36A has been completed and the launch team is now beginning to fill the Centaur upper stage with its its supply of super-cold cryogenic oxidizer.

The liquid oxygen is chilled to Minus-298 degrees F, and will be consumed by the Centaur's twin RL-10 engines along with liquid hydrogen to be pumped into the stage a little later in the countdown.

The latest launch time weather forecast is predicting scattered clouds at 4,500 feet, broken clouds at 6,000 and overcast conditions at 21,000 feet, visibility of 7 miles, south-to-southeasterly winds from 150 to 170 degrees at 5 gusting to 10 knots, relative humidity of 75 percent and a temperature of 67 to 69 degrees F. The overall probability of violating the launch weather rules is 20 percent due to cumulus clouds.

0047 GMT (7:47 p.m. EST Wed.)

With the danger area around the complex verified clear, the "chilldown" procedure is starting to thermally condition the liquid oxygen fuel lines at pad 36A in advance of loading the Centaur upper stage.

Meanwhile, gaseous helium chilldown of the Centaur engines and pneumatic bottle charge for the stage have started.

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

T-minus 105 minutes and counting. Countdown clocks have picked up as scheduled following the planned hold. There are no significant technical problems to speak of and the weather forecast continues to call for an 80 percent chance of acceptable launch conditions.

The countdown will continue to T-minus 5 minutes where a planned 15-minute built-in hold is scheduled. Launch of the Atlas 2A rocket with TDRS-J is targeted for two hours from now.

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

With the mobile service tower retracted, the technicians at the pad have announced that the complex securing work is now complete. Launch Conductor Ed Christiansen instructed them to clear the area.

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

Lockheed Martin Launch Conductor Ed Christiansen has just polled the launch team for a readiness check in preparation to begin fueling the Atlas rocket once the countdown resumes. No problems were reported. Launch Director Adrian Laffitte then polled the senior management team with no issues announced. Earlier, NASA Launch Manager Chuck Dovale confirmed the space agency was ready.

Meanwhile, the Air Force has confirmed there are no COLAs, or Collision Avoidance periods, that will prohibit liftoff during any portion of tonight's 40-minute launch window.

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

Now half-way through the 30-minute scheduled hold at T-minus 105 minutes. Launch of this 23rd and final Atlas 2A rocket is still set for 9:42 p.m. EST tonight from Cape Canaveral Air Force Station, Florida.

The Atlas 2 family will live on for a few more flights of the Atlas 2AS vehicle that sports strap-on solid rocket boosters. But this is the final Atlas 2 series launch for NASA.

"TDRS-J marks the end of an era with NASA and Lockheed Martin," said Chuck Dovale, the space agency's launch manager. "It is actually the last NASA Atlas 2 that will NASA be flying with Lockheed Martin. We appreciate all the good rides in the past and we look forward to another good ride (this) evening. And we also look forward to a good Atlas 3 and Atlas 5 relationship with Lockheed Martin Astronautics and International Launch Services."

NASA has one more Atlas mission currently on the books -- the 2005 launch of the Mars Reconnaissance Orbiter aboard an Atlas 3.

0012 GMT (7:12 p.m. EST Wed.)

T-minus 105 minutes and holding. The countdown has gone into a planned half-hour built-in hold.

The count has 45 minutes of built-in holds scheduled over the course the evening that will lead to liftoff at 9:42 p.m. EST (0242 GMT). A second and final hold is planned at T-minus 5 minutes for 15 minutes. The holds are designed to give the launch team a window of time to work any problems that could crop up without delaying other pre-flight preparations.

At launch pad 36A, the service structure has been moved away from the rocket.

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

Launch Weather Officer Jim Sardonia has just given another update to managers. The weather still looks favorable.

WEDNESDAY, DECEMBER 4, 2002
2342 GMT (6:42 p.m. EST)

The mobile service tower -- the building on wheels that encloses the Atlas 2A rocket during its pre-launch campaign at pad 36A -- is now beginning to roll away in preparation for tonight's liftoff.

The tower is used to assemble the rocket and hoist the satellite payload atop the vehicle. It gives workers access to all areas of the rocket and provides protection from the weather. The structure is electrically driven on four-wheel assemblies.

After rolling back to the launch position, technicians will secure the tower in place before clearing the pad so the hazardous fueling operations can begin.

Meanwhile, the final alignment of the rocket's Inertial Navigation Unit guidance computer has started following the recent completion of a navigation test.

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

T-minus 150 minutes and counting. "Man stations for Integrated Launch Operations."

As the countdown enters the final three hours and 15 minutes to tonight's liftoff of the Lockheed Martin Atlas-Centaur rocket -- AC-144 -- and NASA's Tracking and Data Relay Satellite-J, the call has been given to the launch team for members to take their positions at Cape Canaveral Air Force Station.

The countdown is being controlled from the Complex 36 Blockhouse where the 120-member launch team has assembled to oversee the activities leading up to liftoff of this Atlas 2A rocket.

At launch pad 36A, access platforms and equipment inside the mobile service tower have been stowed, and technicians are preparing for retraction of the structure from around the rocket in about 15 minutes.

There are two built-in holds, lasting for a total of 45 minutes, scheduled into the countdown at T-minus 105 minutes and T-minus 5 minutes. Liftoff remains set for 9:42 p.m. EST, the opening of a 40-minute launch window.

Launch Weather Officer Jim Sardonia just completed a briefing to officials. There is still an 80 percent chance of meeting the launch weather rules during tonight's window. The only concern is for cumulus clouds developing later tonight. All the rules are currently "go". The weather reconnaissance aircraft will be dispatched later in the count to examine the conditions aloft to give meteorologists another tool in evaluating the overall picture.

2312 GMT (6:12 p.m. EST)

The Lockheed Martin launch team is preparing to start the Integrated Launch Operations in 15 minutes. Liftoff remains scheduled for 9:42 p.m. EST.

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

At last check, all of the launch weather rules are "go" as the countdown proceeds. The launch team is checking off the various preparatory chores in advance of starting the final phase of the count at 6:27 p.m. EST. Currently, the Eastern Range is beginning holdfire checks to ensure safety personnel can stop the launch late in the count if a problem arises.

2200 GMT (5:00 p.m. EST)

The countdown continues here at the Cape for tonight's Atlas rocket launch. NASA is not reporting any problems at this hour.

Despite the scrubbed landing of Endeavour at nearby Kennedy Space Center today, the weather rules for the unmanned rocket are much less strict than NASA's standards to ensure a safe touchdown for the shuttle, which is just a powerless glider. Forecasters are expecting an 80 percent chance of favorable weather conditions to permit the Atlas launch.

2000 GMT (3:00 p.m. EST)

Today's updated launch weather forecast is available here.

1752 GMT (12:52 p.m. EST)

The countdown is now beginning at Cape Canaveral's Launch Complex 36 for today's liftoff of the Lockheed Martin Atlas 2A rocket carrying the TDRS-J communications satellite for NASA. Launch remains scheduled to occur at 9:42 p.m. EST. There are no reports of any problems.

Throughout the day the crews in the blockhouse and at pad 36A will proceed through their standard countdown chores needed to ready the Atlas booster and its Centaur upper stage for launch, as well as the ground systems and TDRS-J spacecraft.

Highlights of activities planned, in the order they are scheduled to be performed, include powering up TDRS-J and establishing RF links, Centaur propulsion launch preps, powering up the rocket's flight control system, Atlas propulsion and hydraulic systems preps, preps of the pad's tower and mobile service structure, performing the flight control operational test, the internal power test of Atlas/Centaur, performing a navigation test of rocket's guidance computer, Centaur engine igniter checks, starting Centaur helium purges and starting liquid hydrogen and liquid oxygen system final preps.

The Integrated Launch Operations -- the final portion of the countdown in which all members of the launch team participate -- will start at 6:27 p.m. EST. Retraction of the mobile service tower from around the rocket is slated for 6:42 p.m. EST.

Countdown clocks will enter a planned 30-minute hold at the T-minus 105 minute mark starting at 7:12 p.m. EST. During this time the launch team will have a chance to catch up on any work that might be running behind schedule.

Fueling operations will commence at 7:56 p.m. EST with super-cold liquid oxygen flowing into the Centaur upper stage. Loading of liquid oxygen into the Atlas booster stage should start at 8:22 p.m. EST. The final segment of fueling will begin at 8:36 p.m. EST when liquid hydrogen is pumped into the Centaur. The Atlas stage has already been fueled with its supply of RP-1 kerosene.

A final planned hold is scheduled at T-minus 5 minutes for 15 minutes in duration. If there are no problems standing in the way of liftoff, the countdown will resume at 9:37 p.m. EDT for an on-time launch.

Watch this page for play-by-play updates on the countdown and launch throughout the evening!

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

The last in the line of Lockheed Martin Atlas 2A rockets will fly tonight, if all goes according to plan, to launch the final satellite in NASA's advanced series of tracking and data relay spacecraft.

Liftoff is scheduled for 9:42 p.m. EST from pad 36A at Cape Canaveral, Florida. The launch window extends to 10:22 p.m. EST.

"We are good to go," NASA launch manager Chuck Dovale said Tuesday afternoon. "We are not tracking any issues for an on-time liftoff."

Countdown clocks are due to begin ticking at 12:52 p.m. EST, kicking off nearly nine hours of activities to power up the rocket and TDRS-J spacecraft, run final tests, retract the mobile service tower and load super-cold liquid hydrogen and liquid oxygen propellants into the vehicle.

The weather forecast calls for a 70 percent chance of meeting the launch rules. However, the percentage could be improved by Launch Weather Officer Jim Sardonia when he issues his launch day forecast. Sardonia was sounding more optimistic on Tuesday afternoon based on the latest weather prediction models.

This will be the fifth and last Atlas launch of 2002 -- a year that saw the successful debut of the next-generation Atlas 5. The year ends with the finale launch of Atlas 2A -- the least powerful version of the Atlas family currently in service. The Atlas 2A has flown 22 times since June 1992 with a perfect mission success record.

Some other statistics for those of you keeping score, this will be the 573rd flight of an Atlas booster, the 159th for a Centaur upper stage (including Atlas and Titan missions), the 123rd Atlas launch for NASA and 11th for the space agency under the commercial Atlas program.

If successful tonight, the consecutive success string of Atlas launch will be extended to 63 dating back to 1993.

Watch this page for countdown updates throughout the evening and live coverage of the 30-minute trip to place TDRS-J into geosynchronous transfer orbit.

TUESDAY, DECEMBER 3, 2002
1630 GMT (11:30 a.m. EST)

Senior officials are holding the final launch readiness reviews today, ensuring everything is set for tomorrow's countdown and flight of the Lockheed Martin Atlas 2A rocket and TDRS-J spacecraft. The pre-launch news conference is set for 3:30 p.m. EST today to give reporters the word that all systems are "go" for liftoff.

We have posted this morning's updated launch weather forecast here.

At launch pad 36A today, workers are scheduled to perform routine installation and connection of ordnance aboard the Atlas-Centaur rocket. A series of tests are also planned including telemetry and radio frequency checks and a navigation test of the rocket's guidance computer.

MONDAY, DECEMBER 2, 2002
1600 GMT (11:00 a.m. EST)

This morning's updated launch weather forecast is available here.

SUNDAY, DECEMBER 1, 2002

The third member in a trio of advanced tracking and data relay spacecraft for NASA heads into orbit this week, joining a satellite constellation that has linked Earth and space for nearly 20 years.

The TDRS-J satellite is scheduled for blastoff at 9:42 p.m. EST Wednesday (0242 GMT Thursday) from launch pad 36A at Cape Canaveral Air Force Station, Florida.

Air Force meteorologists are calling for a 70 percent chance of favorable conditions during the night's 40-minute launch window. See the forecast here.

The final Lockheed Martin Atlas 2A rocket will carry the 7,039-pound spacecraft into a highly elliptical geosynchronous transfer orbit looping from 120 to 16,278 nautical miles and inclined 27 degrees to the equator. Deployment of TDRS-J from the Centaur upper stage is expected 29 minutes, 36 seconds after launch.

Over the following days, the satellite will propel itself into geostationary orbit 22,300 miles above the equator, parking at 150 degrees West longitude to undergo extensive testing.

TDRS is the vital link that allows Mission Control near continuous communications with orbiting space shuttles and the International Space Station, plus relays data from unmanned spacecraft like the Hubble Space Telescope and the Terra and Aqua Earth observers and tracks rockets during flight.

The TDRS system was conceived in the 1970s as a means to close costly ground stations scattered around the globe. The first TDRS satellite was launched by space shuttle Challenger on STS-6 in April 1983. Today, NASA operates a fleet of eight TDRS satellites. One other satellite, TDRS-B, was destroyed in the 1986 Challenger accident.

TDRS-J is the third and last of the next-generation TDRS satellites built by Boeing.

"This spacecraft will join its two immediate predecessors in bringing valuable new capacity and capability to the TDRS fleet, which serves as the primary communications lifeline for mankind's near-Earth exploration efforts in space," said Randy Brinkley, president of Boeing Satellite Systems. "The technology aboard TDRS-J will provide more than twice the current science data transmission rates for future space missions."

Watch this page for pre-launch updates over the next few days and comprehensive live updates throughout Wednesday's countdown.