Mission Status Center

The astronauts are progressing through the initial checkout of the space shuttle robotic arm.

A gallery of photos of shuttle Atlantis' launch as seen from Kennedy Space Center's press site can be viewed here.

Space shuttle Atlantis and crew have completed NC1 engine firing to adjust the orbital path to the International Space Station. The course correction maneuver changed the shuttle's velocity by 39 feet per second, resulting in a new orbit of 147 by 118 statute miles.

Live television now being received from payload bay cameras aboard shuttle Atlantis. You can watch it in our webcast.

The ascent team of flight controllers led by Bryan Lunney is handing over to the Orbit 2 team and flight director Gary Horlacher to oversee the rest of the astronauts' workday.

CAPCOM astronaut Chris Ferguson in Mission Control just told the crew that there we no ascent debris events of concern based on the quick-look review of launch video.

The protective doors covering the star trackers on the nose of Atlantis are being opened. The devices are used as part of the spacecraft's navigational systems.

The latest version of the NASA Television schedule (Rev. A) can be downloaded here.

Go for on-orbit operations! That's the formal call from Mission Control indicating the shuttle is in good shape following launch and the Atlantis crew can proceed with mission activities.

Over the next few hours, the astronauts will busily begin setting up the onboard computer network, downlinking imagery and data gathered during ascent, as well as powering up the shuttle's 50-foot-long robot arm for a post-launch checkout in preparation for its use in tomorrow's heat shield inspections. The crew will be getting out of their launch and entry spacesuits, stowing away the mission specialists' seats and getting some dinner as well. An eight-hour sleep period begins at 8:28 p.m. EST.

Both 60-foot-long payload bay doors of shuttle Atlantis have been opened and the radiators deployed.

The space shuttle Atlantis roared to life and raced into orbit Monday on a critical mission to deliver 15 tons of equipment and spare parts to the International Space Station, gear needed to protect against failures after the shuttle fleet is retired next year.

Read our full story.

The space shuttle Atlantis roared to life and raced into orbit Monday on a critical mission to deliver 15 tons of equipment and spare parts to the International Space Station, gear needed to protect against failures after the shuttle fleet is retired next year.

Read our full story.

The radiator preparatory steps have been performed and Mission Control has given the astronauts a "go" for payload bay door opening.

The crew continues working through its post-launch checklist. The next big milestones will be opening up the payload bay doors and deploying the Ku-band communications antenna.

NASA officials report at the post-launch news conference that three foam events were seen in the external tank video camera footage. But they occurred after the aerodynamic sensitive time period and aren't a concern.

T+plus 42 minutes. High definition video of the STS-129 launch is available to Spaceflight Now+Plus customers. A full listing of video can be seen here.

If you are not yet a subscriber for our premimum video service, learn more here.

T+plus 39 minutes, 32 seconds. The twin Orbital Maneuvering System engines on the tail of Atlantis have been fired successfully to propel the shuttle the rest of the way to orbit.

T+plus 38 minutes, 28 seconds. Ignition of the OMS engines has been confirmed.

T+plus 37 minutes. Atlantis in the proper orientation for the upcoming 64-second maneuvering burn to raise the orbit toward the International Space Station.

T+plus 29 minutes, 40 seconds. The umbilical doors are closed and latched.

T+plus 28 minutes. The two flapper doors on the belly of Atlantis are being swung closed to shield the umbilicals that had connected to the external fuel tank.

T+plus 25 minutes. Pilot Barry Wilmore will be powering down the main propulsion system.

T+plus 18 minutes. The planned OMS 2 burn will begin at T+plus 38 minutes, 15 seconds.

T+plus 17 minutes. Atlantis is flying into an orbital sunset as crosses Europe.

T+plus 15 minutes, 30 seconds. The three Auxiliary Power Units are being shut down as planned.

T+plus 11 minutes. Mission Control calls it a "perfect" launch and "flawless" ascent by Atlantis.

T+plus 9 minutes, 30 seconds. It was a nominal MECO. A quick boost from the Orbital Maneuvering System engines is not required to reach the planned preliminary sub-orbital trajectory.

T+plus 9 minutes, 15 seconds. Still cameras embedded in Atlantis' umbilical well are taking images of the external tank to document its foam.

T+plus 8 minutes, 47 seconds. The emptied external tank has been jettisoned from the belly of space shuttle Atlantis. The tank will fall back into the atmosphere where it will burn up harmlessly.

T+plus 8 minutes, 33 seconds. MECO. Main Engine Cutoff confirmed! Shuttle Atlantis is back in orbit for its mission to haul spares to space for the station.

T+plus 7 minutes, 55 seconds. Atlantis is 700 miles downrange, traveling at 15,000 mph.

T+plus 7 minutes, 40 seconds. The main engines are beginning to throttle down to ensure the shuttle does not experience forces greater than 3 g's as it continues to accelerate prior to engine shutdown.

T+plus 7 minutes. Single engine press 104. The shuttle can reach orbit on the power from a single main engine should two fail at this point. But all three continue to fire properly.

T+plus 6 minutes, 55 seconds. Atlantis is 66 miles in altitude, 500 miles downrange from the launch pad, traveling nearly 11,000 mph.

T+plus 6 minutes, 20 seconds. "Press to MECO." Atlantis can now achieve a safe orbit on two engines. All three remain in good shape.

T+plus 6 minutes. The shuttle has started rolling to a heads-up position to improve communications with the TDRS satellite network.

T+plus 5 minutes, 40 seconds. Atlantis is 67 miles in altitude, 312 miles downrange from the launch pad, traveling nearly 8,000 mph.

T+plus 5 minutes, 20 seconds. "Press to ATO". Atlantis can reach an orbit, albeit a low orbit, on two engines should one shut down now. But all three powerplants are still running just fine.

T+plus 5 minutes. Overseeing today's climb to orbit from the Mission Control Center in Houston will be ascent flight director Bryan Lunney. Seated alongside in Houston in direct radio contact with the shuttle crew is CAPCOM astronaut Chris Ferguson.

T+plus 4 minutes, 35 seconds. Atlantis will be tripling its speed in the next four minutes to reach orbital velocity of 17,500 mph.

T+plus 4 minutes, 25 seconds. Atlantis is 62 miles in altitude, 180 miles downrange from the launch pad, traveling nearly 6,000 mph.

T+plus 4 minutes. Negative return. The shuttle has passed the point where Atlantis could turn around and make an emergency landing at Kennedy Space Center in the event of a main engine problem. Landing sites in France and Spain are now available to Atlantis in the unlikely event an abort occurs during the remainder of today's launch.

T+plus 3 minutes, 40 seconds. Atlantis is 55 miles in altitude, 120 miles downrange from the launch pad, traveling at nearly 5,000 mph.

T+plus 3 minutes, 10 seconds. Atlantis is 46 miles in altitude, 81 miles downrange from the launch pad, traveling at nearly 4,000 mph.

T+plus 3 minutes. The Orbital Maneuvering System engines are burning for an extra kick.

T+plus 2 minutes, 53 seconds. Commander Charlie Hobaugh just received the "Two-engine TAL" call from CAPCOM Chris Ferguson in Mission Control. The call means Atlantis can now reach a Transatlantic Abort Landing site if one main engine fails. However, all three engines continue to burn normally.

T+plus 2 minutes, 20 seconds. Guidance is converging as programmed. Atlantis' engine nozzles are swiveling to steer the ship toward a precise point for main engine cutoff about six minutes from now.

T+plus 2 minutes, 10 seconds. Mission Control confirms a good jettison of the solid rocket boosters has occurred. The spent boosters will parachute into the Atlantic Ocean for retrieval. Atlantis continues its streak toward space on the power generated by the three liquid-fueled main engines.

T+plus 90 seconds. The space shuttle now weighs just half of what it did at liftoff. The solid rocket boosters are burning 11,000 pounds of propellant every second. The main engines are guzzling a half-ton of liquid fuel per second from the external tank.

T+plus 70 seconds. Atlantis' three main engines have revved back up to their 104 percent power setting. And Mission Control has given the "go at throttle up" call.

T+plus 60 seconds. All is looking good one minute into this 11-day voyage of Atlantis.

T+plus 40 seconds. Atlantis' three liquid-fueled main engines are throttling down to their 72 percent power setting to ease the strain on the vehicle during passage through the region of maximum aerodynamic stresses.

T+plus 15 seconds. Atlantis is rolling on course for rendezvous with the space station on Wednesday to deliver nearly 15 tons of spare parts and equipment to the orbiting outpost.

T-minus 10 seconds, go for ignition of the space shuttle main engines, 5, 4, 3, 2, 1 and LIFTOFF! Liftoff of Atlantis on a mission to fortify the future of the International Space Station. And the shuttle has cleared the tower!

T-minus 31 seconds. AUTO SEQUENCE START! The handoff has occurred from the Ground Launch Sequencer to the space shuttle. Atlantis' computers now controlling.

In the next few seconds, the solid rocket booster hydraulic steering system will be started, the orbiter's body flap and speed brake moved to their launch positions, the firing chain armed. Main engine ignition begins at T-minus 6.6 seconds.

T-minus 1 minute. Computers are verifying that the main engines are ready for ignition. Sound suppression water system is armed. The system will activate at T-minus 16 seconds to suppress the sound produced at launch. And the residual hydrogen burn ignitors are armed. They will be fired at T-minus 10 seconds to burn off hydrogen gas from beneath the main engine nozzles.

Shortly, the external tank strut heaters will be turned off; Atlantis will transition to internal power; the liquid oxygen and liquid hydrogen outboard fill and drain valves will be closed; the payload bay vent doors will be positioned for the launch; and the gaseous oxygen vent arm will be verified fully retracted.

Now 90 seconds from launch of Atlantis and its six-man crew.

T-minus 2 minutes. The astronauts are being instructed to close and lock the visors on their launch and entry helmets.

At T-minus 1 minute, 57 seconds the replenishment to the flight load of liquid hydrogen in the external tank will be terminated and tank pressurization will begin.

T-minus 2 minutes, 30 seconds. The external tank liquid oxygen vent valve has been closed and pressurization of the LOX tank has started.

Atlantis' power-producing fuel cells are transferring to internal reactants. The units will begin providing all electricity for the mission beginning at T-50 seconds.

And pilot Barry Wilmore has been asked to clear the caution and warning memory system aboard Atlantis. He will verify no unexpected errors in the system.

In the next few seconds, the gaseous oxygen vent hood will be removed from atop the external tank. Verification that the swing arm is fully retracted will be made by the ground launch sequencer at the T-minus 37 second mark.

T-minus 3 minutes. Orbiter steering check is now complete and the main engine nozzles are in their start positions.

T-minus 3 minutes, 30 seconds. The main engine nozzles now being moved through a computer controlled test pattern to demonstrate their readiness to support guidance control during launch.

T-minus 4 minutes. Activation of the APUs is complete. The three units are up and running normally.

And the final helium purge sequence is underway in the main propulsion system. This procedure readies fuel system valves for engine start. In the next few seconds, the aerosurfaces of Atlantis will be run through a pre-planned mobility test to ensure readiness for launch. This is also a dress rehearsal for flight of the orbiter's hydraulic systems.

T-minus 5 minutes. The "go" has been given for for Auxiliary Power Unit start. Pilot Barry Wilmore is now flipping three switches in Atlantis' cockpit to start each of the three APU's. The units, located in the aft compartment of Atlantis, provide the pressure needed to power the hydraulic systems of the shuttle. The units will be used during the launch and landing phases of the mission for such events as moving the orbiter's aerosurfaces, gimbaling the main engine nozzles and deploying the landing gear.

Over the course of the next minute, the orbiter's heaters will be configured for launch by commander Charlie Hobaugh, the fuel valve heaters on the main engines will be turned off in preparation for engine ignition at T-6.6 seconds and the external tank and solid rocket booster safe and arm devices will be armed.

T-minus 5 minutes, 30 seconds. APU pre-start is complete and the units are ready for activation. The orbiters flight data recorders have gone into the record mode to collect measurements of shuttle systems performance during flight.

T-minus 6 minutes. Pilot Barry Wilmore has been asked by the orbiter test conductor to pre-start the orbiter Auxiliary Power Units. This procedure readies the three APU's for their activation after the countdown passes T-minus 5 minutes.

T-minus 7 minutes, 30 seconds. The Ground Launch Sequencer has started pulling the orbiter access arm away from the crew hatch on the port side of the vehicle. The arm was the passage way for the astronauts to board Atlantis a few hours ago. The arm can be re-extended very quickly should the need arise later in the countdown.

T-minus 8 minutes and counting. Pilot Barry Wilmore has flipped the switches in the cockpit of Atlantis to directly connect the three onboard fuel cells with the essential power buses. Also, the stored program commands have been issued to the orbiter for antenna alignment and management during launch.

T-minus 9 minutes and counting! The Ground Launch Sequencer has been initiated. The computer program is located in a console in the Firing Room of the Complex 39 Launch Control Center. The GLS is the master of events through liftoff. During the last 9 minutes of the countdown, the computer will monitor as many as a thousand different systems and measurements to ensure that they do not fall out of any pre-determine red-line limits. At T-minus 31 seconds, the GLS will hand off to the onboard computers of Atlantis to complete their own automatic sequence of events through the final half minute of the countdown.

Now 10 minutes from blastoff.

One more chance to try our experimental test with live streaming video available on your iPhone. Check it out!

The countdown will resume from the T-minus 9 minute mark at 2:19:10 p.m. EST.

"We really appreciate all the effort thats gone into making this launch attempt possible. We know there's been a lot of people working some long hours and long days," commander Charlie Hobaugh just radioed the launch director.

"We're ready to take an incredible vehicle for a ride to meet up with another incredible vehicle, the International Space Station."

NASA launch director Mike Leinbach has conducted his poll and given approval to resume the countdown for liftoff at 2:28 p.m. EST!

The poll by NASA test director Steve Payne confirms there are no technical issues or constraints standing in the way of launch at 2:28 p.m. EST. The Range also reports "go" on the local weather. And Mission Control says that weather at abort landing sites is acceptable, too.

Six minutes are remaining in this built-in hold. Final readiness polls will be conducted over the next few moments.

Now 20 minutes from Atlantis' launch on an eight-and-a-half minute trek to space. At main engine cutoff, Atlantis will be flying on a suborbital trajectory with a high point of 136 statute miles and low point of 36 statute miles, inclined 51.6 degrees to the equator. A half-hour later, the twin orbital maneuvering engines will be fired for 80 seconds to place the shuttle into a 142 by 98 statute mile orbit.

Powering space shuttle Atlantis throughout its eight-and-a-half minute climb to orbit will be the three main engines built by Pratt & Whitney Rocketdyne. The cryogenic powerplants are fed with liquid hydrogen and liquid oxygen stored in the external fuel tank.

In the engine No. 1 position today is the Block 2-2048 engine now making its 10th launch. It has accumulated 6,154 seconds of total firing time on the previous missions, plus ground testing. STS-95 was its debut flight.

Making its 12th launch is the Block 2-2044 in the engine No. 2 position. This powerplant has 6,138 seconds of firing time including ground tests and launches starting with STS-89.

And Block 2-2058 is engine No. 3 on Atlantis. It has four previous flights, starting with STS-116, and some 3,084 seconds of firing time.

The current weather for launch time remains "go" for today's flight of space shuttle Atlantis.

The reusable solid rocket boosters, built by ATK, provide the primary thrust to propel the space shuttle away from Earth during the initial two minutes of flight. The 11 sections on each booster flying on Atlantis are refurbished hardware. The upper cylinder on the right-hand booster, for example, flew on STS-2 in 1981. In all, the twin boosters flying today have reused segments and pieces that trace back to 60 previous shuttle launches and 11 ground test-firings.

The boosters will parachute into the Atlantic Ocean where a pair of retrieval ships are standing by to recover the rockets and tow them back to shore, beginning again the process to disassemble, refurbish and reuse the hardware in the future.

The official launch window, based on the latest radar tracking of the space station's orbit and subsequent revision from Mission Control, extends from 2:28:10 to 2:32:38 p.m. EST.

At launch, the space station will be flying 220 miles above the South Pacific east of New Zealand. Liftoff at 2:28 p.m. EST is timed to place Atlantis on course to dock with the station Wednesday.

A reminder that if you will be away from your computer but would like to receive launch updates, sign up for our Twitter feed to get text messages on your cellphone. U.S. readers can also sign up from their phone by texting "follow spaceflightnow" to 40404. (Standard text messaging charges apply.)

The Spaceflight Meteorology Group based in Houston, which is the group that handles weather at the shuttle landing sites, confirms conditions are observed and forecast "go" at the Kennedy Space Center for Return to Launch Site (RTLS).

T-minus 9 minutes and holding. Countdown clocks have gone into the planned 45-minute, 10-second built-in hold. Launch is targeted for 2:28:10 p.m. EST. Today's available window to get the shuttle off the ground extends about five minutes.

The Orbiter Closeout Crew is driving away from the pad.

The Main Propulsion System helium system is being reconfigured by pilot Barry Wilmore. Soon the gaseous nitrogen purge to the aft skirts of the solid rocket boosters will be started.

Pilot Barry Wilmore has configured the displays inside Atlantis' cockpit for launch while commander Charlie Hobaugh enabled the abort steering instrumentation.

Now one hour away from liftoff. Mission Control in Houston is loading Atlantis' onboard computers with the proper guidance parameters based on the projected launch time.

T-minus 20 minutes and counting. The countdown has resumed after a 10-minute hold. Clocks will tick down for the next 11 minutes to T-minus 9 minutes where the final planned hold is scheduled to occur. The hold length will be adjusted to synch up with today's preferred launch time of 2:28:10 p.m. EST.

Atlantis' onboard computers are now transitioning to the Major Mode-101 program, the primary ascent software. Also, engineers are dumping the Primary Avionics Software System (PASS) onboard computers. The data that is dumped from each of PASS computers is compared to verify that the proper software is loaded aboard for launch.

The work to seal the shuttle's crew compartment hatch for flight is complete. And the closeout team that assisted the astronauts into Atlantis today is stowing equipment in the White Room before leaving the launch pad now.

"Our engineering team has determined the fuel cell electrical issue is likely a function of the configuration of the lighting in the crew cabin and that there's not going to be any troubleshooting necessary prior to launch," NASA launch commentator George Diller says. "They understand the characteristic that they're seeing on this."

The revised liftoff time is 2:28:10 p.m. EST. That's the moment when Earth's rotation carries the launch pad into the plane of the station's orbit.

T-minus 20 minutes and holding. The countdown has paused for a 10-minute built-in hold. Launch is scheduled for 2:28 p.m. EST.

During this built-in hold, all computer programs in Firing Room 4 of the Complex 39 Launch Control Center will be verified to ensure that the proper programs are available for the countdown; the landing convoy status will be verified and the landing sites will be checked to support an abort landing during launch today; the Inertial Measurement Unit preflight alignment will be verified completed; and preparations are made to transition the orbiter onboard computers to Major Mode 101 upon coming out of the hold. This configures the computer memory to a terminal countdown configuration.

Commander Charlie Hobaugh is pressurizing the gaseous nitrogen system for Atlantis' Orbital Maneuvering System engines and pilot Barry Wilmore activated the gaseous nitrogen supply for the orbiter's Auxiliary Power Units' water spray boilers.

All launch weather rules remain "go" at this time.

The ground pyrotechnic initiator controllers (PICs) are scheduled to be powered up around this time in the countdown. They are used to fire the solid rocket hold-down posts, liquid oxygen and liquid hydrogen tail service mast and external tank vent arm system pyros at liftoff and the space shuttle main engine hydrogen gas burn system prior to engine ignition.

The shuttle's two Master Events Controllers are being tested. They relay the commands from the shuttle's computers to ignite, and then separate the boosters and external tank during launch.

We're trying an experimental test with live streaming video available on your iPhone. Check it out!

Initialization of the Ground Launch Sequencer has been completed. This is the master computer program that will run the final nine minutes of the countdown.

The chance of acceptable weather during today's launch window have improved to 80 percent, up from this morning's 70 percent odds.

The outlook includes some scattered clouds at 3,000 feet, a scattered-to-broken layer at 5,500 feet, good visibility and launch pad winds from the north at 12 peaking to 18 knots.

If the launch should slip, there's a 70 percent chance of good weather on Tuesday and 40 percent on Wednesday.

NASA launch commentator George Diller's update on the fuel cell issue:

"The launch team right now is troubleshooting what appears to be a small amount of noise on the fuel cell H2 pump motor, noise associated with the current on the pump motor, which they believe can be correlated with the crew cabin lighting which is also on the same bus. So right now they are discussing whether or not they want to troubleshoot that further or do they want to wait until they get on orbit. Apparently, this has been seen on one previous mission."

Atlantis' hatch has been closed and locked.

The launch team is discussing some readings from a fuel cell pump motor. Officials are debating whether to perform troubleshooting during the countdown or whether once they shuttle is in orbit.

The orbiter closeout team at the launch pad is shutting Atlantis' crew module hatch for flight.

The pad crew is ready to close up Atlantis' hatch.

T-minus 70 minutes and counting. Countdown clocks continue to tick down to T-minus 20 minutes where the next hold is planned. Activities remain on track for liftoff at 2:28 p.m. EST, weather permitting.

The astronauts are completing a series of radio communication checks with ground controllers.

The latest high definition video of the STS-129 launch preparations is available to Spaceflight Now+Plus customers. A full listing of video can be seen here.

If you are not yet a subscriber for our premimum video service, learn more here.

The final Atlantis astronaut has boarded the shuttle today. Randy Bresnik, mission specialist No. 2 and flight engineer, has now entered the hatch. He will sit in the flight deck center seat, giving an extra set of eyes to aid the commander and pilot watch displays and switches during launch and landing.

The 42-year-old grew up in Santa Monica, California, is a lieutenant colonel in the Marines where he has served as a test pilot with over 4,800 hours in 79 different aircraft.

Read his biography here.

All of the launch weather rules are now green. The low cloud ceiling rule isn't being violated any longer.

Chemist and materials science researcher Leland Melvin has boarded the space shuttle today to be seated in the flight deck's aft-right seat and serve as mission specialist No. 1. The 45-year-old grew up in Lynchburg, Virginia and was an 11th round draft pick for the Detroit Lions. He has flown in space once before on STS-122.

Read his biography here.

Three hours and counting until liftoff time. No significant technical issues are being reported in the countdown, but the cloud cover continues to be watched.

Bobby Satcher, an orthopedic surgeon born in Hampton, Virginia and making his first spaceflight, is taking the center seat on the middeck for ascent. He'll be a spacewalker on this flight as mission specialist No. 4.

Read his biography here.

Barry Wilmore, a captain in the U.S. Navy from Mt. Juliet, Tennessee, will be Atlantis' pilot. He has more than 5,900 hours in tactical jet aircraft including support in Iraq and Bosnia.

This spaceflight rookie is making his way to the flight deck's front-right seat right now.

Read Wilmore's biography here.

Mike Foreman, born in Wadsworth, Ohio, is mission specialist No. 3 and the lead spacewalker for the flight. The 52-year-old retired Navy captain has over 5,000 hours in more than 50 different aircraft.

He will ride into orbit in the middeck's left seat.

Read his biography here.

Shuttle commander Charlie Hobaugh, a 47-year-old Marine colonel born in Bar Harbor, Maine with combat aviation and test piloting as his background, leads this voyage of Atlantis. It will be his third spaceflight to the International Space Station, having been a pilot on STS-104 and -118.

He is the first astronaut to board the shuttle this morning, taking the forward-left seat on the flight deck.

Read Hobaugh's biography here.

After taking a few moments to gaze up at their spacecraft, the astronauts have ascended the tower.

Atlantis' crew has arrived at launch pad 39A. The AstroVan came to a stop on the pad surface near the Fixed Service Structure tower elevator that will take the six-man crew to the 195-foot level to begin boarding the shuttle.

The AstroVan is passing the 52-story Vehicle Assembly Building where Atlantis was attached to its external tank and solid rocket boosters and the adjacent Launch Control Center.

The Press Site is located across the street, and reporters went outside to watch the passing convoy. This is a launch day tradition to say farewell and good luck to the astronaut crews.

A poll of launch team members indicates everything is going well in the countdown from a technical standpoint. The weather remains "no go" due to low cloud ceilings, however.

The crew of commander Charlie Hobaugh, pilot Barry Wilmore and mission specialists Leland Melvin, Randy Bresnik, Mike Foreman and Robert Satcher just emerged from their quarters to board the AstroVan for the ride from the Kennedy Space Center Industrial Area to launch pad 39A on the edge of the Atlantic Ocean.

The astronauts are heading down the hallway from the suitup room to board the elevator that will take them down to the AstroVan.

The Final Inspection Team has wrapped up its work at launch pad 39A.

T-minus 3 hours and counting. The countdown clocks are ticking again after the planned two-and-a-half hour built-in hold. Clocks will proceed to T-minus 20 minutes when the next hold is scheduled. A final hold occurs at the T-minus 9 minute mark to synch up with the 2:28 p.m. EST launch time.

The astronauts -- three veterans and three rookies -- are donning their day-glow orange launch and entry partial pressure spacesuits. After final adjustments and pressure checks, the astronauts will depart the suitup room and take the elevator down to the ground level of the Operations and Checkout Building to board the AstroVan for the trip to launch pad 39A around 10:38 a.m.

Our launch webcast with Miles O'Brien, David Waters and astronaut Leroy Chiao is streaming live on the right-hand side of our page. Among the special guests joining the show today will be legendary astronauts Bob Crippen and Mike Foale.

A check of the current weather conditions shows the launch weather rule for cloud ceilings is being violated. The official forecast for launch time shows a 30 percent chance of the cloud cover prohibiting the shuttle from flying today.

The outlook includes some scattered-to-broken low clouds at 3,000 feet, good visibility, launch pad winds from the north at 10 peaking to 15 knots and a temperature of 76 degrees F.

Over the past hour in the countdown, activities underway have included calibrations of the orbiter's inertial measurement units, powering up Atlantis' navigation systems, the pre-flight alignment of ground station antennas with the launch pad and communications checks with the Eastern Range.

As the countdown to launch enters the final five hours, all systems remain "go" for liftoff of space shuttle Atlantis and six astronauts at 2:28 p.m. EST.

We're trying an experimental test with live streaming video available on your iPhone. Check it out!

The Final Inspection Team is out at the launch pad to scan the vehicle for any ice or debris concerns following fueling operations. The team is responsible for checking the shuttle and launch pad one last time prior to liftoff.

The team is comprised of engineers and safety officials from NASA, United Space Alliance and tank-builder Lockheed Martin. At the conclusion of their two-hour tour-of-duty, the team will have walked up and down the entire fixed service structure and mobile launcher platform.

The team is on the lookout for any abnormal ice or frost build-up on the vehicle and integrity of the external tank foam insulation.

The team uses a portable infrared scanner that gathers temperature measurements on the surface area of the shuttle and can spot leaks. The scanner will be used to obtain temperature data on the external tank, solid rocket boosters, space shuttle orbiter, main engines and launch pad structures. The scanner can also spot leaks of the cryogenic propellants, and due to its ability to detect distinct temperature differences, can spot any dangerous hydrogen fuel that is burning. The team member also is responsible for photo documentation.

The team wears the highly visible day-glow orange coveralls that are anti-static and flame resistant. Each member also has a self-contained emergency breathing unit that holds about 10 minutes of air.

A reminder that if you will be away from your computer but would like to receive occasional countdown updates, sign up for our Twitter feed to get text messages on your cellphone. U.S. readers can also sign up from their phone by texting "follow spaceflightnow" to 40404. (Standard text messaging charges apply.)

With the hazardous tanking operation now completed, the Orbiter Closeout Crew and Final Inspection Team have arrived at the pad to perform their jobs. The closeout crew will ready Atlantis' crew module for the astronauts' ingress in a couple of hours; and the inspection team will give the entire vehicle a check for any ice formation following fueling.

TANK FULL. Liquid oxygen has entered stable replenishment mode, officially completing today's three-hour external tank filling process at 8:00 a.m. EST.

T-minus 3 hours and holding. Clocks have entered a planned two-hour, 30 minute built-in hold. Additional pauses are scheduled at the T-minus 20 and T-minus 9 minute marks, setting up the countdown for launch at 2:28 p.m. EST.

Liquid hydrogen loading to 100 percent has been completed. The tank will be replenished through the rest of the countdown to replace the supercold propellant that naturally boils away.

Now passing the two-and-a-half-hour mark into this morning's fueling operations. No troubles have been reported by NASA during tanking.

The liquid hydrogen tank reached the 98 percent level and began the topping sequence.

No leakage is being seen around the ground umbilical carrier plate on the backside of shuttle Atlantis' external tank as the liquid hydrogen system is topped off. It was during this point on previous shuttle missions in March and June that leaks developed. But a tight system is being reported today.

The official launch window, based on the latest radar tracking of the space station's orbit and subsequent revision from Mission Control, extends from 2:23:10 p.m. to 2:33:11 p.m. EST. The targeted liftoff time occurs in the middle of the window at 2:28:11 p.m. EST. That's the moment when Earth's rotation carries the launch pad into the plane of the station's orbit.

NASA says all is going well 90 minutes into the fueling operations for space shuttle Atlantis.

The cryogenics flow from storage spheres at the pad, through feed lines to the mobile launcher platform, into Atlantis' aft compartment and finally into the external fuel tank.

Liquid hydrogen and liquid oxygen loading have switched to the "fast-fill" mode as fueling of space shuttle Atlantis proceeds via remote control at launch pad 39A.

There are two tanks inside the shuttle's external fuel tank. The liquid oxygen tank occupies the top third of the bullet-shaped tank. It will be filled with 143,000 gallons of liquid oxygen chilled to minus 298 degrees Fahrenheit. The liquid hydrogen tank is contained in the bottom two-thirds of the external tank. It holds 385,000 gallons of liquid hydrogen chilled to minus 423 degrees Fahrenheit.

Liquid oxygen loading has completed chilldown and gone into slow-fill.

In their latest forecast issued this morning, meteorologists are predicting a 70 percent chance of acceptable weather conditions at today's 2:28 p.m. EST launch opportunity.

The outlook includes some scattered low clouds at 4,000 feet, good visibility, launch pad winds from the north at 10 peaking to 15 knots and a temperature of 76 degrees F.

"A low pressure system approximately 600 nautical miles east of Florida will linger for several days. A high pressure ridge is established over the area, and no significant weather is expected in the Kennedy Space Center (KSC) area for the next couple of days. Winds will start from the northwest today and veer to the north-northeast through the day. The only concern for launch is a chance for a low cloud ceiling due to a low-level inversion expected over KSC. Our primary concern for launch is a low cloud ceiling.

"One item to note: The solid rocket booster recovery area will experience 7 to 9 foot seas on launch day due to the low pressure area to the east.

"If the launch is delayed, winds begin to veer to the northeast by Tuesday causing a Shuttle Landing Facility (SLF) crosswind concern, and by Wednesday, coastal showers will begin to impact the KSC area as well. Seas in the SRB recovery area will continue to increase Tuesday and Wednesday, and could be as high as 9 to 11 feet by Wednesday."

The liquid hydrogen loading has transitioned from the chilldown thermal conditioning process to the "slow-fill" mode. This fills a small fraction of the tank, then the loading switches to "fast-fill" mode.

FUELING UNDERWAY. Today's filling of space shuttle Atlantis' external fuel tank started on-time at 5:03 a.m. EST, NASA finally confirms.

NASA says there are no technical issues being worked in the countdown. But the weather outlook for this afternoon's launch window has degraded from the previous 90 percent chance of good conditions to a 70 percent chance. Low clouds are the primary concern.

T-minus 6 hours and counting. The countdown has resumed ticking after a two-hour hold. The next scheduled built-in hold will occur at T-minus 3 hours.

The Mission Management Team gave the "go" to fuel Atlantis for today's launch.

T-minus 11 hours and counting. The countdown has resumed ticking after the half-day planned pause. The next scheduled built-in hold will occur at T-minus 6 hours.

For our Spaceflight Now+Plus users, we have posted a stunning time-lapse of tonight's sunset rollback of the pad service gantry from space shuttle Atlantis. You can watch the video in either standard definition or beautiful high definition.

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Space shuttle Atlantis has been uncovered from the cocoon-like service gantry at launch pad 39A for Monday afternoon's liftoff. Ground technicians will spend the next few hours getting pad equipment configured and secured in preparation for the early morning fueling operation.

The Mission Management Team is scheduled to convene its pre-fueling meeting around 4:30 a.m. to review the status of work, the readiness of shuttle systems and the latest weather forecast.

If all goes according to plan, loading of the external tank with propellant will start at 5:03 a.m. EST. The process should take three hours to complete.

Atlantis' six astronauts spent their past day studying flight plans, going to the beach house, visiting with spouses and checking out the shuttle at the pad.

The crew will be awakened for launch day at 4:30 a.m. They'll have breakfast at 5 a.m. and then undergo final medical exams at 5:30 a.m. Suit up begins a little after 10 a.m. and departure from crew quarters is scheduled for 10:38 a.m. in preparation for blastoff at 2:28 p.m. EST.

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The gantry is clear of the shuttle now as it continues to slowly back away.

As the sun begins to set at the Kennedy Space Center, retraction of the rotating service structure from around shuttle Atlantis has started.

Pad workers are getting ready for rollback of the service gantry to reveal Atlantis for tomorrow's launch. You can watch the tower retraction in our live streaming video.

"After many, many months of hard work, STS-129, Atlantis and her crew are nearly ready to fly. We've had a very clean countdown to date and are currently on schedule with no problems to report," says NASA Test Director Steve Payne.

Liquid hydrogen and liquid oxygen reactants for space shuttle Atlantis' electricity-generating fuel cells have been loaded into storage spheres beneath payload bay as standard work continues at pad 39A for Monday's launch.

The cryogenics are combined by the three onboard fuel cells to produce power and a byproduct of drinking water during the shuttle's mission. Technicians pumped the reactants into small tanks on the orbiter during a multi-hour operation that finished last night. The pad umbilical system used in the loading process was demated and stowed.

Also completed overnight were the final tests of the three main engines.

Countdown clocks entered the lengthy T-minus 11 hour planned hold period at 9 a.m. EST. The built-in hold will last 13 hours and 3 minutes.

Today's chores at launch pad 39A are focusing on functional checks of the orbiter's star trackers, activating the inertial measurement units, thoroughly testing the communications network, loading the last items into the crew module, filling of the launch pad's sound suppression system water tank and installing film in pad cameras.

The giant gantry-like rotating service structure is scheduled for retraction from around Atlantis at 5:30 p.m. EST.

The weather forecast for Monday's 2:28 p.m. EST launch time remains ideal.

"Weather does look very good for launch," shuttle meteorologist Kathy Winters says.

With the shuttle program entering its final year of operation, engineers are readying Atlantis for launch Monday on a three-spacewalk mission to deliver 15 tons of spare parts and equipment to the International Space Station as a hedge against failures when the shuttle is no longer available for service calls.

Read our mission preview story.

The countdown has resumed from the planned hold at T-minus 27 hours. The fuel cell servicing work is the focus for the afternoon and into the evening at launch pad 39A.

Meanwhile, the astronauts were awakened at 4:30 a.m. EST this morning. They underwent medical exams and planned some Shuttle Training Aircraft practice at the Kennedy Space Center landing strip.

"We're one day into Atlantis' countdown and I'm happy to report we're right on the money," shuttle launch director Mike Leinbach says. "We're not tracking any issues with the vehicle, any of the flight elements or ground systems. It's a real clean count so far."

The fuel cell reactant loading is slated to begin at 2 p.m. EST today.

The Mission Management Team gathered this morning for its pre-launch meeting and verified all remains on track for Atlantis to go fly Monday.

"It was a really smooth meeting, done in an hour, really good results, everybody is in good shape," chairman Mike Moses says.

The space shuttle countdown has resumed ticking after the four-hour hold tonight while the pad area was cleared for the Atlas 5 rocket launch attempt. Liftoff of Atlantis remains on schedule for Monday at 2:28 p.m. EST.

Activities planned over the next several hours for shuttle workers include buttoning up launch pad equipment and removing platforms inside the shuttle's crew module, reviewing flight software stored in Atlantis' mass memory units, loading backup software into the general purpose computers and testing navigation systems.

Loading of the liquid hydrogen and liquid oxygen reactants for Atlantis' electricity-generating fuel cells is scheduled for Saturday afternoon.

The Atlas rocket will have to be rolled from its launch pad back to the Vertical Integration Facility in light of this technical issue. That means there would be no launch attempt made tomorrow night, clearing the way for the Eastern Range to transition over to space shuttle support for Monday's planned liftoff of Atlantis.

Exactly how long the Atlas delay will last is not yet known.

The launch of an Atlas 5 rocket on a late-night launch to deploy an international telecommunications satellite that will span the Atlantic was scrubbed due to a technical issue.

It is unclear if another launch attempt will be possible tomorrow night or if the Atlas will be delayed until after the planned Monday liftoff of the space shuttle Atlantis.

The shuttle countdown is holding at T-minus 33 hours. It is scheduled to resume ticking at 3 a.m. EST in order to keep the preparations on track for Monday.

COUNT BEGINS. Countdown clocks at the Kennedy Space Center just began ticking toward Monday's scheduled launch of the space shuttle Atlantis.

The official countdown sequence began at 1 p.m. EST inside Firing Room 4 of the Complex 39 Launch Control Center. Launch team members had gathered for the "call-to-stations" at 12:30 p.m. EST.

"Our teams here at Kennedy Space Center, as well as all the NASA centers around the country, have worked very hard preparing this hardware for flight," NASA Test Director Charlie Blackwell-Thompson said. "We're all looking forward to the mission that lies ahead."

The count began from the T-minus 43 hour mark. But a series of holds are timed throughout the next few days, leading to Monday's targeted liftoff time of 2:28 p.m. EST.

The first hold starts at 11 p.m. tonight when clocks reach T-minus 33 hours. This four-hour stoppage occurs while pad 39A is cleared of all workers due to the nearby launch of the Atlas 5 rocket from Complex 41. If the Atlas launch is scrubbed a day, the shuttle countdown would remain holding and Atlantis' liftoff would slip to Tuesday.

The countdown for space shuttle Atlantis' launch to the International Space Station will begin at 1 p.m. EST today.

"I'm happy to report everything at pad A is going well. Our work continues to progress on schedule as we prepare space shuttle Atlantis for her 31st flight on Monday afternoon," NASA Test Director Charlie Blackwell-Thompson said.

"Our preparations to begin launch countdown are nearly complete, our aft compartment is closed out for flight and our payload bay doors close this morning."

The early weather forecast for Monday's planned 2:28 p.m. EST launch predicts a 90 percent chance of acceptable conditions at the Kennedy Space Center, Air Force meteorologists report.

"A deep low pressure system off the Carolina coast is migrating slowly southward, and a high pressure ridge extends into the Gulf of Mexico. The tight pressure gradient between the low and the ridge will continue to cause gusty winds today at Kennedy Space Center (KSC). The surface low will gradually move eastward over the weekend, relaxing the pressuring gradient and decreasing the winds. By launch day, winds will be from the north-northeast and will not be a concern for launch. Weather is favorable for launch with just a slight chance of a low cloud ceiling due to a low-level inversion over KSC."

The outlook includes just a few clouds at 3,000 feet, good visibility, north-northeasterly winds from 020 degrees at 8 peaking to 12 knots and a temperature of 76 degrees F.

The odds of favorable weather for the backup launch opportunities on Tuesday and Wednesday decrease to 70 and 40 percent, respectively.

"Winds begin to veer to the northeast by Tuesday causing a Shuttle Landing Facility crosswind concern, and by Wednesday, coastal showers will begin to impact the KSC area," forecasters say.

Aiming for a Monday afternoon launch toward the International Space Station, the six astronauts to fly aboard shuttle Atlantis traveled from their Houston training base to the Kennedy Space Center today to begin counting down to blastoff.

The crew flew to the Cape aboard a Gulfstream jet, landing at 12:32 p.m. EST on the same runway Atlantis will use to conclude the spaceflight the day after Thanksgiving.

"Thanks for showing up. We're looking forward to a great mission," commander Charlie Hobaugh told the news media just after arriving.

The crew also includes pilot Barry Wilmore and mission specialists Leland Melvin, Randy Bresnik, Mike Foreman and Robert Satcher.

"We're very bless to be here, as well as just to have the opportunity to fly in space," Melvin added.

After making brief statements to the news media at the runway and posing for a photo opportunity, the crew was bussed away. Upcoming on their schedule over the next few hours, the astronauts plan to visit launch pad 39A and inspect the payload bay of Atlantis before the doors are closed for flight tomorrow.

Bedtime will be 8:30 p.m. EST, as the crew shifts its wake/sleep cycle for the mission. They will be awakened at 4:30 a.m. EST Friday for a day devoted to reviewing flight plans and practice runs using the Shuttle Training Aircraft.

The aircraft has pulled to a stop and now the astronauts are filing off. There to welcome the crew is launch director Mike Leinbach.

Touchdown. The astronauts just landed at the Kennedy Space Center's Shuttle Landing Facility runway.

The crew has crossed the Gulf of Mexico and the west coast of Florida on this 900-mile trip. The astronauts' arrival at the Cape is expected at about 12:30 p.m. EST.

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Two days after launching from Kazakhstan, a new Russian module arrived at the International Space Station on Thursday to give the complex another docking port and a platform for spacewalks and science experiments.

Read our full story.

Meanwhile, the shuttle Atlantis astronauts have departed Ellington Field near the Johnson Space Center in Houston for the plane ride over to the Kennedy Space Center in Florida. Their arrival at the launch site is expected between 12 noon and 12:30 p.m. EST.

The hooks and latches have closed, forming a secure connection of the new Poisk module to the Russian segment of the International Space Station.

The station crew plans to open the hatchway and enter into the module tomorrow morning.

The docking probe on the front of Poisk has retracted and the hooks in the docking port are driving closed.

CONTACT AND CAPTURE. Poisk has arrived at the International Space Station! The outpost has a new multi-purpose module to serve as a docking port for visiting Russian spacecraft, an airlock for spacewalkers and a home to external science experiments.

The automated rendezvous system is working to ensure proper alignment of Poisk with the docking target.

With the addition of Poisk, assembly of the International Space Station will be 84 percent complete with a current mass of 732,197 pounds.

The space station and Poisk are passing into an orbital sunset.

The remaining range is nearing 200 feet.

About 330 feet left to go.

Final approach has been initiated. Poisk is 550 feet away from docking.

Mission Control says everything continues to go well. The stationkeeping period has begun to verify all is in readiness before beginning final approach.

The planned roll maneuver is underway with the module about 660 feet away from Zvezda.

Distance separating the two spacecraft now about 750 feet.

Poisk is about 1,300 feet away from the space station now, about to begin a flyaround maneuver to align with the zenith port of the Zvezda module.

Flight controllers in Moscow and Houston are voicing their "go" status for the upcoming docking by Poisk.

The Mini-Research Module 2, or Poisk, is about two-and-a-half miles away from the International Space Station as today's automated rendezvous proceeds toward docking later this hour.

The space shuttle Atlantis astronauts are packing up and getting ready to leave Houston this morning for the flight over to the Cape. The crew is scheduled to arrive at the Kennedy Space Center around 12 noon EST today to begin the countdown for Monday's launch to the International Space Station.

Meanwhile, the space station's size will grow larger today when the new Russian docking module arrives at the complex. A robotic tug is scheduled to deliver the Mini-Research Module 2, or Poisk, at 10:43 a.m. EST.

Live update on both events will be found on this page.

A Soyuz rocket blasted off from the plains of Kazakhstan Tuesday with the International Space Station's newest addition, a module doubling as a docking port for visiting spacecraft and an airlock for spacewalking astronauts.

Read our full story.

Read our earlier status center coverage.