Five days after ending its mission at the International Space Station, a European logistics carrier plummeted back to Earth over the remote South Pacific Ocean on Saturday, disposing of nearly 2.4 tons of trash and liquid waste in a stream of glowing plasma visible from the orbiting complex.

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Europe's fourth Automated Transfer Vehicle backed away from the International Space Station on Monday, firing thrusters to vacate the outpost's safety bubble and begin positioning itself for a destructive re-entry Saturday.

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The separation burn has been completed. The ATV undocked as the vehicles passed 260 miles over Kazakhstan.

Undocking confirmed! Hooks have opened and the ATV is backing away from the aft port of the Zvezda service module.

A separation maneuver about a minute after physical separation will accelerate the ship's departure at a rate of about 4 meters per second, or about 9 mph.

The space station is in free drift mode for ATV departure.

Controllers in Toulouse report the demerging process is complete, with data buses disconnected between ATV and the space station. The next step is opening hooks connecting the vehicles.

A direct radio communications link has been established between the ATV and space station.

Flight engineers Luca Parmitano and Oleg Kotov are monitoring the departure maneuvers from inside the space station. They have a control panel to issue commands to the ATV if the automated system runs into a problem.

The demerging process has begun, in which power and data connections are broken between the ATV and the space station's Zvezda service module.

The ATV, named for Albert Einstein, will have spent 134 days attached to the space station at the time of undocking. It arrived June 15.

Preparations on schedule for undocking in about 19 minutes.

The ATV's avionics have been switched on in advance of undocking.

The ATV control center in Toulouse is "go" for undocking on-time at 0859 GMT (4:59 a.m. EDT).

In a few minutes, ground controllers will begin activating the ATV for undocking.

After 134 days docked to the International Space Station, Europe's fourth automated supply ship is ready for its final act as a disposable garbage scow, with undocking scheduled for Monday and a fiery plunge back into Earth's atmosphere later this week in view of cameras mounted on-board the orbiting complex.

The fourth Automated Transfer Vehicle, named for Albert Einstein, is scheduled to undock from the space station at 0859 GMT (4:59 a.m. EDT).

We will have live coverage of the event beginning at 0845 GMT (4:45 a.m. EDT).

Space station flight engineers Luca Parmitano and Oleg Kotov closed the hatches between the ATV and the space station's Zvezda service module on Friday, following be depressurization of the vestibule and leak checks between the vehicles.

The ATV's pressurized cargo carrier is packed with trash, and the spacecraft's tanks are filled with liquid waste from the Russian segment's waste water tanks.

About the size of a double-decker bus, the ATV arrived at the space station June 15 after a 10-day transit following liftoff aboard an Ariane 5 rocket.

The ATV delivered seven tons of payload to the space station, including 5,465 pounds of supplies stowed inside the craft's cargo cabin, comprising 209 bags containing 1,400 items, according to the European Space Agency.

The Albert Einstein mission carried 1,896 pounds of propellant to transfer into Zvezda's fuel tanks, plus nearly six tons of propellant to use for maneuvering the space station away from space junk and raise its orbit higher.

ATV 4 also delivered 1,245 pounds of water and 220 pounds of air and pure oxygen to revitalize the station's atmosphere.

The ATV provided its last reboost to the space station's orbit Oct. 24, increasing the station's speed by 1.9 mph and raising the lab's orbit by approximately 1 mile.

"This mission has gone without a hitch and is an excellent performance by the operations team at the control center and our industrial partners that built the machine," said Alberto Novelli, ESA's ATV 4 mission manager.

Engineers at the ATV control center in Toulouse, France, will adjust the spacecraft's orbit after undocking to position the ship beneath the space station for its re-entry at about 1200 GMT (8 a.m. EDT) Saturday over the South Pacific Ocean.

The re-entry of Japan's H-2 Transfer Vehicle in September was similarly timed to occur as the HTV passed below the space station, allowing observations of the re-entry by astronauts and a specially-designed camera on the complex.

"To close the mission with such a delicate but spectacular operation is a fitting end to all the hard work of the people involved," said Jean-Michel Bois, head of the ATV 4 operations team in Toulouse.

Europe's fourth Automated Transfer Vehicle pulled into port at the International Space Station on Saturday, delivering a hefty load of supplies, including rocket fuel, experiments, food and clothing for the lab's six-person crew.

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"I never get tired of this because you always manage to astonish me," said Jean-Jacques Dordain, ESA's director-general.

"This is a collective effort, which shows the reliability of the European partnership," Dordain said. "I think among the partners of the ISS, ESA is a reliable partner for the other partners, who can count on it. And I think that we can build the future through a partnership with the European Space Agency and its member states."

Hooks have closed to create a firm mechanical connection between ATV and the space station.

The docking probe on the Automated Transfer Vehicle is being retracted.

Contact and capture confirmed as the ATV and space station fly over the Pacific Ocean.

The approach has resumed again and all systems are "go" for docking.

Range is now 36 feet as the Automated Transfer Vehicle stops again for the final planned hold point before docking.

Control centers in Houston, Moscow and Toulouse will each give their "go" for docking in the next few minutes.

The ATV is again moving toward the space station, heading for the S41 hold point just 36 feet from the complex.

Resembling an X-wing starfighter from the Star Wars film series, the Edoardo Amaldi spacecraft is now about 62 feet from the space station at the S4 hold point.

Controllers in Toulouse will be polled to affirm their readiness to continue the approach to the space station, and the ATV will point its docking probe toward the cone on the aft end of the outpost's Zvezda service module, aligning the ship for arrival.

This hold should last for about 13 minutes.

The ATV is about to arrive at the S4 hold point. The massive spacecraft, which is the size of a double-decker bus, is looming larger in video views from the space station.

The spacecraft's range to the space station is now about 500 feet. Docking now targeted for 1406:47 GMT (10:06:47 a.m. EDT).

The ATV has resumed its movement toward the space station on the way to the S4 hold point 62 feet from the Zvezda docking point.

Departure from the S3 hold point is expected around 1320 GMT (9:20 a.m. EDT), leading to docking around 1407 GMT (10:07 a.m. EDT), according to information on screens inside the ATV control center in Toulouse.

The Albert Einstein spacecraft has switched from GPS to videometer data. It will use the videometers to illuminate the docking port and laser reflectors one-to-ten times per second.

ATV controllers are updating rendezvous tables on the craft's Monitoring and Safing Unit, which would be used to trigger an automatic abort if a problem occurs in the last phase of the approach.

The ATV control center reports the spacecraft will remain in its current location for an extra 10-to-20 minutes to allow engineers to monitor the ship's navigation data and update guidance parameters before resuming its approach.

The ATV's departure from the S3 hold point is scheduled for 1258 GMT (8:58 a.m. EDT), pending final approval from the control center in Toulouse, France.

Now flying over the night side of planet Earth, the Automated Transfer Vehicle is now visible only via blinking navigation lights in the live video stream from the International Space Station. The ATV is 249 meters, or about 817 feet, from the back of the space station's Zvezda module.

NASA and ESA report the videometer and telegoniometer instruments on the ATV are providing the correct navigation data when comparing it with the relative GPS rendezvous system.

This is a welcome relief for engineers concerned about the status of one of the reflectors mounted on the aft end of the space station's Zvezda service module. Officials worried one of the reflectors, which is required for ATV's approach, was damaged by a stuck antenna during the docking of a Progress cargo craft in April.

The ATV's videometer system has been activated.

Now positioned at a hold point approximately 249 meters, or 817 feet, from the space station, the Automated Transfer Vehicle has arrived at the S3 waypoint in today's rendezvous profile.

The craft will remain at the S3 hold point for about 36 minutes as controllers in Toulouse, France, activate the ATV's videometer and telegoniometer optical and laser sensors, which provide precise range, closing rate, directional and lateral motion data to the ship's flight computers in the final phase of docking.

Controllers in Toulouse will also be polled for a "go" to continue the ATV's approach.

The activation of the ATV's optical and laser sensors will confirm the health of a suspect reflector mounted on the Zvezda service module. The ATV's videometer fires laser pulses to bounce off reflectors on Zvezda, feeding the cargo craft's computer with navigation data for its final approach.

Engineers are concerned a stuck antenna on a Russian Progress freighter may have contacted and damaged one of the reflectors when it docked in late April. If the ATV's videometer instrument cannot lock on to the reflector, the craft could enter a loiter orbit for a few days while officials decide what to do.

Astronauts have a spare reflector they could install on the aft end of Zvezda in the event of a problem.

ESA astronaut Luca Parmitano and Russian cosmonaut Alexander Misurkin have tested their ability to send commands to the ATV in the event of a problem. Parmitano and Misurkin will monitor the approach from a console in the Zvezda service module.

At the ATV's last hold point, engineers activated the ATV's Kurs radar system, a backup Russian docking device to be used if the craft's two primary optical sensors run into problems. Controllers also switched on ATV's external lights at this hold point.

A NASA spokesperson says one of the ATV's four propulsion drive electronics units suffered a systems failure earlier in today's rendezvous. This is not expected to be a problem for today's docking, but if a second unit fails, it will trigger an automatic abort.

The ATV has four control chains for its four main maneuvering engines and 28 reaction control thrusters. The failure of one of the electronics units means the ATV will make a docking with three of the engines and 21 of the thrusters.

Prewritten rules for the ATV mission stipulate the craft and proceed with the rendezvous with three of the four propulsion electronics drive units.

The ATV is now visible in live camera views from the International Space Station, appearing as a bright dot against the darkness of space.

The cargo craft now en route to the S3 hold point about 817 feet behind the space station, where it will arrive at 1222 GMT (8:22 a.m. EDT) after a series of four rendezvous burns to fine-tune its path.

Once the craft is at the S3 point, it will switch from relative GPS to laser-guided navigation for the terminal phase of the approach to the space station.

The ATV departed the S2 hold point at a range of 2.2 miles about 10 minutes ago.

See the docking timeline for more details.

A European resupply spacecraft is on track to dock with the International Space Station on Saturday, using a laser-guided autopilot system to make a precision rendezvous and deliver seven tons of fuel and supplies for the lab's six-person crew.

The Automated Transfer Vehicle will approach the space station with the help of GPS navigation, arriving at a "waypoint" about 24 miles behind the complex at 0938 GMT (5:38 a.m. EDT).

The 20-ton spaceship, named Albert Einstein, will reach a second waypoint about 2.2 miles directly behind the space station at 1111 GMT (7:11 a.m. EDT), pausing there for about 30 minutes to activate its Russian KURS docking system and turn on external lights.

An engine burn will begin the ATV's departure from the S2 waypoint at 1142 GMT (7:42 a.m. EDT), guiding the freighter to the S3 hold point 849 feet behind the space station for another pause in the rendezvous.

During the ATV's hold at the S3 waypoint, engineers at the craft's control center in Toulouse will activate the ship's instruments, which will provide range and closing rate data to the ATV's comptuers in the last phase of the rendezvous.

European Space Agency astronaut Luca Parmitano and Russian cosmonaut Alexander Misurkin will man a control console inside the station's Zvezda service module. The station crew would use the device to command the freighter to retreat, abort, or escape the vicinity of the complex.

Crew intervention becomes feasible when the ATV reaches the S3 hold point about 817 feet behind the station at 1222 GMT (8:22 a.m. EDT).

The craft will press closer to the station using precise navigation data derived from the ship's two videometers.

The videometers, working simultaneously with one in standby mode, fire pulses of laser light toward the station one-to-ten times per second.

Acting as space mirrors, 26 reflectors positioned on the back end of the station's Zvezda service module will beam the laser light back to the sensors on Edoardo Amaldi, creating unique light patterns captured on the ATV's cameras. The craft's advanced computers will use the patterns to autonomously determine its orientation, closing rate and distance from the space station.

Two other instruments known as telegoniometers will serve as watchdogs during the final rendezvous, ready to take over if something went wrong with the primary system.

The telegoniometers, similar to police radar guns, emit laser light at a different wavelength toward the Zvezda reflectors up to 10,000 times per second. The light's travel time between Edoardo Amaldi and the station allow the craft determine its range, while the direction of the station is given by the angles of two built-in mirrors rotating to the aim the laser at its target.

The ATV is also equipped with a Russian Kurs radar docking system as a backup.

Another hold in the approach is programmed at a distance of 62 feet for ATV engineers in Toulouse to review the progress of the rendezvous. Albert Einstein is expected to stop at the S4 hold point at 1322 GMT (9:22 a.m. EDT) and hold there for about 13 minutes.

A final halting of the ATV's rendezvous is planned at the so-called S41 point at 1337 GMT (9:37 a.m. EDT) approximately 36 feet from the back end of the station.

If systems remain ready for docking, the 20-ton spacecraft will resume its approach for docking to the Zvezda service module at 1346 GMT (9:46 a.m. EDT).

A Russian Progress cargo ship departed the International Space Station on Tuesday, clearing a docking port for the arrival of Europe's Automated Transfer Vehicle on Saturday.

The Progress M-19M spacecraft undocked at 1358 GMT (9:58 a.m. EDT), backing away from the aft port on the space station's Zvezda service module. Flying on autopilot, the Progress cargo craft fired its engines to distance itself from the complex, and Russian controllers will command the ship to a destructive re-entry over the Pacific Ocean on June 19.

Video cameras on the Progress spacecraft returned live imagery of the space station during the undocking, showing up-close views of the Zvezda docking port and allowing engineers to inspect laser reflectors arranged around the back end of the module.

The reflectors are required for the approach of the ATV, which is set to dock at the same location at 1346 GMT (9:46 a.m. EDT) Saturday.

Engineers were concerned one of the reflectors was damaged when the Progress M-19M freighter docked with the space station April 26. One of the craft's rendezvous antennas failed to deploy after launch, and although the Progress made a successful docking without it, officials worried the stuck antenna may have rubbed against a reflector and caused damage.

Analyses show the antenna, which is made of soft material in the location where it may have struck the reflector, likely caused no damage. But Tuesday's Progress undocking provided the first opportunity for officials to see the location.

The video camera on the Progress only takes low-resolution video, and European Space Agency officials said Tuesday it would be difficult to ascertain the status of the reflector with only the Progress imagery.

Once the ATV arrives at a hold point about 800 feet from the space station, it will activate its laser rendezvous system, allowing engineers to determine whether the reflectors are all working as designed.

If not, the ATV could back away and go into a parking orbit for a few days, giving astronauts time to stage a spacewalk to replace the reflector with a spare.

Since its launch June 5, Europe's 22-ton cargo craft has completed its first orbit correction burns to set up for the ATV's rendezvous with the space station. Later Tuesday, controllers in Toulouse, France, planned to test the ATV's collision avoidance maneuver command, which would be used to guide the craft away from the station in the event of a problem.

Cameras aboard the Ariane 5 rocket recorded dazzling views of the launcher's ascent into space with Europe's fourth cargo freighter bound for the International Space Station, and photographers around French Guiana launch site captured the power and majesty of the heavy-lifter's liftoff Wednesday.

• Check out a video from rocketcams mounted aboard Ariane 5 for its ascent to space.
  
  
• The Ariane 5 rocket painted a colorful spectacle of exhaust in the sky over Kourou. from rocketcams mounted aboard Ariane 5 for its ascent to space.
  
  
• ESA photographer Stephane Corvaja captured up-close views of the launch with remote cameras.

Suspended atop a fiery-hot flow of rocket exhaust, an Ariane 5 launcher lifted off from French Guiana on Wednesday with a bus-sized European-built cargo carrier to deliver fresh food, rocket fuel and experiments to the International Space Station.

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The solar panels aboard the ATV 4 spacecraft have deployed, and the communications antenna has been extended, according to ESA.

"All good news," says ESA director-general Jean-Jacques Dordain.

The ATV's next phase is focused on activating the craft's systems, deploying its four solar panels and extending a communications boom to relay signals between the spacecraft and the International Space Station on final approach

The solar array deployment is due to begin at 2320 GMT (7:20 p.m.) and takes between 5 and 10 minutes to complete.

Communications have been established with ATV.

The Ariane 5 rocket has achieved its 55th consecutive successful launch since 2003 and the vehicle's 65th overall success in 69 flights since 1996.

SPACECRAFT SEPARATION. The Automated Transfer Vehicle just deployed from the upper stage of the Ariane 5 rocket, completing tonight's launch and the start of the trek to the International Space Station for docking June 15.

Plus+60 minutes, 5 seconds. Cutoff confirmed, completed powered flight for the Ariane 5's launch of ATV 4. Standing by for separation of the spacecraft from the launch vehicle.

Plus+59 minutes, 35 seconds. Second stage ignition. This burn will last for about 28 seconds.

Plus+58 minutes. Standing by for the second burn by the upper stage for today's launch.

Plus+56 minutes, 20 seconds. Ariane is 261 km in altitude, traveling at a velocity of 7.4 km/sec.

Plus+50 minutes. The Aestus engine will reignite in about 9 minutes for a 28-second firing to circularize the rocket's orbit at an altitude of 161 miles. The target orbital inclination is 51.6 degrees.

Plus+40 minutes. This coast phase in the ascent, lasting 42 minutes in total, is continuing.

Plus+30 minutes. The Ariane 5 rocket has passed out of communications tracking sites in the Atlantic Ocean and in the Azores. Ground stations in Australia and New Zealand, along with NASA's TDRSS satellite network, will monitor the second Ariane 5 upper stage burn and the deployment of the Automated Transfer Vehicle.

A quick shot of the Ariane 5's fiery blastoff is on our Facebook page. Be sure to like us on Facebook!

Plus+17 minutes, 17 seconds. The Aestus engine has turned off after firing for about 8 minutes to place the ATV payload in a temporary parking orbit.

The Ariane is now entering a ballistic phase, in which the rocket will fly over Europe, Asia and Australia before restarting the Aestus engine to circularize its orbit at an altitude of 161 miles. The second upper stage burn is scheduled to start at Plus+59 minutes, 23 seconds, or 2251 GMT (6:51 p.m. EDT).

Plus+17 minutes. Velocity now 7.55 kilometers per second.

Plus+16 minutes. Altitude is 147 kilometers and velocity is 7.4 kilometers per second.

Plus+14 minutes. The upper stage's first burn will achieve an elliptical parking orbit with a targeted high point of 161 miles and a low point of about 85 miles. A second burn coming up will circularize the orbit.

Plus+11 minutes. Ariane is 146 km in altitude, traveling at a velocity of 7.1 km/sec.

Plus+10 minutes. Altitude is 143 kilometers and velocity is 7.1 kilometers per second.

Plus+9 minutes, 10 seconds. Ariane 5's empty first stage has shut down and jettisoned, and the storable propellant upper stage has ignited for the first of two burns needed to place the ATV in a circular 161-mile-high orbit.

The first stage will fall back to Earth and impact in the Atlantic Ocean west of Portugal.

Plus+8 minutes. Altitude is 136 kilometers and velocity is 5.7 kilometers per second. One minute left in the first stage burn.

Plus+6 minutes. The ATV is headed for a docking to the space station on June 15 at 9:46 a.m. EDT.

Plus+5 minutes. Ariane is 137 km in altitude, traveling at a velocity of 3.1 km/sec.

Plus+3 minutes, 35 seconds. The Ariane 5's payload fairing has jettisoned, exposing the ATV spacecraft now that the rocket is out of the dense atmosphere.

Plus+3 minutes, 10 seconds. Ariane is 97 km in altitude, traveling at a velocity of 2.3 km/sec.

Plus+2 minutes, 24 seconds. The solid rocket boosters have been jettisoned from the Ariane 5 rocket's core stage. The liquid-fueled Vulcain main engine continues to fire to propel the vehicle and its satellite payload to space.

Plus+90 seconds. Burning more than 5 metric tons of fuel per second, Ariane is soaring into the sky bound for the International Space Station.

Plus+60 seconds. The Ariane 5 has roared away from the South American jungle launch site in Kourou, French Guiana. The combined power generated by the twin solid rocket boosters and liquid-fueled main stage engine are propelling this heavy Ariane payload into the twilight sky. The rocket has gone transonic and is nearing the region of maximum aerodynamic pressure.

LIFTOFF! Liftoff of the Ariane 5 rocket with the Albert Einstein spacecraft, Europe's fourth resupply ship for the International Space Station.

H-0. Main engine ignition!

Minus-40 seconds. Ariane 5 is running on internal power.

Minus-1 minute. A fast-paced series of events leading to launch will begin at Minus-37 seconds when the automated ignition sequence is started. The water suppression system at the launch pad will start at Minus-30 seconds. At Minus-22 seconds, overall control will be given to the onboard computer. The Vulcain main engine will be readied for ignition with hydrogen chilldown starting at Minus-18 seconds.

The residual hydrogen burn flares will fire beneath the Vulcain engine at Minus-6 seconds to burn away any free hydrogen gas. At Minus-3 seconds, onboard systems take over and the two inertial guidance systems go to flight mode. Vulcain main engine ignition occurs at Minus-0 seconds with checkout between Plus+4 and 7 seconds. If there are no problems found, the solid rocket boosters are ignited at Plus+7.0 seconds for liftoff at Plus+7.3 seconds.

Minus-2 minutes. The Vulcain main engine supply valves are being opened. And the ground valves for engine chilldown are being closed.

Minus-3 minutes. The scheduled launch time has been loaded into the rocket's main computer system. The main stage tank pressures should now be at flight level.

Minus-4 minutes. Pressurization is now underway for the main cryogenic stage's liquid oxygen and hydrogen tanks. Also, final pyrotechnic arming is starting.

Minus-5 minutes. All status panel lights remain green, indicating no problems right now that could prevent an on-time blastoff.

Minus-6 minutes. Liquid hydrogen and liquid oxygen supplies of the main cryogenic stage are being verified at flight level. Also, the pyrotechnic line safety barriers are being armed.

Minus-7 minutes. The Synchronized Sequence has started. Computers are now in control of this automated final phase of the launch countdown to prepare the rocket and ground systems for liftoff. There are three computers running the countdown -- one aboard the Ariane 5 and two redundant computers at the launch complex.

Minus-8 minutes. The synchronized countdown sequence begins in one minute, transferring all control over to computers.

Minus-10 minutes. Tonight's launch opportunity is just an instant in time. Unlike most Ariane flights that feature launch windows that can extend as much as a couple of hours, this ATV mission has just one second for the rocket to blast off.

Minus-14 minutes. Right now, all systems are "go" for launch. The status panel in the control center remains green.

Minus-18 minutes. At the time of launch, the International Space Station will be flying 258 statute miles over northwestern Ukraine.

Minus-21 minutes. The Synchronized Sequence is being prepped for activation. This computer-run sequence assumes control of the countdown at the Minus-7 minute mark to perform the final tasks to place the rocket and pad systems in launch configuration.

At Minus-4 seconds, the rocket's onboard computer will take over control of main engine start, health checks of the powerplant and solid rocket booster ignition commanding for liftoff.

Minus-25 minutes. Some official numbers from NASA on the ATV cargo load:

• 5465 lbs. of dry cargo
• 1896 lbs. of propellant for transfer to the Service Module
• 5688 lbs. of propulsive propellant
• 1257 lbs. of water
• 220 lbs. of oxygen and air

Total of 14,526 lbs. of cargo, or 7.3 tons

Minus-30 minutes. Although the launch time is being advertised as 2152:11 GMT (5:52:11 p.m. EDT), liftoff will actually occur seven seconds later. The countdown is timed for the moment of ignition of the Ariane 5's first stage Vulcain engine. The 16-story rocket will rise from the pad seven seconds later when the twin solid rocket boosters fire.

The Automated Transfer Vehicle, christened Albert Einstein, will be deployed 64 minutes later.

Live video coverage of the Ariane 5 countdown and launch is beginning.

Minus-60 minutes. Today's launch will be:

• 213th Ariane rocket launch since 1979
• 69th Ariane 5 launch since 1996
• 4th Ariane 5 ES launch since 2008
• 4th ATV launched by Ariane 5
• 137th mission launched toward ISS
• 3rd launch from Guiana Space Center in 2013
• 2nd Ariane 5 launch in 2013

Super-cold liquid oxygen and liquid hydrogen is being pumped into the Ariane 5's core stage now. The first stage's Vulcain 2 engine will consume the propellant during a 9-minute burn.

The weather in French Guiana continues to look favorable for launch, with partly sunny skies and balmy temperatures at the tropical spaceport.

Live streaming video of the launch begins at 2115 GMT (5:15 p.m. EDT).

The launch countdown is underway in French Guiana, with clocks inside the Jupiter control center ticking down toward a precise instantaneous launch time of 2152:11 GMT (5:52:11 p.m. EDT; 6:52:11 p.m. French Guiana time).

The countdown is now at T-minus 9 hours, 40 minutes.

We are reporting live from the Guiana Space Center today on the launch of Europe's Automated Transfer Vehicle on a cargo resupply trip to the International Space Station.

All parameters are currently reported green on the board in the Jupiter control center. Meteorologists expect intermittent rain showers throughout the day, but the official forecast calls for "go" conditions at the time of launch just after sunset this evening.

Fueling of the Ariane 5 rocket's core stage with 385,000 pounds of cryogenic liquid oxygen and liquid hydrogen will begin shortly after 1700 GMT (1 p.m. EDT; 2 p.m. French Guiana time).

Engineers transferred a 173-foot-tall Ariane 5 ES rocket across coastal grasslands at the Guiana Space Center on Tuesday, positioning the booster atop its launch pad for liftoff on a resupply flight to the International Space Station.

With twin solid rocket boosters and a hydrogen-fueled engine firing, the Ariane 5 ES rocket will launch from the European-run spaceport at 2152:11 GMT (5:52:11 p.m. EDT; 6:52:11 p.m. local time).

Check out photos of the rollout and the Ariane 5 rocket on the pad at sunset.

Engineers connected the launcher to the pad's electrical and fluid lines, and a reservoir on the Ariane 5 first stage was filled with liquid helium.

The launch will use the Ariane 5 ES version, which includes a Vulcain 2 main engine, two solid rocket boosters and a hydrazine-fueled Aestus upper stage engine. Ariane 5's most prolific configuration - the Ariane 5 ECA - is used to launch commercial satellites and interplanetary probes with a hydrogen-fueled upper stage engine.

The final countdown will begin Wednesday at 1022 GMT (6:22 a.m. EDT), and a check of the launcher's electrical systems is scheduled for 1422 GMT (10:22 a.m. EDT), followed by configuring the rocket's core stage and Vulcain 2 engine for fueling.

The flight program will be loaded into the Ariane 5's on-board computer about six hours before liftoff, along with alignment of the rocket's navigation system. At this point in the countdown, the launch team, stationed about 3 kilometers from the pad, will also verify radio links between the vehicle and the launch base.

The final workers will evacuate the ELA-3 launch pad by about 1652 GMT (12:52 p.m. EDT) as launch managers receive a weather briefing on the status of high-altitude winds and other conditions before the start of fueling, which begins at about 1714 GMT (1:14 p.m. EDT) with chilldown and filling of the Ariane 5's core stage with liquid hydrogen and liquid oxygen propellants.

The Ariane 5's two strap-on boosters burn solid fuel, and storable hypergolic propellants were loaded aboard the launcher's upper stage in late May.

The Automated Transfer Vehicle will be switched to its internal battery power source at 2141 GMT (5:41 p.m. EDT).

Computers will assume control of the countdown 7 minutes before liftoff at 2145 GMT (5:45 p.m. EDT), managing a fast-paced series of events to pressurize the rocket's propellant tanks, switch the launcher to on-board power, arm its destruct system, and ignite its Vulcain 2 main engine.

Europe's fourth Automated Transfer Vehicle, a massive refueling tanker, cargo transporter and garbage truck rolled into one, is on a tropical launch pad in South America awaiting blastoff toward the International Space Station on Wednesday.

The 44,610-pound unmanned resupply freighter, with the approximate length and diameter of a London double-decker bus, is poised for launch atop an Ariane 5 ES rocket at 2152:11 GMT (5:52:11 p.m. EDT) from the European-run Guiana Space Center on South America's northeast coastline.

Flying northeast from the jungle spaceport, the 856-ton Ariane 5 launcher will empty the casings of its twin solid rocket boosters in a little more than 2 minutes and drain 385,000 pounds of cryogenic liquid hydrogen and liquid hydrogen from its main stage in about 9 minutes.

A hydrazine-fueled upper stage, powered by an Aestus engine, will fire two times to inject the ATV payload into low Earth orbit.

Read our full story.

Launch officials on Monday directed engineers to proceed with final preparations for Wednesday's launch of Europe's next Automated Transfer Vehicle, a refueling tanker and cargo carrier for the International Space Station.

Liftoff is of the ATV atop an Ariane 5 ES rocket is set for 2152:11 GMT (5:52:11 p.m. EDT) from the ELA-3 launch pad at the Guiana Space Center, a spaceport on the northeast coast of South America. Launch will occur just after sunset at the space base, which lies near the sleepy seaside town of Kourou, French Guiana.

Managers with Arianespace, the European Space Agency, and CNES - the French space agency responsible for the space center - convened Monday for the traditional launch readiness review.

The officials gave the "go" for rollout of the 173-foot-tall rocket, which should begin around 1400 GMT (10 a.m. EDT; 11 a.m. local time) with first motion from the Ariane final assembly building.

Riding dual rail tracks, the Ariane 5 launcher and its mobile launch table will be towed by a Titan tug/tractor with a 540-horsepower engine and a special transmission designed to simultaneously allow the truck to run at full power and precisely control its direction and speed.

The journey from the final assembly building to the Ariane 5's ELA-3 launch pad is about 2.8 kilometers, or 1.7 miles.

Europe's next Automated Transfer Vehicle, set for launch in June to the International Space Station, was hoisted atop an Ariane 5 launcher in French Guiana on Friday.

The robotic spacecraft's tanks are filled with propellant, water, air and pure oxygen. Technicians will load the ATV's cargo module with fresh food and other last-minute items over the next week before the Ariane 5's 17.7-foot-diameter payload fairing is added to enshroud the resupply freighter.

Christened Albert Einstein, the cargo craft is Europe's fourth Automated Transfer Vehicle. When it blasts off June 5, the freighter will be the heaviest spacecraft ever launched by Europe - weighing in at an estimated 44,610 pounds, according to the European Space Agency.

It is also the largest vehicle to visit the space station since the retirement of the space shuttle. The ATV measures 32 feet long and 15 feet wide, and its four solar panels, arranged in a distinctive X-shaped patten, stretch out 73 feet tip-to-tip when extended in space.

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