BY JUSTIN RAY

THURSDAY, JUNE 12, 2008

Serious damage to the "flame trench" at launch pad 39A during the shuttle Discovery's May 31 takeoff will require extensive repairs, officials said today, but engineers believe the work can be completed in time to support the planned Oct. 8 launch of shuttle Atlantis on a long-awaited flight to service the Hubble Space Telescope.

Read our full story.

2030 GMT (4:30 p.m. EDT)

Space shuttle Discovery just completed an orbit adjust burn designed to maximize landing opportunities this weekend at Kennedy Space Center. Using the right Orbital Maneuvering System engine on the tail of Discovery, the brief firing changed the shuttle's speed by about 4 mph. The shuttle's orbit was boosted from 186 by 181 miles to 190 by 181 miles.

1330 GMT (9:30 a.m. EDT)

The Discovery astronauts took the day off Thursday, enjoying the view from 210 miles up and chatting with family members in private teleconferences. The only mission-related activity on the schedule is a rocket firing to adjust the shuttle's orbit slightly to improve landing opportunities at the Kennedy Space Center.

Read our full story.

WEDNESDAY, JUNE 11, 2008

NASA managers are considering a plan for the crew of the next space station assembly mission, scheduled for launch around Nov. 10, to clean up and lubricate a damaged, debris covered solar array drive gear and to replace 12 bearing assemblies in a bid to use the mechanism as long as possible before switching to a backup gear, an official said Wednesday.

Read our full story.

1355 GMT (9:55 a.m. EDT)

Read our undocking story here.

1320 GMT (9:20 a.m. EDT)

The shuttle is quickly departing the immediate vicinity of the space station following separation burn No. 2 at 9:19 a.m. EDT.

The astronauts will spend the rest of today using the Orbiter Boom Sensor System to inspect the shuttle's heat shield. This will be the first full survey of the ship's wing leading edge panels and nose cap using the 50-foot boom during the mission.

1252 GMT (8:52 a.m. EDT)

The shuttle just performed the first of two separation engine firings. Discovery is back out in front of the station to complete a full loop flyaround. Once at a point well above the station, the final burn is scheduled.

1241 GMT (8:41 a.m. EDT)

The shuttle is below the station now. Mission Control says pilot Ken Ham has a steady hand on the stick, using less propellant than budgeted.

1229 GMT (8:29 a.m. EDT)

The shuttle has moved directly behind the station in terms of the direction of travel of the two spacecraft around the Earth, which is known as the -V bar.

1215 GMT (8:15 a.m. EDT)

Discovery is reaching a point about 600 feet directly above the space station.

The flyaround started with the shuttle in front of the station. It takes Discovery to a point directly above the complex, then behind it, looping below and back out in front. After climbing above the station for a second time, the final separation engine firing will be performed. This burn will send Discovery away from the vicinity of the station.

1205 GMT (8:05 a.m. EDT)

Pilot Ken Ham has begun flying Discovery in a one-lap flyaround of the station.

1200 GMT (8:00 a.m. EDT)

Distance separating Discovery and the station has increased to 342 feet.

1154 GMT (7:54 a.m. EDT)

Discovery is now 150 feet from the station. The shuttle is headed to a point a few hundred feet away where it will fire thrusters to begin an arc above the station.

The shuttle was linked up to the station for 8 days, 17 hours and 39 minutes.

1144 GMT (7:44 a.m. EDT)

The undocking is occurring in orbital darkness more than 200 miles above the planet, to the east of Australia.

1142 GMT (7:42 a.m. EDT)

UNDOCKING! Discovery is departing the space station for return to Earth this weekend. This successful mission accomplished three spacewalks and continued construction of the outpost by delivering the Kibo science laboratory and relocated its logistics module, two of three elements that will comprise Japan's portion of the station.

1140 GMT (7:40 a.m. EDT)

The hooks and latches that have held Discovery and the station tightly together for the past 9 days are now driving open.

1139 GMT (7:39 a.m. EDT)

Three minutes from the rescheduled undocking time of 7:42 a.m. The steering jets on Discovery are inhibited for the period of physical undocking from the station. The separation occurs when large springs push the two craft apart. Once the shuttle is a couple feet away from the station and the docking devices are clear of one another, pilot Ken Ham will fire Discovery's thrusters to continue the movement away. Once a few hundred feet out in front of the station, the shuttle will begin a one-lap flyaround of the complex.

1122 GMT (7:22 a.m. EDT)

All remains in readiness for Discovery's departure from the space station about 20 minutes from now.

1100 GMT (7:00 a.m. EDT)

The Discovery astronauts geared up for undocking from the international space station today at 7:42 a.m., leaving astronaut Gregory Chamitoff behind with Expedition 17 commander Sergei Volkov and flight engineer Oleg Kononenko and bringing Garrett Reisman home Saturday after three months in space.

Reisman and his shuttle crewmates were awakened shortly after 4 a.m. by a recording of John Fogerty's "Centerfield" beamed up from mission control for pilot Kenneth Ham.

Read our full story.

TUESDAY, JUNE 10, 2008

The shuttle Discovery's crew bid farewell to space station commander Sergei Volkov, Oleg Kononenko and incoming flight engineer Gregory Chamitoff Tuesday, sharing a few final thoughts, hugs and handshakes before closing hatches and preparing the shuttle for undocking early Wednesday.

Read our full story.

1250 GMT (8:50 a.m. EDT)

The Discovery astronauts are working through a final day of equipment transfers to and from the space station before closing hatches late Tuesday and undocking early Wednesday. Outgoing flight engineer Garrett Reisman, returning to Earth after three months in space, planned to squeeze in a final few hours of handover time, briefing his replacement, Gregory Chamitoff, on the intricacies of life aboard the station.

Read our full story.

MONDAY, JUNE 9, 2008

The powder-like debris dusting the outer edge of the space station's left-side solar array rotary mechanism does not appear to represent a serious problem, spacewalker Mike Fossum said Monday. He said the grease and debris seen on the port solar alpha rotary joint does not look anything like the much more severe contamination that has hobbled the station's right-side SARJ.

Read our full story.

1258 GMT (8:58 a.m. EDT)

The Japanese Kibo science laboratory began stretching out its robotic arm this morning for a full deployment test.

Further joint and brake tests will be performed this morning.

1110 GMT (7:10 a.m. EDT)

The Discovery astronauts plan to exercise the Japanese Kibo module's robot arm today, re-open the Japanese logistics module mounted atop Kibo Friday and replace spacesuit battery chargers in the Quest airlock module.

Read our full story.

SUNDAY, JUNE 8, 2008
2100 GMT (5:00 p.m. EDT)

Read our full story on the end of today's EVA.

2029 GMT (4:29 p.m. EDT)

EVA ENDS. Repressurization of the Quest airlock module began at 4:28 p.m. EDT, marking the official end of this third and final spacewalk by Mike Fossum and Ron Garan during Discovery's STS-124 mission.

The EVA lasted 6 hours and 33 minutes. That brings the total time for the three spacewalks to 20 hours and 32 minutes.

This was the sixth spacewalk in Fossum's space career and the third for Garan.

2015 GMT (4:15 p.m. EDT)

Both spacewalkers have climbed back inside the airlock.

1945 GMT (3:45 p.m. EDT)

Nearing the six-hour mark in this third and final spacewalk of Discovery's mission. The astronauts are completing some bonus work with the time remaining in the EVA, basically lower priority tasks that can be finished relatively quickly.

1910 GMT (3:10 p.m. EDT)

Installation of the port truss TV camera has been successfully accomplished.

1852 GMT (2:52 p.m. EDT)

Garan says he has the camera chore under control, so Fossum is going to tackle a get-ahead task of adjusting some thermal covers on Harmony module umbilicals.

1845 GMT (2:45 p.m. EDT)

Garan has started the installation procedures to mount the newly-repaired TV camera to the station's port truss.

1830 GMT (2:30 p.m. EDT)

While still outside the Kibo module, spacewalker Mike Fossum has tightened a bolt on one of the external television cameras installed on the last EVA. During use yesterday to watch the robot arm's initial deployment, the camera seemed wobbly while panning and tilting.

And in preparation for the next major task of the spacewalk, Ron Garan went back to airlock to retrieve a U.S. television camera for installation onto the Port 1 truss. That camera had a faulty power supply, so the spacewalkers brought it inside the station after the last EVA for repairs.

1755 GMT (1:55 p.m. EDT)

Now four hours into the spacewalk. Fossum is working to remove thermal insulation on wrist and elbow cameras on the Japanese robot arm.

1730 GMT (1:30 p.m. EDT)

Spacewalker Mike Fossum is working on the far end of the Kibo science lab to remove some additional covers on the Japanese robot arm and deploy some protective debris shields around the docking interface between the lab and the logistics module mounted on the roof.

Ron Garan remains at work on the Starboard 1 truss connecting fluid lines associated with the new nitrogen tank.

1700 GMT (1:00 p.m. EDT)

Perched on the end of the space station's fully extended robot arm, astronaut Ron Garan manually carried a 528-pound nitrogen tank from one side of the lab's main power truss to the other today, enjoying a spectacular there-and-back windshield-wiper ride that carried him eight stories above the research station.

Read our full story.

1638 GMT (12:38 p.m. EDT)

Garan has attached electrical connectors to the new nitrogen tank. Now he will button up the worksite to complete this major task of today's EVA.

1623 GMT (12:23 p.m. EDT)

Fossum has used a strip of Kapton tape to obtain a dust sample from the port SARJ of the station, the massive wheel that allows the P4 and P6 solar wings to rotate during each orbit of the Earth. He is now taking some additional closeup pictures of the ring. The port SARJ has been working well, while the starboard side had experienced damage of unknown origin.

1608 GMT (12:08 p.m. EDT)

Mike Fossum has moved a very short distance to the Solar Alpha Rotary Joint on the Port 3 truss where he will remove one cover and use tape to collect a sample of dust he found in the device during an earlier spacewalk on this mission.

Meanwhile, Garan is bolting the new nitrogen tank into the station now.

1555 GMT (11:55 a.m. EDT)

Now two hours into the EVA. Garan has arrived in front of the Starboard 1 truss slot where the nitrogen tank will be inserted.

1551 GMT (11:51 a.m. EDT)

The robotics officer in Mission Control says the Canadarm 2 is stretched to its full 58-foot length in this task of swinging spacewalker Ron Garan and the new nitrogen tank from the port-side to the starboard-side of the space station.

1545 GMT (11:45 a.m. EDT)

Garan is en route to the other side of the space station with the replacement nitrogen tank in hand. So far, so good in today's spacewalk.

1534 GMT (11:34 a.m. EDT)

The old tank has been inserted into the storage box. Some restraint bolts will be engaged, then Garan will grab the new tank and take a reverse "windshield wiper maneuver" above the station to reach the Starboard 1 truss while riding the robot arm.

1524 GMT (11:24 a.m. EDT)

Fossum has removed the fresh nitrogen tank from its stowage container on the station's external spare parts deck attached to the Port 3 truss segment. The new tank has been temporarily anchored to a handrail, allowing the old tank to be deposited into the storage box. Garan will then pick up the replacement and carry it back to the Starboard 1 truss for installation.

1512 GMT (11:12 a.m. EDT)

"Enjoy the ride," robot arm operator Karen Nyberg just advised Garan.

1510 GMT (11:10 a.m. EDT)

With a firm grasp of the 528-pound nitrogen tank in his hands, spacewalker Ron Garan has pulled the old assembly out of the Starboard 1 truss of the space station to carry it over to the port-side of the complex. There he will stow the tank for its eventual return to Earth and pick up a fresh one to install in the S1 truss.

1500 GMT (11:00 a.m. EDT)

Spacewalker Ron Garan, perched on the end of the station's robot arm, is working to release four bolts and electrical connectors on the depleted nitrogen tank for its removal this morning. Mike Fossum, meanwhile, is busy prepping the new tank to slide it out of the stowage box.

1440 GMT (10:40 a.m. EDT)

This is the 112th spacewalk devoted to station assembly and maintenance since construction began in 1998 and the 13th so far this year. Going into today's outing, total station assembly EVA time stood at 700 hours and three minutes while Fossum and Garan have logged 13 hours and 59 minutes outside during spacewalks Tuesday and Thursday.

1420 GMT (10:20 a.m. EDT)

After exiting the Quest airlock module and gathering their tools, Fossum will make his way to External Stowage Platform-3 on the station's port truss to prepare the new nitrogen tank for handoff while Garan proceeds to the starboard side of the truss to pull out the depleted tank.

1356 GMT (9:56 a.m. EDT)

EVA BEGINS. The spacewalkers switched their suits to internal battery power at 9:55 a.m. EDT, marking the official start time for today's EVA by Mike Fossum and Ron Garan.

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

Depressurization has been completed and the Quest airlock's outer hatch leading to space is now open.

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

Both spacewalkers have entered into the airlock for closure of the hatchway and the start of depressurization. EVA preparations are running more than 30 minutes ahead of schedule this morning.

1250 GMT (8:50 a.m. EDT)

Astronauts Mike Fossum and Ron Garan are preparing for a third and final spacewalk today, a six-and-a-half-hour excursion highlighted by a dramatic robot arm ride over the top of the international space station to replace a nitrogen tank. Dubbed the "windshield wiper maneuver," the ride from one side of the station to the other will put Garan "clearly on top of the world," said arm operator Karen Nyberg, as he carries the 550-pound tanks.

Read our full story.

SATURDAY, JUNE 7, 2008
2045 GMT (4:45 p.m. EDT)

The Discovery astronauts unlimbered the Kibo laboratory module's Japanese robot arm today and prepared spacesuits and equipment for a third and final spacewalk Sunday to collect debris samples from a solar array rotary joint and install a tank of pressurized nitrogen for the space station's ammonia coolant loops.

"Preparations for the third walk are going great," said spacewalker Michael Fossum. "We've got the suits checked out and just about ready to go, all our tools packed up and after a few final procedures reviews, we'll be ready to go out the door tomorrow."

Mission managers early today approved a plan for Fossum collect samples of apparent debris he saw inside the station's left-side solar alpha rotary joint during the crew's second spacewalk Thursday.

Read our full story.

1810 GMT (2:10 p.m. EDT)

A trailer previewing our new high-definition videos is available on the Spaceflight Now HD index page. Check it out here.

If you are not yet a subscriber, you can learn how to sign up here.

1800 GMT (2:00 p.m. EDT)

Kibo's robot arm successfully moved for this time today, exercising its electronics and mechanics under the careful eye of astronaut operators Akihiko Hoshide and Karen Nyberg, along with the Japanese mission control center. No problems were reported during the initial flexing. A full deployment and checkout of the arm will occur in the future.

1400 GMT (10:00 a.m. EDT)

The Discovery astronauts plan to slightly unlimber the Kibo laboratory module's Japanese robot arm today and prepare for a third and final spacewalk Sunday to install a tank of pressurized nitrogen for the international space station's ammonia coolant loops.

Read our full story.

FRIDAY, JUNE 6, 2008

The Discovery astronauts may be asked to collect a sample of the presumed grease seen inside the space station's left-side solar alpha rotary joint. NASA managers have not made a final decision, but engineers would like to get a sample to pin down where the grease might be coming from and astronaut Michael Fossum will be in the area during a third and final spacewalk Sunday.

Read our full story.

2005 GMT (4:05 p.m. EDT)

All of the electrically-driven bolts were engaged by 4:04 p.m. EDT, clearing the way for the station's robot arm to release the logistics module at its new orbital home on the roof of Japan's Kibo science laboratory.

2001 GMT (4:01 p.m. EDT)

The 16 attachment bolts are being driven to firmly connect the two modules together.

1954 GMT (3:54 p.m. EDT)

The berthing system has captured the logistics module for bolting to the lab.

1939 GMT (3:39 p.m. EDT)

The robot arm operators are getting the module lined up with the berthing port on the 16-ton Kibo lab. Mission Control has given a "go" for the installation.

1916 GMT (3:16 p.m. EDT)

The Japanese logistics module launched to the space station aboard shuttle Endeavour in March and temporarily placed atop the Harmony connecting module is on the move right now, more than 200 miles above the planet.

The station's robot arm, under the control of astronauts Karen Nyberg and Greg Chamitoff, has begun moving the 9,500-pound module toward its permanent residence atop the Kibo science laboratory attached to the outpost earlier this week.

1910 GMT (3:10 p.m. EDT)

All 16 bolts and the capture latches in the berthing port have freed the logistics module.

1857 GMT (2:57 p.m. EDT)

The first two sets of electrically-driven bolts that have held the logistics module to the Harmony module for the past two months have been released. The third set is driving open now, with another set still to be disengaged. There are four bolts in each set.

1822 GMT (2:22 p.m. EDT)

At 2:17 p.m. EDT, the space station's robotic arm grappled the Japanese logistics module mounted atop the Harmony connecting node in preparation for this afternoon's location. The module will be moved about 30 feet to its final home on the roof of Japan's Kibo science laboratory.

1250 GMT (8:50 a.m. EDT)

The Discovery astronauts are working through a busy day inside the international space station, continuing the outfitting of the Japanese Kibo laboratory module and preparing to move a smaller storage module to its permanent home on Kibo's upward-facing port.

Read our full story.

THURSDAY, JUNE 6, 2008
2216 GMT (6:16 p.m. EDT)

EVA ENDS. Repressurization of the Quest airlock module is underway, marking the official end of today's spacewalk by Mike Fossum and Ron Garan at 6:15 p.m. EDT.

The EVA lasted 7 hours and 11 minutes. That brings the total time for the two spacewalks conducted thus far during Discovery's mission to 13 hours and 59 minutes.

A final spacewalk is planned for Sunday starting around 10:30 a.m. EDT.

2200 GMT (6:00 p.m. EDT)

Toward the end of today's Kibo outfitting spacewalk, astronaut Michael Fossum removed a thermal cover over a section of the space station's left side solar alpha rotary joint for a quick inspection of its drive gear and bearing surfaces. He reported what looked like streaks of built-up grease but no signs of the sort of metallic filings and surface damage that have forced NASA to stop normal use of the station's right-side SARJ.

Read our full story.

2134 GMT (5:34 p.m. EDT)

Both spacewalkers are wrapping up their final tasks before heading back to the airlock shortly. Now passing the six-and-a-half-hour mark in the EVA.

2103 GMT (5:03 p.m. EDT)

Looking inside the port-side SARJ solar joint, Fossum says he doesn't see metal shavings or the damage like that seen on the starboard side. He did report noticing some lines or grooves.

2100 GMT (5:00 p.m. EDT)

Our STS-124 video collection for Spaceflight Now+Plus users now exceeds 100 movies. And we have a dozen high-definition videos available in our new HD section.

If you are not yet a subscriber, you can learn how to sign up here.

2040 GMT (4:40 p.m. EDT)

The faulty TV camera has been removed by the spacewalkers. Fossum will now go over to the port-side solar alpha rotary joint for a precautionary inspection. That joint has been operating perfectly, unlike the starboard-side that has experienced high vibrations and contamination damage.

2009 GMT (4:09 p.m. EDT)

Inside the space station, crewmembers have finished transferring racks and equipment out of the Japanese logistics module and into the Kibo science lab for today. The logistics module hatchway was just called, Mission Control says, in preparation for its relocation tomorrow.

Meanwhile, Fossum has traveled out to the port-side truss where an external television camera package is positioned. The faulty camera will be removed by the spacewalkers and brought inside the station at the conclusion of today's EVA.

1934 GMT (3:34 p.m. EDT)

Passing the four-and-a-half-hour mark in the EVA. Garan continues to work around the depleted nitrogen tank and Fossum around the new one.

1910 GMT (3:10 p.m. EDT)

Garan has been given a "go" from Houston to demate electrical connectors from the old nitrogen tank.

1858 GMT (2:58 p.m. EDT)

Mike Fossum is working at one of the station's external spare parts deck to loosen bolts holding the new nitrogen tank in its storage box.

1850 GMT (2:50 p.m. EDT)

Ron Garan is closing fluid lines and undoing quick-disconnects on the expended nitrogen tank located in the Starboard 1 truss of the space station. The nitrogen is used to pressurize cooling lines on the station. A fresh tank will be installed on Sunday during spacewalk No. 3.

1835 GMT (2:35 p.m. EDT)

Now Fossum and Garan are moving on, having finished the Kibo chores for today. They will be going over to the station truss structure to perform some prep work for replacing a nitrogen tank on the mission's third EVA and retrieving a troubled television camera assembly.

1815 GMT (2:15 p.m. EDT)

The spacewalkers have added some thermal sleeves over the trunnion pins and keel pins on Kibo that held the module in shuttle Discovery's payload bay during launch.

1755 GMT (1:55 p.m. EDT)

Work around the docking port on Kibo has been successfully completed by spacewalkers Mike Fossum and Ron Garan. The port is ready to receive the logistics module scheduled for relocation from the Harmony module tomorrow.

1746 GMT (1:46 p.m. EDT)

The next item on the to-do list is removing launch locks holding a debris shield in place around the docking port where the logistics module will be attached tomorrow.

1725 GMT (1:25 p.m. EDT)

The large blankets covering the docking port on the top-side of the Kibo laboratory are being removed by the spacewalkers. The logistics module launched to the station shuttle Endeavour in March and temporarily placed on the Harmony node will be relocated to its permanent home atop Kibo tomorrow.

1704 GMT (1:04 p.m. EDT)

Now passing the two-hour mark of the spacewalk. The thermal insulation and coverings have been removed from the robot arm. The crew is running about 25 minutes ahead of the timeline now.

1635 GMT (12:35 p.m. EDT)

The spacewalkers' next job is removing thermal covers from the joint electronics and the hand of the Kibo lab's robot arm.

1630 GMT (12:30 p.m. EDT)

Mission Control says the spacewalkers are right on the EVA timeline. Everything has been going smoothly.

1619 GMT (12:19 p.m. EDT)

Mike Fossum has completed the installation of the second camera on Kibo. The cameras will be critical to providing views of the lab's robotic arm when it comes to life on Saturday.

1615 GMT (12:15 p.m. EDT)

Installation of the first television camera has been accomplished.

1602 GMT (12:02 p.m. EDT)

Garan has put the first camera into its mounting port. The spacewalkers will now bolt it into place.

1545 GMT (11:45 a.m. EDT)

Working on the far end of the 37-foot-long Kibo science lab module, the spacewalkers are beginning the work to install a pair of television cameras.

1530 GMT (11:30 a.m. EDT)

Afer gathering their equipment from the airlock and establishing safety tethers, Fossum and Garan make their way to the Kibo module to begin today's work.

1505 GMT (11:05 a.m. EDT)

EVA BEGINS. The spacewalkers switched their suits to internal battery power at 11:04 a.m. EDT, marking the official start time for today's EVA by Mike Fossum and Ron Garan.

1503 GMT (11:03 a.m. EDT)

Depressurization has been completed and the outer hatch of the Quest airlock is open.

1431 GMT (10:31 a.m. EDT)

With the hatchway between the airlock and the rest of the space station now closed, depressurization of the airlock has begun ahead of schedule. Mission Control projects today's EVA could start about a half-hour early.

1420 GMT (10:20 a.m. EDT)

The spacewalking duo have entered into the airlock. The crew is running a bit ahead of the timeline this morning.

1315 GMT (9:15 a.m. EDT)

Astronauts Mike Fossum and Ron Garan are gearing up for a planned six-and-a-half-hour spacewalk today to mount cameras on Japan's Kibo lab module, remove launch locks and prepare a docking port for the attachment Friday of a Japanese logistics module.

Read our full story.

WEDNESDAY, JUNE 4, 2008

The 10 astronauts aboard the shuttle-space station complex opened up the newly installed Japanese Kibo module today at 5:05 p.m., floated inside and literally bounced off the walls, enjoying a chance for some impromptu zero gravity acrobatics in the roomy new addition.

Read our full story.

1630 GMT (12:30 p.m. EDT)

Cosmonaut-turned-plumber Oleg Kononenko replaced a pump in the space station's balky Russian toilet today and initial tests indicated the potty's urine collection system was working normally again. While engineers will monitor the toilet's operation to make sure the repair was, in fact, successful, they were hopeful a potentially difficult problem had been resolved.

Read our full story.

1505 GMT (11:05 a.m. EDT)

Expedition 17 flight engineer Oleg Kononenko tells the Russian mission control that the new pump has been installed in the space station toilet. Work to activate the hardware and determine if the toilet problems have been fixed will occur as the day continues.

Meanwhile, Discovery commander Mark Kelly and pilot Ken Ham have completed checking the sensor package on the heat shield inspection boom to verify the system is working properly after being stored on the station for the past two months.

1230 GMT (8:30 a.m. EDT)

The Discovery astronauts plan to enter and begin activating the Japanese Kibo laboratory module today after checking out sensors on their heat shield inspection boom and servicing the station's U.S. carbon dioxide removal system. Cosmonaut-turned-plumber Oleg Kononenko, meanwhile, plans to install a new pump in the space station's Russian toilet in a bid to repair the potty's urine collection system.

Read our full story.

TUESDAY, JUNE 3, 2008

The Discovery astronauts staged a successful spacewalk today, retrieving a shuttle heat shield inspection boom and testing techniques for cleaning metallic contamination from a critical solar array drive gear. They also prepared Japan's Kibo lab module for installation and Japanese astronaut Akihiko Hoshide, operating the station's robot arm, pulled the 15-ton module from Discovery's cargo bay and attached it to the station. If all goes well, the astronauts will enter the new module Wednesday to begin activating its myriad systems.

Read our full story.

2320 GMT (7:20 p.m. EDT)

Read our story on the spacewalk concluding.

2312 GMT (7:12 p.m. EDT)

EVA ENDS. Repressurization of the Quest airlock module began at 7:10 p.m. EDT, marking the official end of today's spacewalk by Mike Fossum and Ron Garan. The EVA lasted 6 hours and 48 minutes. It was the first of three spacewalk planned for Discovery's STS-124 mission.

2301 GMT (7:01 p.m. EDT)

KIBO INSTALLED. Japan's science laboratory module Kibo was successfully attached to the space station at 7:01 p.m. EDT.

"We have a new 'Hope' on the space station," astronaut Akihiko Hoshide radioed.

Kibo is the largest pressurized module for the international space station. It is 37 feet long and 14 feet in diameter, making it nearly 9 feet longer the U.S. Destiny lab and 14 feet longer than the European Columbus module.

2252 GMT (6:52 p.m. EDT)

The spacewalkers are climbing into the airlock to finish up today's EVA.

2242 GMT (6:42 p.m. EDT)

The first-stage capture of Kibo has been accomplished.

2238 GMT (6:38 p.m. EDT)

Kibo now sliding into port. Standing by for capture.

2235 GMT (6:35 p.m. EDT)

As the spacewalkers make their way back to the airlock, Kibo is moving the final feet to the berthing port.

2230 GMT (6:30 p.m. EDT)

The "go" has been given to connect Kibo to the space station.

2225 GMT (6:25 p.m. EDT)

Astronaut Mike Fossum closely inspected a previously seen defect in a bearing surface on the drive gear of a space station solar array rotary joint and confirmed it is a depression and not an area where debris had accumulated. That would seem to imply that it represents an area of the hardened surface material of the bearing race that has broken down somehow or otherwise been damaged as opposed to something that could be scraped away or smoothed out.

Read our story.

2206 GMT (6:06 p.m. EDT)

Kibo is being lined up with its mounting point on the port-side of the Harmony module.

2152 GMT (5:52 p.m. EDT)

The crew is wrapping up the SARJ work now and reinstalling covers around the joint. Based on Fossum's suit consumables, he needs to be back to the airlock by the six-hour, 30-minute mark of the spacewalk, or an hour from now.

2122 GMT (5:22 p.m. EDT)

Five hours into the EVA. Spacewalker Mike Fossum continues to test and evaluate the cleaning options while the station arm maneuvers Kibo to its new home in orbit.

2050 GMT (4:50 p.m. EDT)

Unberthing of Kibo from the payload bay is underway.

2048 GMT (4:48 p.m. EDT)

The payload retention latches that have held the Kibo module aboard shuttle Discovery were just opened in advance of the station arm lifting the massive lab.

2042 GMT (4:42 p.m. EDT)

Spacewalker Ron Garan has re-installed a trundle bearing assembly on the solar alpha rotary joint that had been removed previously as part of troubleshooting efforts.

2030 GMT (4:30 p.m. EDT)

The space station's robot arm has reached down to grapple the Kibo science laboratory for pulling the module out of shuttle Discovery's payload bay and attaching it to the Harmony node today.

2015 GMT (4:15 p.m. EDT)

In a pre-launch interview, spacewalker Mike Fossum talked about the solar alpha rotary joint cleaning techniques to be tried on Discovery's mission.

"We just recently squeezed in the SARJ cleaning task," Fossum said before launch. "It's really a test objective, to see what it would take to clan some of the metal that appears to be on the ring. We don't have a lot of information about it. So we're literally going out there with the kinds of tools you have in your garage.

"The first thing we're going to do is take a scraper to it and see if we can scrape some of that stuff off to make that surface a little more smooth for the rollers. Next, we're going to put down, literally, a little grease, it's a special space grease and then scrape on that and try to pick up material with it and wipe it off.

"And the third way is just putting down a little bit of this same grease and then taking a wipe, very much like a terry cloth towel, just to see if we can clean it up with this, knowing there's a very large ring out there and what we're trying to find is a technique that could be used to clean it up just a bit. But that's going to be a lot of work to go tackle the whole thing."

2010 GMT (4:10 p.m. EDT)

Spacewalkers Ron Garan and Mike Fossum removed protective covers, released window cover launch locks and disconnected shuttle power to prepare Japan's 15-ton Kibo laboratory module for its move from Discovery to the international space station. The astronauts are running about an hour ahead of schedule, more than making up for a 50-minute late start due to problems with a headset cable.

Read our story.

1950 GMT (3:50 p.m. EDT)

The spacewalkers have made their way out to the troubled station solar rotary joint. The massive ring that allows the starboard solar arrays to rotate in paddlewheel fashion has some kind of contamination in it. The astronauts will attempt some cleaning techniques, plus install a new trundle bearing assembly.

1922 GMT (3:22 p.m. EDT)

Now three hours into today's spacewalk. The work continues to go smoothly.

1912 GMT (3:12 p.m. EDT)

Mike Fossum has started releasing three bolts on the launch locks holding coverings that protected Kibo's windows during the trip to orbit. The windows will give good views of the lab's robot arm.

1843 GMT (2:43 p.m. EDT)

The spacewalkers are removing protective covers from the docking port on Kibo that will join the module to the space station.

1812 GMT (2:12 p.m. EDT)

Early preparations to ready the Kibo laboratory to be hoisted out of the payload bay have begun. Spacewalker Mike Fossum is removing power cables to the module that served as electrical umbilicals between the shuttle and Kibo.

Meanwhile, the shutle's inspection boom has been handed from the station arm to Discovery's arm.

1805 GMT (2:05 p.m. EDT)

Read our story on the boom's removal from the station.

1745 GMT (1:45 p.m. EDT)

After the power system was disconnected from the OBSS by the spacewalkers, the station arm began moving the boom into position for the upcoming handoff to the shuttle's robot arm. The station arm will then be able to relocate itself for unberthing the Kibo module from Discovery's payload bay later today.

1727 GMT (1:27 p.m. EDT)

The 50-foot-long space shuttle heat shield inspection boom has been retrieved from its stowage location on the space station truss structure by the station's arm. The spacewalkers will unhook keep-alive power umbilical system from the boom now.

The boom was anchored there for the last two months having been left by the shuttle Endeavour crew in March. A graphic showing the OBSS' installation to the station is posted here.

Unlike the previous shuttle missions that have included a boom in the payload bay, the Kibo science laboratory module launched aboard Discovery was too large for the sensor platform to be carried as well. So the Endeavour crew left its boom for the subsequent mission.

Later in Discovery's mission, the boom will be used to survey the shuttle's wings and nose cap to check for launch damage.

1710 GMT (1:10 p.m. EDT)

Garan has removed covers on the end of the boom that shielded the sensor package during this two-month storage in space. The shrouds guarded against contamination and helped with thermal protection.

1659 GMT (12:59 p.m. EDT)

Spacewalker Mike Fossum positioned on the side of the station's Harmony module reached over to the shuttle Discovery's extended robot arm and removed launch restraint straps on the elbow camera. The straps were put in place to ensure the camera wouldn't bump the Kibo module in the payload bay during launch. With the restraints now released, the camera is free to pan and tilt.

Meanwhile, Ron Garan has traveled to the station's Starboard 1 truss to begin disconnecting umbilicals routed to the stowed Orbiter Boom Sensor System. The OBSS inspection boom will be retrieved from the station for return to Discovery as today's spacewalk proceeds.

1645 GMT (12:45 p.m. EDT)

Floating in the space station's Quest airlock module, astronauts Michael Fossum and Ronald Garan switched their spacesuits to battery power at 12:22 p.m. to officially kick off a planned six-and-a-half-hour spacewalk. The spacewalk began 50 minutes behind schedule because of problems with a cable in Fossum's headset communications gear. After an equipment swap out, preparations continued normally.

Read our story.

1640 GMT (12:40 p.m. EDT)

Both spacewalkers have floated outside now. This is Fossum's fourth career spacewalk and the first by Garan.

1624 GMT (12:24 p.m. EDT)

EVA BEGINS. The airlock has been depressurized and the outer hatchway to space has swung open. The spacewalkers switched their suits to internal battery power at 12:22 p.m. EDT, marking the official start time for today's EVA by Mike Fossum and Ron Garan.

1552 GMT (11:52 a.m. EDT)

Depressurization of the Quest airlock has begun in preparation for today's spacewalk. The EVA start time is likely a half-hour away.

1535 GMT (11:35 a.m. EDT)

Fossum has now joined Garan inside the crewlock.

1530 GMT (11:30 a.m. EDT)

Garan is now inside the crewlock portion of the airlock and will be joined shortly by Fossum. Today's spacewalk is expected to start around 12 p.m. EDT, about 30 minutes later than originally planned.

1516 GMT (11:16 a.m. EDT)

It looks like that start of today's spacewalk is 25-30 minutes away, NASA commentator Rob Navias reports. Meanwhile, the SAFER jet backpacks are being attached to the spacewalkers suits. The backpack would be used in a emergency to rescue an astronaut who drifted from the space station.

1504 GMT (11:04 a.m. EDT)

A problem with Mike Fossum's communication cap worn inside his spacesuit helmet has forced the astronauts to back out of their spacewalk preparations so they can fix the cap. This will delay the start of today's spacewalk.

1432 GMT (10:32 a.m. EDT)

We are 24 minutes away from the start of airlock depressurization.

1350 GMT (9:50 a.m. EDT)

Designated EV1, Fossum, can be identified during the spacewalk by red stripes on his spacesuit. Garan who will use the call sign EV-2 has an unmarked suit.

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

Astronauts Michael Fossum and Ronald Garan are running a little ahead of schedule as they prepare their spacesuits and spacewalking gear for the start of today's excursion. A purge of the spacesuits is currently underway.

1230 GMT (8:30 a.m. EDT)

Astronauts Michael Fossum and Ronald Garan are gearing up for a six-and-a-half-hour spacewalk today to retrieve a shuttle heat shield inspection boom mounted on the international space station; prepare the huge Japanese Kibo lab module for installation; and attempt to clean contamination from a critical solar array rotary joint.

Read our full story.

MONDAY, JUNE 2, 2008

The shuttle Discovery's heat shield showed no obvious signs of damage during a slow back flip before docking today at the international space station. But it will take NASA managers several more days to complete their analysis and examination of high-resolution photos shot by the station crew.

Back at the Kennedy Space Center, meanwhile, an investigation has been launched to find out what caused extensive damage to launch pad 39A as it was pounded by Discovery's main engine and solid rocket booster exhaust plumes during liftoff Saturday.

Read our full story.

1936 GMT (3:36 p.m. EDT)

HATCHES OPEN. The hatchway between Discovery and the space station has been opened and the shuttle crew is being welcomed aboard the outpost now.

1900 GMT (3:00 p.m. EDT)

The shuttle Discovery glided to a gentle docking with the international space station today, wrapping up a two-day orbital rendezvous after pausing directly below the lab complex for a slow-motion back flip that gave the lab crew a chance to photograph the orbiter's heat shield.

Read our full story.

1818 GMT (2:18 p.m. EDT)

The docking ring between the two craft has been retracted into the shuttle's Orbiter Docking System, pulling the station to a tight mating. The hooks and latches are driving shut to firmly connect the two spacecraft.

Pressure and leak checks will be performed by the crews before the hatchway is opened.

1803 GMT (2:03 p.m. EDT)

CONTACT AND CAPTURE! Discovery has arrived at the space station carrying the Japanese science laboratory, the largest module for the complex.

The relative motions of the shuttle and station will be allowed to damp out over the next few minutes by the spring-loaded docking system. Later, the hooks and latches will be closed to firmly join the two craft and Discovery' Orbiter Docking System docking ring will be retracted to form a tight seal.

The opening of hatches between the station and shuttle is expected in about two hours. That will be followed by a welcoming ceremony and safety briefing.

1802 GMT (2:02 p.m. EDT)

Discovery and the station are four feet apart.

1801 GMT (2:01 p.m. EDT)

Less than 10 feet separating the shuttle from the station. Discovery's thrusters are programmed to fire in a post-contact maneuver to force the two docking ports together. That procedure is being armed.

1800 GMT (2:00 p.m. EDT)

The spacecraft are moving into an the orbital sunrise over the South Pacific.

1757 GMT (1:57 p.m. EDT)

The final approach beginning. The alignment between docking ports on Discovery and the space station is acceptable and no "fly out" maneuver by the shuttle is necessary.

1754 GMT (1:54 p.m. EDT)

About 50 feet left to go.

1751 GMT (1:51 p.m. EDT)

About 68 feet separate the shuttle and station.

1749 GMT (1:49 p.m. EDT)

Discovery is closing at about on-tenth of a foot per second.

1738 GMT (1:38 p.m. EDT)

Now about 185 feet from docking.

1724 GMT (1:24 p.m. EDT)

The shuttle's crew has been given a "go" for docking.

1722 GMT (1:22 p.m. EDT)

The shuttle is reaching the point directly in front of the station along the imaginary line called the velocity vector, or +V bar.

1712 GMT (1:12 p.m. EDT)

Discovery is marking the arc from the point beneath the station to a point in front of the complex to align with the docking port on the Harmony module. Docking is about 45 minutes away.

1708 GMT (1:08 p.m. EDT)

The pitch maneuver has been completed. Discovery is back in the orientation where it started, with the payload bay looking up at the station.

1705 GMT (1:05 p.m. EDT)

The main engine nozzles of Discovery are facing the station now as the shuttle points its tail upward.

1703 GMT (1:03 p.m. EDT)

This 360-degree, nose-first pirouette by Discovery gives the station crew about 100 seconds of quality photography time to snap detailed pictures of the orbiter's black tiles in the search for any launch impact damage.

1702 GMT (1:02 p.m. EDT)

The formal photo-taking period has started for the Expedition 17 crew, now that the shuttle has rotated its underside in view of the station complex.

1701 GMT (1:01 p.m. EDT)

Discovery is nose-up facing the station as the two craft fly more than 200 miles above the Atlantic.

1659 GMT (12:59 p.m. EDT)

The rendezvous pitch maneuver -- the 360-degree flip -- is beginning. The shuttle is the under the control of commander Mark Kelly, who is flying the ship from the aft flight deck.

As the shuttle's underside rotates into view, the station's crew will photograph Discovery's belly with handheld digital cameras equipped with 400- and 800-millimeter lenses.

The 800mm images should provide one-inch resolution for examination of landing gear door and external tank umbilical door seals. The 400mm will yield three-inch resolution.

After completing the RPM maneuver, Discovery will fly directly ahead of the space station with the shuttle's nose facing deep space and its cargo bay pointed at the lab complex. Then Kelly will guide the spacecraft to a docking with a pressurized mating adapter attached to the Harmony connecting module.

1657 GMT (12:57 p.m. EDT)

Discovery has reached a point about 600 feet directly beneath the station. The shuttle will hold this position until the RPM flip occurs a few minutes from now.

1651 GMT (12:51 p.m. EDT)

The shuttle is about 800 feet below the station.

1642 GMT (12:42 p.m. EDT)

Mission Control has given the "go" for the upcoming rendezvous pitch maneuver.

1640 GMT (12:40 p.m. EDT)

More photos showing the damage that pad 39A suffered during launch are posted here.

1617 GMT (12:17 p.m. EDT)

Distance between the shuttle and station is about one mile, closing at 9 feet per second. Discovery has completed a couple of available mid-course correction burns during this approach to the station.

1557 GMT (11:57 a.m. EDT)

Discovery is about 25,000 feet away from the station, closing at 14 feet per second.

1517 GMT (11:17 a.m. EDT)

TI burn. The shuttle has performed the Terminal Initiation burn to begin the final phase of today's rendezvous. The engine firing puts the shuttle on a trajectory to directly intercept the orbiting station over the next orbit and a half. This burn is the latest in a series of maneuvers performed by Discovery during its two days of chasing the station since launch Saturday.

Docking is anticipated shortly before 2 p.m. today.

1330 GMT (9:30 a.m. EDT)

The shuttle Discovery, carrying Japan's huge Kibo laboratory module, closed in on the international space station today, on course for docking around 1:54 p.m. EDT.

Read our preview story.

0415 GMT (12:15 a.m. EDT)

Launch pad 39A at the Kennedy Space Center suffered unusual damage during the shuttle Discovery's blastoff Saturday, NASA officials said Sunday.

Read our full story.

SUNDAY, JUNE 1, 2008

Close-up photos of the shuttle Discovery's external tank, shot as it drifted away from the orbiter Saturday, show a few relatively minor areas of foam loss but no major damage, NASA officials said today. Redesigned oxygen feedline brackets and new ice-frost ramps used to connect pressurization lines and a cable tray to the tank's skin - both recent post-Columbia safety upgrades - appeared to perform well. About five pieces of debris were seen falling away during launch from a camera mounted on the tank, but Mission Management Team Chairman LeRoy Cain said today it's not clear where the presumed foam might have originated.

Read our full story.

2035 GMT (4:35 p.m. EDT)

Space shuttle Discovery is about 600 miles behind the space station and closing at about 63 miles per orbit for tomorrow's docking.

The crew completed the inspection tasks today using the shuttle's robot arm. The astronauts said they did not see anything to be worried about. Further checks of the heat shield will occur as the mission proceeds.

1104 GMT (7:04 a.m. EDT)

Discovery's astronauts were just awakened to begin their first full day in space. Activities on the agenda today include using cameras on the shuttle's robot arm to perform surveys of the ship's heat shield to look for launch-impact damage, checking out the spacesuits to be used during the mission's spacewalks and preparing the docking system for Monday's linkup with the station.

Unlike the previous shuttle missions since the return-to-flight after the Columbia accident, Discovery is not carrying the 50-foot Orbiter Boom Sensor System (OBSS) for scanning the wings and nose cap. The Kibo laboratory payload is too big for the inspection boom to be carried during launch. The last shuttle flight in March left its boom at the station, so the Discovery crew will retrieve it Tuesday for full inspections later in the mission. Today's observations with the robot arm will be far less comprehensive than the laser package on the OBSS can accomplish.

SATURDAY, MAY 31, 2008
2325 GMT (7:25 p.m. EDT)

NASA Administrator Mike Griffin said today he's confident Russian space engineers will resolve technical problems with the Soyuz spacecraft that ferry Russian crews to and from the international space station. Griffin also said he was hopeful spare parts being launched to the station aboard the shuttle Discovery will help the crew repair the Russian toilet before it becomes a real problem.

Read our full story.

2309 GMT (7:09 p.m. EDT)

Mission Control just gave the astronauts a "go" for on-orbit operations following today's journey to space.

2305 GMT (7:05 p.m. EDT)

Both 60-foot-long payload bay doors of shuttle Discovery were opened about a half-hour ago, revealing the Kibo module to space. The orbiter's radiators have been deployed, and now the crew is working to set up the Ku-band communications antenna.

2230 GMT (6:30 p.m. EDT)

Right on time, the shuttle Discovery blasted into orbit Saturday, kicking off a two-week, three-spacewalk mission to attach Japan's huge Kibo laboratory module to the international space station and deliver a fresh flight engineer - Gregory Chamitoff - to replace outgoing station astronaut Garrett Reisman.

Read our full story.

2142 GMT (5:42 p.m. EDT)

T+plus 40 minutes, 20 seconds. The twin Orbital Maneuvering System engines on the tail of Discovery have been fired successfully to propel the shuttle the rest of the way to orbit.

2139 GMT (5:39 p.m. EDT)

T+plus 37 minutes, 37 seconds. The maneuvering engines have ignited for the orbit raising burn that also refines the path to the space station. This firing should last 2 minutes and 44 seconds.

2138 GMT (5:38 p.m. EDT)

T+plus 36 minutes. Discovery in the proper orientation for the upcoming maneuvering burn.

2129 GMT (5:29 p.m. EDT)

T+plus 27 minutes. A secondary set of electronics for steering the left orbital maneuvering engine has shut down, Mission Control says. But this should be no impact.

2124 GMT (5:24 p.m. EDT)

T+plus 22 minutes, 30 seconds. The post-launch dump of residual fuel from Discovery's main propulsion system has been performed.

2122 GMT (5:22 p.m. EDT)

T+plus 20 minutes. An image of the external tank foam debris is posted here. The debris shed about 18 seconds after booster separation.

A smaller piece was seen falling away from the tank 34 seconds about the boosters were jettisoned.

2116 GMT (5:16 p.m. EDT)

T+plus 14 minutes. The three Auxiliary Power Units are being shut down as planned.

2112 GMT (5:12 p.m. EDT)

T+plus 10 minutes. A large piece of foam was seen breaking free from the external tank shortly after separation of the twin solid rocket boosters. Video from a camera on the tank showed the piece did not strike the orbiter's right wing.

2111 GMT (5:11 p.m. EDT)

T+plus 9 minutes, 27 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.

2111 GMT (5:11 p.m. EDT)

T+plus 8 minutes, 50 seconds. The emptied external tank has been jettisoned from the belly of space shuttle Discovery. The tank will fall back into the atmosphere where it will burn up harmlessly.

2110 GMT (5:10 p.m. EDT)

T+plus 8 minutes, 32 seconds. MECO. Main Engine Cutoff confirmed! Discovery has reached orbit carrying the Japanese Kibo science laboratory destined for the space station.

2109 GMT (5:09 p.m. EDT)

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.

2108 GMT (5:08 p.m. EDT)

T+plus 7 minutes, 5 seconds. Discovery is 515 miles northeast of the launch pad, traveling at nearly 11,000 mph.

2108 GMT (5:08 p.m. EDT)

T+plus 6 minutes, 45 seconds. "Press to MECO" Discovery can now achieve a safe orbit on two engines. All three remain in good shape.

2108 GMT (5:08 p.m. EDT)

T+plus 6 minutes, 30 seconds. Discovery is 397 miles northeast of the launch pad, traveling at nearly 10,000 mph.

2108 GMT (5:08 p.m. EDT)

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

2107 GMT (5:07 p.m. EDT)

T+plus 5 minutes, 32 seconds. "Press to ATO". Discovery 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.

2106 GMT (5:06 p.m. EDT)

T+plus 4 minutes, 30 seconds. Discovery will be tripling its speed in the next four minutes to reach orbital velocity of 17,500 mph.

2106 GMT (5:06 p.m. EDT)

T+plus 4 minutes, 25 seconds. Discovery is 62 miles in altitude, 170 miles downrange from the launch pad, traveling at 5,300 mph.

2106 GMT (5:06 p.m. EDT)

T+plus 4 minutes. Negative return. The shuttle has passed the point where Discovery 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 Discovery in the unlikely event an abort occurs during the remainder of today's launch.

2105 GMT (5:05 p.m. EDT)

T+plus 3 minutes, 30 seconds. Discovery is 52 miles in altitude, 100 miles downrange from the launch pad.

2105 GMT (5:05 p.m. EDT)

T+plus 3 minutes. Commander Mark Kelly just received the "Two-engine Moron" call from CAPCOM Terry Virts in Mission Control. The call means Discovery can now reach a Transatlantic Abort Landing site if one main engine fails. However, all three engines continue to burn normally.

2105 GMT (5:05 p.m. EDT)

T+plus 2 minutes, 50 seconds. The twin Orbital Maneuvering System engines on the ship's tail have ignited to provide an extra boost in thrust in addition to Discovery's three main engines.

2104 GMT (5:04 p.m. EDT)

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

2104 GMT (5:04 p.m. EDT)

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. Discovery continues its nighttime streak toward space on the power generated by the three liquid-fueled main engines.

2104 GMT (5:04 p.m. EDT)

T+plus 1 minute, 50 seconds. Discovery is 22 miles in altitude, 23 miles downrange from the launch pad.

2103 GMT (5:03 p.m. EDT)

T+plus 1 minute, 45 seconds. Standing by for burn out and separation of the twin solid rockets. Commander Mark Kelly and pilot Ken Ham are joined on the flight deck by mission specialists Ron Garan and Karen Nyberg. Mike Fossum, Japanese astronauts Akihiko Hoshide and station-bound Greg Chamitoff are seated down on the middeck.

2103 GMT (5:03 p.m. EDT)

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.

2103 GMT (5:03 p.m. EDT)

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

2103 GMT (5:03 p.m. EDT)

T+plus 60 seconds. All systems are looking good one minute into the flight. Discovery is traveling on a northeastward trajectory toward orbit, its speed already in excess of 1,000 miles per hour as the main engines and twin solid rockets generate nearly 7 million pounds of thrust.

2102 GMT (5:02 p.m. EDT)

T+plus 35 seconds. Discovery's three liquid-fueled main engines are easing back to two-thirds throttle to reduce the aerodynamic stresses on the vehicle as it powers through the dense lower atmosphere and breaks the sound barrier.

2102 GMT (5:02 p.m. EDT)

T+plus 20 seconds. Discovery has maneuvered on the proper heading for rendezvous with the international space station on Monday to deliver Japan's world-class space laboratory.

2102:12 GMT (5:02:12 p.m. EDT)

T-minus 10 seconds, go for main engine start, fuel valves are opening, engine ignition, 3, 2, 1 and LIFTOFF! Kibo takes flight as Discovery clears the tower!

2101:41 GMT (5:01:41 p.m. EDT)

T-minus 31 seconds. AUTO SEQUENCE START! The handoff has occurred from the Ground Launch Sequencer to the space shuttle. Discovery's 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.

2101:12 GMT (5:01:12 p.m. EDT)

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; Discovery 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.

2100:42 GMT (5:00:42 p.m. EDT)

Now 90 seconds from launch. All remains "go" for liftoff of Discovery and the seven-astronaut crew at 5:02 p.m.

2100:12 GMT (5:00:12 p.m. EDT)

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.

2059:42 GMT (4:59:42 p.m. EDT)

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

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

And pilot Ken Ham has been asked to clear the caution and warning memory system aboard Discovery. 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.

2059:12 GMT (4:59:12 p.m. EDT)

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

2058:42 GMT (4:58:42 p.m. EDT)

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 today.

2058:12 GMT (4:58:12 p.m. EDT)

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 Discovery 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.

2057:12 GMT (4:57:12 p.m. EDT)

T-minus 5 minutes. The "go" has been given for for Auxiliary Power Unit start. Pilot Ken Ham is now flipping three switches in Discovery's cockpit to start each of the three APU's. The units, located in the aft compartment of Discovery, 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 Mark Kelly, 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.

2056:42 GMT (4:56:42 p.m. EDT)

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.

2056:12 GMT (4:56:12 p.m. EDT)

T-minus 6 minutes. Pilot Ken Ham 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.

2054:42 GMT (4:54:42 p.m. EDT)

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 Discovery a few hours ago. The arm can be re-extended very quickly should the need arise later in the countdown.

2054:12 GMT (4:54:12 p.m. EDT)

T-minus 8 minutes and counting. Pilot Ken Ham has flipped the switches in the cockpit of Discovery to directly connect the three onboard fuel cells with the essential power buses. Also, the stored program commands have been issued to the orbiter.

2053:12 GMT (4:53:12 p.m. EDT)

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 Discovery to complete their own automatic sequence of events through the final half minute of the countdown.

2050 GMT (4:50 p.m. EDT)

NASA launch director Mike Leinbach has conducted his poll and given approval to resume the countdown for liftoff at 5:02 p.m.

"Stand by for the greatest show on Earth," commander Mark Kelly responded.

2048 GMT (4:48 p.m. EDT)

The final readiness poll by the NASA test director Jeff Spaulding confirms there are no technical issues being addressed. The Range also reports "go" on the local weather. And Mission Control says that the abort landing site weather is acceptable, too.

2043 GMT (4:43 p.m. EDT)

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

2037 GMT (4:37 p.m. EDT)

The official launch window this afternoon now opens at 5:02:12 p.m. and closes at 5:08:59 p.m. EDT.

2032 GMT (4:32 p.m. EDT)

Now 30 minutes from Discovery's launch on an eight-and-a-half minute trek to space. At main engine cutoff, Discovery will be flying on a suborbital trajectory with a high point of 135 miles and low point of 35 miles. A half-hour later, the twin orbital maneuvering engines will be fired to place the shuttle into a 140 by 120 mile orbit.

2020 GMT (4:20 p.m. EDT)

At launch, the space station will be flying 210 miles above the Atlantic Ocean, southeast of Halifax, Nova Scotia. Liftoff at 5:02:12 p.m. EDT is timed to place Discovery on course to dock with the station shortly before 2 p.m. EDT on Monday.

2008 GMT (4:08 p.m. EDT)

T-minus 9 minutes and holding. Countdown clocks have gone into the planned 45-minute built-in hold. Today's launch remains set for 5:02 p.m. EDT.

2005 GMT (4:05 p.m. EDT)

Mission Control in Houston has loaded Discovery's onboard computers with the proper guidance parameters based on the projected launch time.

2003 GMT (4:03 p.m. EDT)

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

2002 GMT (4:02 p.m. EDT)

Now one hour away from launch of Discovery.

2001 GMT (4:01 p.m. EDT)

Pilot Ken Ham is configuring the displays inside Discovery's cockpit for launch while commander Mark Kelly enables the abort steering instrumentation.

1957 GMT (3:57 p.m. EDT)

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 5:02 p.m.

Discovery's 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.

1954 GMT (3:54 p.m. EDT)

The work to seal the shuttle's crew compartment hatch for flight is complete. And the closeout team that assisted the astronauts into Discovery this afternoon are preparing to leave the launch pad now.

1947 GMT (3:47 p.m. EDT)

T-minus 20 minutes and holding. The countdown has paused for a 10-minute built-in hold. Launch is scheduled for 5:02 p.m. EDT. Everything is going smoothly with the countdown and current weather conditions are beautiful.

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.

1937 GMT (3:37 p.m. EDT)

Commander Mark Kelly has pressurized the gaseous nitrogen system for Discovery's Orbital Maneuvering System engines and pilot Ken Ham activated the gaseous nitrogen supply for the orbiter's Auxiliary Power Units' water spray boilers.

1928 GMT (3:28 p.m. EDT)

The ground pyro 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.

1907 GMT (3:07 p.m. EDT)

Now passing the T-minus 1 hour mark in the countdown. Two scheduled holds are planned at T-minus 20 minutes and T-minus 9 minutes, leading to the target liftoff time of 5:02 p.m. EDT.

The final pre-flight alignment of Discovery's guidance system inertial measurement units is underway.

1904 GMT (3:04 p.m. EDT)

And now Discovery's crew module hatch is swinging shut for launch.

1902 GMT (3:02 p.m. EDT)

Just two hours remain until the planned liftoff time. The "go" has been given to close Discovery's hatch.

1837 GMT (2:37 p.m. EDT)

T-minus 90 minutes and counting. Countdown clocks continue to tick down to T-minus 20 minutes where the next hold is planned. Countdown activities remain on track for liftoff at 5:02 p.m. There are no technical issues being worked and weather continues to be acceptable.

At this point in the count, the Ground Launch Sequencer software that will control the final nine minutes of the countdown has been initialized. Also, the solid rocket boosters' gas generator heaters in the hydraulic power units are turned on, the aft skirt gaseous nitrogen purge is starting and the rate gyro assemblies (RGAs) are being activated. The RGAs are used by the orbiter's navigation system to determine rates of motion of the boosters during the first stage of flight.

1821 GMT (2:21 p.m. EDT)

The final crewmember just boarded Discovery. Ron Garan serves as mission specialist No. 2 and the flight engineer on STS-124. He will ride in the flight deck's aft-center seat.

Read his biography here.

1811 GMT (2:11 p.m. EDT)

Japanese astronaut Akihiko Hoshide serves as mission specialist No. 4 on Discovery's STS-124 flight. He just entered the orbiter to take the center seat on the middeck.

Read his biography here.

1808 GMT (2:08 p.m. EDT)

Rookie astronaut Karen Nyberg is mission specialist No. 1 for Discovery. She is climbing to the flight deck's aft-right seat.

Read his biography here.

1802 GMT (2:02 p.m. EDT)

Three hours and counting until liftoff time.

1755 GMT (1:55 p.m. EDT)

Mission specialist No. 3 for STS-124, Mike Fossum, just entered the orbiter to take the middeck's left seat.

Read his biography here.

1752 GMT (1:52 p.m. EDT)

Ken Ham, the pilot of Discovery, is making his way to the flight deck's front-right seat.

Read his biography here.

1742 GMT (1:42 p.m. EDT)

Station-bound crewmember Greg Chamitoff, a rookie NASA astronaut, has boarded Discovery to take the middeck's right-side seat. He will move aboard the station for an extended stay as part of the Expedition crew, replacing astronaut Garret Reisman.

Read his biography here.

1738 GMT (1:38 p.m. EDT)

Commander Mark Kelly is the first astronaut to board the shuttle. He is taking the forward-left seat on the flight deck.

Read his biography here.

1731 GMT (1:31 p.m. EDT)

Discovery's crew arrived at launch pad 39A at 1:31 p.m. The AstroVan came to a stop on the pad surface near the Fixed Service Structure tower elevator that will take the seven-man crew to the 195-foot level to begin boarding the shuttle.

1722 GMT (1:22 p.m. EDT)

The AstroVan is passing the 52-story Vehicle Assembly Building where Discovery 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 at the passing convoy. This is a launch day tradition to say farewell and good luck to the astronaut crews.

1712 GMT (1:12 p.m. EDT)

Commander Mark Kelly, pilot Ken Ham, mission specialists Karen Nyberg, Ron Garan, Mike Fossum, Akihiko Hoshide and station-bound astronaut Greg Chamitoff just departed the Kennedy Space Center crew quarters to board the AstroVan for the 20-minute ride from the Industrial Area to launch pad 39A on the edge of the Atlantic Ocean.

1707 GMT (1:07 p.m. EDT)

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 5:02 p.m. EDT launch time.

1645 GMT (12:45 p.m. EDT)

The crew has donned the 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 1:12 p.m.

1635 GMT (12:35 p.m. EDT)

Commander Mark Kelly, pilot Ken Ham and flight engineer Ron Garan have received a weather briefing on conditions at the Kennedy Space Center and the primary abort landing sites. Weather is not expected to be a constraint to launching on time today.

1620 GMT (12:20 p.m. EDT)

The countdown is proceeding smoothly with no significant technical issues. The weather predictions still look good for the 5:02 p.m. EDT launch of Discovery.

1530 GMT (11:30 a.m. EDT)

The Final Inspection Team is performing its observations of Discovery this morning.

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.

1445 GMT (10:45 a.m. EDT)

FUELING COMPLETED. The external fuel tank has been pumped full with a half-million gallons of supercold liquid oxygen and liquid hydrogen. The three-hour fueling process started at 7:38 a.m. with the chilldown conditioning and was completed at 10:36 a.m.

But given the cryogenic nature of the oxidizer and propellant, the supplies naturally boil away. So the tanks are continuously topped off until the final minutes of the countdown in a procedure called "stable replenishment."

With the hazardous tanking operation completed, the Orbiter Closeout Crew and Final Inspection Team have been given the OK to go out to the pad to perform their jobs. The closeout crew will ready Discovery's 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.

1330 GMT (9:30 a.m. EDT)

Filling of the space shuttle's external fuel tank takes about three hours to complete, and keeping the tank fully loaded continues until just minutes before liftoff time.

The process starts with the chilldown thermal conditioning of the system, followed by a slow-fill mode and then the fast-fill mode. The tank then enters a stable replenishment mode that ensures the liquid hydrogen and liquid oxygen supplies are topped off through the final minutes of the countdown.

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

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.

1250 GMT (8:50 a.m. EDT)

The liquid hydrogen low-level engine cutoff sensors in the bottom of the external tank have undergone initial testing today after they were submerged by propellant during the first hour of fueling. The launch team sent commands to test the health of the sensors and a NASA spokesman says the expected readings were received from the sensors, indicating all four are working properly.

1150 GMT (7:50 a.m. EDT)

FUELING UNDERWAY. The filling of space shuttle Discovery's external fuel tank with a half-million gallons of supercold propellants has begun at launch pad 39A.

The tanking operation commenced with the chilldown thermal conditioning process at 7:38 a.m.

The Mission Management Team met earlier this hour and gave the "go" to begin fueling. Engineers in Firing Room 4 then started the three-hour fueling process as scheduled.

The coundown has resumed ticking after the two-hour planned hold at the T-minus 6 hour mark. The next scheduled hold occurs at T-minus 3 hours.

Liftoff is targeted for precisely 5:02:12 p.m. EDT.

The weather forecast remains 80 percent "go" this afternoon.

0145 GMT (9:45 p.m. EDT Fri.)

As the sun set on Kennedy Space Center this evening, the rotating service structure moved away from the space shuttle to reveal Discovery at pad 39A for Saturday afternoon's liftoff carrying the largest module for the space station -- Japan's Kibo laboratory.

Work overnight will include activating the orbiter's inertial measurement units and power-generating fuel cells, plus checking all of the switches in Discovery's cockpit to ensure they are in the correct positions for launch.

At 12:37 a.m. EDT, countdown clocks will resume ticking following the half-day hold at the T-minus 11 hour mark. The count will proceed down to the T-minus 6 hour point where a two-hour begins at 5:37 a.m. EDT. During that pause, the launch team will verify all systems are ready to begin loading a half-million gallons of supercold rocket fuel in the shuttle's external tank.

The three-hour fueling process is scheduled to commence at 7:37 a.m. EDT, pending a final "go" from the Mission Management Team's 7 a.m. meeting to review the status of the count and the latest weather outlook.

The seven astronauts will be awakened at 6:30 a.m., although they could sleep another hour if the crew wishes. Their launch day routine leads to suitup at 12:42 p.m., departure from crew quarters at 1:12 p.m. and arrival at the launch pad around 1:40 p.m. to start strapping aboard the shuttle.

Flight controllers at the Johnson Space Center in Houston, meanwhile, have made a slight adjustment to the shuttle's launch window. For the desired flight day three rendezvous with the space station, the window will open at 5:01:15 p.m. for an "in-plane" launch 57 seconds later at 5:02:12 p.m. The flight day three window will close at 5:07:12 p.m., but a flight day four window is available, permitting a launch as late as 5:10:23 p.m., if the weather or some other problem prevents launch during the desired flight day 3 window.

So if all goes per the plan, Discovery should blast off at exactly 5:02:12 p.m. EDT (2102:12 GMT).

0120 GMT (9:20 p.m. EDT Fri.)

The gantry-like rotating service structure at launch pad 39A has been rolled away from space shuttle Discovery in preparation for its upcoming launch. The giant structure began to swing open at approximately 8:30 p.m. and its move was completed by 9 p.m.

FRIDAY, MAY 30, 2008
1230 GMT (8:30 a.m. EDT)

Space shuttle Discovery's electricity-producing fuel cells have been successfully loaded with liquid hydrogen and liquid oxygen reactants as the countdown continues for Saturday's launch.

Today's planned activities include final tests of the three main engines, 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.

Countdown clocks will enter the lengthy T-minus 11 hour planned hold period at 11 a.m. EDT. The built-in hold will last 13 hours and 37 minutes.

The giant gantry-like rotating service structure is scheduled for retracting from around Discovery at 8:30 p.m., marking a key milestone to ready the shuttle and launch pad for Saturday morning's fueling of the external tank.

The weather predictions for Saturday continue to look favorable with just some scattered clouds, good visibility, southeasterly winds of 10 peaking to 17 knots and a temperature of 80 degrees F. There is an 80 percent chance of acceptable conditions at the 5:02 p.m. EDT launch time.

"A high pressure ridge is located north of Florida, and east-southeasterly flow is prevalent over Kennedy Space Center. Weather will be similar on launch day," today's weather update said.

"Isolated coastal showers may be in the area during the morning hours, but a sea breeze will develop in the afternoon, clearing the coast and causing showers to move inland. With this weather pattern, weather is favorable for launch, with only a slight concern for anvils returning toward the east coast from inland thunderstorms. Our primary concern for launch is anvils moving toward KSC from the northwest.

Should the launch be delayed for some reason, the odds of good weather worsen to 70 percent on Sunday and just 40 percent on Monday.

"Sunday, a trough moves into North Florida causing more potential for thunderstorms northwest of KSC, and an increased chance for anvils to threaten the area. Monday, the trough progresses closer to the Central Florida area. The ridge shifts to the south of KSC, and the sea breeze convergence and associated showers and thunderstorm will be lingering near the east coast of Central Florida."

THURSDAY, MAY 29, 2008
1800 GMT (2:00 p.m. EDT)

A replacement pump and other equipment needed to repair the Russian toilet aboard the international space station was installed in the shuttle Discovery early today as engineers readied the ship for blastoff Saturday on a long-awaited flight to deliver Japan's huge Kibo laboratory module to the orbiting outpost.

Read our full story.

1510 GMT (11:10 a.m. EDT)

The Mission Management Team concluded its meeting this morning with a "go" to continue the countdown. There are no significant problems being worked with Discovery and the count remains on schedule for a liftoff at 5:02 p.m. EDT on Saturday.

"We are not carrying any constraints," says MMT chairman LeRoy Cain.

At launch pad 39A, technicians are preparing to load liquid hydrogen and liquid oxygen into Discovery's electricity-generating fuel cells. The units combine the cryogenic reactants to produce power and drinking water during the shuttle's mission.

The cryogenics will flow into storage spheres located beneath the payload bay. Once the tanks are loaded, about 240 pounds of liquid oxygen will be allowed to boil off starting around 7 p.m. tonight, launch director Mike Leinbach says, due to weight and shuttle center-of-gravity considerations for this mission.

Discovery's seven astronauts are undergoing their final medical exams today. Later, they will enjoy some flight time aboard the T-38 training jets and meet with the president of Japan's space agency.

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

Russian replacement parts for the space station's broken toilet arrived at the Kennedy Space Center last night and were swiftly packed aboard shuttle Discovery for launch. Photos showing technicians moving the container through Discovery's crew module hatch are available here and here.

The Mission Management Team is meeting right now for the standard Launch Minus-2 Day review to discuss the status of pre-flight work on Discovery and any lingering issues. This review determines whether to proceed with the launch. The traditional pre-launch news conference will follow the MMT meeting, currently scheduled to begin at 11 a.m. EDT.

Meanwhile, Air Force weather forecasters continue to predict an 80 percent chance of favorable conditions on Saturday for the 5:02 p.m. EDT liftoff time. However, the latest outlook for the backup launch opportunities on Sunday and Monday has worsened a bit. The odds of good weather on those days are now 70 percent and 60 percent, respectively.

"Sunday, an upper level trough moves into Florida causing more potential for thunderstorms northwest of KSC, and an increased chance for anvils to threaten the area," forecasters said today. "Monday, there will be an increase in moisture as a weak boundary moves into North Florida increasing the potential for anvils and showers to be in the KSC area by launch time."

WEDNESDAY, MAY 28, 2008
1901 GMT (3:01 p.m. EDT)

Countdown clocks have started ticking toward Saturday's planned liftoff of the space shuttle Discovery.

Launch team members gathered for the "call to stations" at 2:30 p.m. EDT, and then the three-day countdown commenced at 3 p.m. as scheduled.

Clocks currently read T-minus 43 hours and counting. But a series of holds are timed throughout the next few days, leading to Saturday's targeted liftoff time of 5:02 p.m. EDT.

The early portion of the count involves buttoning up launch pad equipment and removing platforms inside the shuttle's crew module, reviewing flight software stored in Discovery's mass memory units, loading backup software into the general purpose computers and testing navigation systems.

1750 GMT (1:50 p.m. EDT)

Shuttle crew flies to the Cape for start of countdown
The shuttle Discovery's international crew flew to the Kennedy Space Center today for the afternoon start of their countdown to blastoff Saturday on a mission to attach Japan's huge Kibo lab module to the international space station.

Read our full story.

1630 GMT (12:30 p.m. EDT)

The six-man, one-woman crew for shuttle Discovery's upcoming mission to the space station just arrived at the Kennedy Space Center to begin the final three days of pre-flight preparations.

Flying in sleek T-38 training jets, the astronauts began touching down on the spaceport's shuttle runway at 12:06 p.m. All four aircraft were on the ground by 12:24 p.m.

"It's great to be here today," commander Mark Kelly said.

1545 GMT (11:45 a.m. EDT)

Crew arrival is now expected a little past noon.

1407 GMT (10:07 a.m. EDT)

Spare parts for the space station's toilet, which has experienced problems in recent days, are being shipped to the Cape from Russia for launch aboard shuttle Discovery. About 35 pounds of equipment should arrive at Kennedy Space Center around 10 p.m. tonight to be loaded in Discovery's middeck early tomorrow, says Scott Higginbotham, the mission's payload manager.

1402 GMT (10:02 a.m. EDT)

"We are tracking no issues," Charlie Blackwell-Thompson, NASA test director, said at this morning's countdown news briefing.

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

The space shuttle Discovery's seven astronauts will arrive at Kennedy Space Center this morning and the countdown clocks begin ticking later today for Saturday's scheduled launch.

Commander Mark Kelly, pilot Ken Ham, mission specialists Karen Nyberg, Ron Garan, Mike Fossum, Akihiko Hoshide and station-bound astronaut Greg Chamitoff are flying in from their training base in Houston. Touchdown at the Kennedy Space Center is expected around 11:30 a.m. EDT.

In Firing Room 4 of the Launch Control Center, technicians are preparing to start the three-day countdown sequence at 3 p.m. EDT.

Liftoff of Discovery to deliver the Japanese science laboratory module to the space station remains targeted for Saturday at 5:02 p.m. EDT.

The early weather outlook is favorable. Meteorologists predict an 80 percent chance of acceptable conditions at launch time, with just some scattered clouds, good visibility, southeasterly winds of 10 peaking to 17 knots and a temperature of 80 degrees F.

"A high pressure ridge is located north of Florida, and easterly flow is prevalent over Kennedy Space Center causing occasional morning coastal showers. Winds will become more southeasterly on launch day. Isolated coastal showers will be in the area during the morning hours, but a sea breeze will develop in the afternoon, clearing the coast and causing showers to move inland. With this weather pattern, weather looks favorable for launch, with only a slight concern for anvils returning toward the east coast from thunderstorms along the west coast sea breeze," Air Force forecasters said.

"Our primary concern for launch time is anvils moving toward the east coast of Florida from the west.

"By Monday, there will be an increase in moisture over Florida causing a greater concern for anvils and showers in the KSC area."

The official odds for the backup launch opportunities on Sunday and Monday are 80 percent and 70 percent favorable, respectively. A chart of launch windows is available here.

MONDAY, MAY 19, 2008

NASA managers Monday cleared the shuttle Discovery for launch May 31 on a three-spacewalk mission to deliver and attach Japan's huge Kibo laboratory module to the international space station. The decision to proceed came after a lengthy discussion on the health of the station's Soyuz lifeboat after back-to-back re-entry problems that led to rough, off-course landings.

Read our full story.

FRIDAY, MAY 9, 2008

The crew of the shuttle Discovery strapped in Friday for a dress-rehearsal countdown that sets the stage for launch May 31 on a long-awaited flight to deliver Japan's huge Kibo laboratory module to the space station.

Read our full story.

TUESDAY, MAY 6, 2008

Shuttle Discovery's astronauts flew into Kennedy Space Center on Tuesday afternoon for this week's countdown dress rehearsal and emergency training drills at launch pad 39A.

Read our full story.

SATURDAY, MAY 3, 2008

With four weeks until its planned launch to haul the Japanese science laboratory module up to the space station, shuttle Discovery traveled overnight from the Vehicle Assembly Building to pad 39A.

Read our full story.

SATURDAY, APRIL 26, 2008

Shuttle Discovery was transferred from its hangar to the Vehicle Assembly Building on Saturday morning where the spacecraft will be hooked up to its external fuel tank and twin solid rocket boosters in preparation for rollout to the launch pad.

Read our full story.