BY JUSTIN RAY

Follow the return America's space shuttle fleet to flight as we chronicle Discovery's mission to the international space station.

0859 GMT (4:59 a.m. EDT)

Pilot Jim Kelly has completed the auxiliary power unit prestart, which positions switches in the cockpit in the ready-to-start configuration. One of the three APUs will be started just prior to the deorbit burn.

0854 GMT (4:54 a.m. EDT)

A steering check of the Discovery's twin orbital maneuvering system engines on the tail of the shuttle is now beginning. The engines will perform the deorbit burn to slow the ship for entry into the atmosphere this morning.

0850 GMT (4:50 a.m. EDT)

Radar is showing a couple of small showers popping up inside the 30-mile zone around the runway. Rominger is going to fly over and take a look at this area, which is offshore to the northeast.

0839 GMT (4:39 a.m. EDT)

In a positive step to potentially bringing Discovery home to the Kennedy Space Center at sunrise this morning, entry flight director LeRoy Cain has instructed the astronauts to begin the "fluid loading" protocol. Typically, the crew is allowed to hold off drinking the large quantities of liquids unless there's a reasonable chance of landing on the next available opportunity.

Clouds around the Cape and rainshowers off the coast continue to be assessed to ensure the weather conditions do not violate any of the landing rules. A final "go/no go" decision for the deorbit burn is expected around 5:15 a.m.

0830 GMT (4:30 a.m. EDT)

The crew is beginning an alignment of the shuttle's inertial measurement unit guidance computers.

0825 GMT (4:25 a.m. EDT)

A decision point on this next landing opportunity is coming up in about 10 minutes. That is when the crew would need to begin their "fluid loading" to take salt tablets and drink several quarts of water to restore fluids lost during two weeks spent in microgravity.

0800 GMT (4:00 a.m. EDT)

Chief NASA astronaut Kent Rominger is back at work, flying around Central Florida to examine clouds and the rainshowers offshore. He is relaying his observations to astronaut Rick Sturckow in Houston for input into the decision making process this morning.

0737 GMT (3:37 a.m. EDT)

Now two hours from the next deorbit burn window to bring Discovery back to Kennedy Space Center, weather permitting. If the shuttle is able to land on that orbit, touching down in Florida at 6:42 a.m. EDT, the STS-114 mission will have lasted 13 days, 20 hours and 3 minutes, spanning 5,745,051 miles.

0722 GMT (3:22 a.m. EDT)

A map showing the path Discovery would follow into the Kennedy Space Center for landing at 6:42 a.m. EDT is available here. The track would give residents along the U.S. Gulf Coast the chance to see Discovery's entry and fiery plasma trail.

0715 GMT (3:15 a.m. EDT)

Chief NASA astronaut Kent Rominger has just landed in the Shuttle Training Aircraft for refueling. He'll return to the skies in a little while to resume weather reconnaissance flights around the Kennedy Space Center runway.

0703 GMT (3:03 a.m. EDT)

WAVE OFF. This morning's first chance to bring space shuttle Discovery back to Earth has been scrubbed due to unacceptable weather conditions at the Kennedy Space Center in Florida due to rainshowers and thunderstorms within 30 miles of the runway. Discovery will circle the planet one more time while flight controllers watch the weather. If Mother Nature decides to cooperate, Discovery could fire its braking engines at 5:37 a.m. EDT for KSC touchdown at 6:42 a.m. EDT.

NASA's backup plan if the weather remains unfavorable at the Florida spaceport this morning is diverting Discovery to the alternate landing site at Edwards Air Force Base in California's Mojave Desert. The first Edwards opportunity would begin with a deorbit burn at 7:07 a.m. EDT and landing at 8:11 a.m. EDT.

0657 GMT (2:57 a.m. EDT)

The official weather forecast for the first KSC landing opportunity has been presented to the flight control team. The forecast is "no go" for Discovery's homecoming. A wave off is expected momentarily.

0640 GMT (2:40 a.m. EDT)

The crew should be suiting up in their day-glow orange partial pressure suits worn during launch and entry. A decision on whether to continue pressing ahead with the first landing opportunity is expected to be made around 3 a.m.

0621 GMT (2:21 a.m. EDT)

CAPCOM Ken Ham just told the astronauts that the weather is "not looking great" for the first landing opportunity this morning. The official weather forecast has been revised to include rainshowers within 30 miles of the runway. Earlier, the forecast called for a "slight chance" of showers.

0614 GMT (2:14 a.m. EDT)

If the weather precludes the first landing opportunity this morning, the second and final shot to land at Kennedy Space Center would begin with a deorbit burn at 5:37 a.m. and a daytime touchdown at 6:42 a.m. EDT.

0607 GMT (2:07 a.m. EDT)

The astronauts are still marching through the deorbit preparation checklist. Ignition of the two-minue, 43-second burn would occur at 4:01:32 a.m. EDT to slow Discovery by about 275 feet per second to slip from orbit and begin the hour-long glide to Kennedy Space Center.

0526 GMT (1:26 a.m. EDT)

The crew has been given a "go" to transition Discovery's onboard computers from the OPS-2 software used during the shuttle's stay in space to OPS-3, which is the software package that governs entry and landing.

0525 GMT (1:25 a.m. EDT)

Discovery's payload bay doors have been shut and sealed for the space shuttle's fiery reentry into Earth's atmosphere this morning.

And Discovery will soon maneuver to a new orientation in space to improve the communications link with NASA's orbiting data relay satellites.

0522 GMT (1:22 a.m. EDT)

Payload bay door closure is underway.

0520 GMT (1:20 a.m. EDT)

"OK, Eileen, once again the word of the evening for weather at the Cape is instability," CAPCOM astronaut Ken Ham just radioed Discovery commander Eileen Collins. "Right now we are watching some cells popping up within the 30-mile circle, over the water, probably in the vicinity of 20 to 25 miles off the coast. (Weather reconnaissance astronaut pilot Kent Rominger) is reporting that they are building up fairly high...and they do have some electrical activity associated with them. So we are watching all of that. Our optimism isn't as high as it was earlier. Obviously, we are going to ask you to keep going along the timeline, and we're going to look real hard at the decision for fluid loading with respect to this (landing opportunity) because we understand the situation we are in with you and the whole day ahead of you."

"Discovery copies all that, thank you," Collins replied.

The fluid loading is the protocol of the astronauts drinking large amounts of fluids to help in their readaptation to Earth's gravity. Starting to drink in preparation for this first landing opportunity is not something flight controllers will decide to approve unless there's some chance of weather cooperating.

0515 GMT (1:15 a.m. EDT)

Discovery's astronauts have been given approval to close and lock the 60-foot long payload bay doors as activities continue for the day's first deorbit and landing opportunity. Weather continues to be watched closely at the Kennedy Space Center, with showers offshore and clouds around the area.

0511 GMT (1:11 a.m. EDT)

Entry flight director LeRoy Cain is polling the Mission Control team for a "go" to close the payload bay doors.

0440 GMT (12:40 a.m. EDT)

Good morning from Kennedy Space Center where there's a star-filled sky overhead and preparations are well underway for landing of shuttle Discovery at 5:07 a.m. EDT (0907 GMT). The astronauts are stepping through the deorbit prep timeline and should close the payload bay doors in about 40 minutes. The strategy is targeting the two KSC landing opportunities this morning, then divert to Edwards Air Force Base in California if the Florida weather does not cooperate. Meteorologists say there is much less moisture in the air around the KSC today than yesterday, but there remains a slight concern for showers within 30 miles of the runway.

MONDAY, AUGUST 8, 2005
0955 GMT (5:55 a.m. EDT)

Uncertainty about dynamic weather at the Kennedy Space Center forced entry flight director LeRoy Cain to pass up two landing opportunities today and to keep the shuttle Discovery's crew in orbit an extra 24 hours. Read our full story.

0940 GMT (5:40 a.m. EDT)

The forecast for Kennedy calls for just a few clouds at 2,000 feet and 10,000 feet, scattered clouds at 25,000 feet with a slight chance of showers within 30 nautical miles. Winds will be out of 220 degrees at three knots with peaks to five knots, well within NASA's crosswind limits.

At Edwards, the outlook is for few clouds at 10,000 feet, scattered clouds at 25,000 feet and winds from 220 degrees at four knots peaking to seven knots.

White Sands is expecting a slight chance of showers and broken cloud decks at 10,000 and 25,000 feet.

0932 GMT (5:32 a.m. EDT)

Discovery's onboard computers are transitioning from the entry and landing software package back to the on-orbit software.

0921 GMT (5:21 a.m. EDT)

Discovery's payload bay doors have been reopened as the astronauts begin backing out of the deorbit preparations.

0904 GMT (5:04 a.m. EDT)

ANOTHER DAY IN SPACE! Unstable weather conditions and low clouds aren't going to cooperate at Kennedy Space Center this morning, forcing space shuttle Discovery to remain in orbit for an additional day. Tomorrow's first landing opportunity would be 5:08 a.m. EDT at the Cape. NASA will activate the backup landing site at Edwards Air Force Base in California. The space agency intends to get Discovery back on Earth tomorrow at either Kennedy Space Center or Edwards.

Here are all possible landing times, including targets for White Sands, N.M. (in EDT)

ORBIT...DEORBIT......LANDING...SITE

Tuesday, Aug. 9

217.....04:05 AM.....05:08 AM...Kennedy Space Center
218.....05:37 AM.....06:39 AM...White Sands, NM
218.....05:41 AM.....06:43 AM...Kennedy Space Center
219.....07:11 AM.....08:13 AM...Edwards AFB, CA
219.....07:13 AM.....08:14 AM...White Sands, NM
220.....08:47 AM.....09:48 AM...Edwards AFB, CA

0902 GMT (5:02 a.m. EDT)

Controllers just told the crew they'd be briefed on the situation momentarily.

0853 GMT (4:53 a.m. EDT)

Flight director LeRoy Cain is getting a final assessment on the weather conditions before he makes the "go/no go" decision on the deorbit burn to bring Discovery home today.

0845 GMT (4:45 a.m. EDT)

Clocks are counting down to the deorbit burn now 30 minutes away. Officials are still working the weather to determine if it'll be safe to allow Discovery to head for landing at Kennedy Space Center at 6:22 a.m. this morning.

0827 GMT (4:27 a.m. EDT)

Discovery is passing over the equator west of South America to begin its 202nd orbit of the mission.

0819 GMT (4:19 a.m. EDT)

Chief NASA astronaut Kent Rominger aboard the Shuttle Training Aircraft just made a dive into Runway 15 to evaluate the weather conditions. There's still some low clouds in the area around 700 feet.

0810 GMT (4:10 a.m. EDT)

After a clearing of the low clouds over the past half-hour, more clouds seem to be moving in again.

0800 GMT (4:00 a.m. EDT)

Discovery is flying over the extreme southern Pacific southeast of Australia on its 201st orbit of Earth. The "go/no go" for this upcoming deorbit burn opportunity will come around 4:55 a.m. EDT, or 20 minutes before the engine ignition time. The clouds have cleared over the Cape, with stars now visible again. But the overall weather situation remains dynamic.

0731 GMT (3:31 a.m. EDT)

Meteorologists are carefully monitoring the low clouds over the Cape and the chance for showers to develop within 30 miles of the runway.

0729 GMT (3:29 a.m. EDT)

The final deorbit burn opportunity this morning for landing at Kennedy Space Center would see the orbital maneuvering system engines on the tail of Discovery ignite at 5:15:08 a.m. EDT. The burn would last three minutes and eight seconds, slowing the shuttle by over 300 feet per second to slip from orbit for the hour-long fall back to Earth. Landing on Runway 15 would occur a few seconds before 6:22 a.m. EDT.

0716 GMT (3:16 a.m. EDT)

LANDING DELAYED. Low clouds that could hamper commander Eileen Collins' view of the runway on final approach have forced a delay in this morning's landing. The shuttle will circle the Earth one more time and target a deorbit burn at 5:15 a.m. for landing on the Kennedy Space Center three-mile runway at 6:22 a.m. EDT.

0715 GMT (3:15 a.m. EDT)

Weather evaluations are still being made. The astronauts, meanwhile, are closing Discovery's vent doors in preparation for entry.

0709 GMT (3:09 a.m. EDT)

Entry flight director LeRoy Cain will be making the final "go/no go" decision for the deorbit burn in the next few minutes. He is receiving another weather update from meteorologists in Houston on the observed and forecast conditions at Kennedy Space Center. Also, chief NASA astronaut Kent Rominger continues to fly weather reconnaissance around the runway in the Shuttle Training Aircraft to gauge unexpected low clouds that have formed in the area.

0659 GMT (2:59 a.m. EDT)

Pilot Jim Kelly has completed the auxiliary power unit prestart, which positions switches in the cockpit in the ready-to-start configuration. One of the three APUs will be started just prior to the deorbit burn.

0651 GMT (2:51 a.m. EDT)

The official landing forecast is now calling for a broken deck of clouds at 1,000 feet, which would violate weather rules. The crew has been told to press ahead with entry preparations in case the conditions improve in time for the first deorbit burn opportunity at 3:40 a.m. If weather is deemed "no go" for this entry opportunity, Discovery would make another orbit of Earth and target a deorbit burn 5:15 a.m. for landing at 6:22 a.m.

0649 GMT (2:49 a.m. EDT)

A low cloud deck over Kennedy Space Center has become the main concern for this first of two landing opportunities this morning.

0640 GMT (2:40 a.m. EDT)

Now 60 minutes till the deorbit burn to brake from space. The final "go/no go" decision to begin the entry is about 40 minutes away.

0636 GMT (2:36 a.m. EDT)

The astronauts have been given a "go" for their fluid loading protocol of drinking large amounts of fluids to assist in the readaptation to Earth's gravity.

0635 GMT (2:35 a.m. EDT)

Flight controllers just told the astronauts that some showers have popped up within 30 miles of the runway, which would be a constraint to entry. Also, some clouds between 700 and 1,000 feet have been noted over the Cape. However, meteorologists continue to remain optimistic the conditions will clear in time for the deorbit burn to allow Discovery's descent from space for landing on time at 4:47 a.m. this morning.

0618 GMT (2:18 a.m. EDT)

Commander Eileen Collins just radioed that the myriad of switches in the cockpit are verified set in the correct positions.

0559 GMT (1:59 a.m. EDT)

At this point in the deorbit preparation timeline, the astronauts are scheduled to conduct a review of procedures amongst themselves one final time before entry. They will begin donning their orange launch and landing partial pressure suits a quarter-hour from now.

0545 GMT (1:45 a.m. EDT)

CAPCOM Ken Ham has given the crew an update on the deorbit burn ignition time and firing duration. The burn now starts at 3:39:42 a.m. and should last three minutes and 9 seconds.

0539 GMT (1:39 a.m. EDT)

Now two hours away from the scheduled three-minute, 12-second firing of Discovery's twin orbital maneuvering system engines to drop from orbit. Landing is still set for Kennedy Space Center's Runway 15 at 4:47 a.m. EDT.

0510 GMT (1:10 a.m. EDT)

Discovery's clam-shell-like payload bay doors have been closed and locked in preparation for today's fiery descent into Earth's atmosphere and landing at Kennedy Space Center.

There are no problems to report this morning. The weather forecast for Florida is optimistic. Touchdown is expected a few seconds before 4:47 a.m. EDT.

Also, Mission Control has given the crew a "go" to transition Discovery's onboard computers from the OPS-2 software used during the shuttle's stay in space to OPS-3, which is the software package that governs entry and landing.

And Discovery will soon maneuver to a new orientation in space to improve the communications link with NASA's orbiting data relay satellites.

0505 GMT (1:05 a.m. EDT)

While cruising over the nighttime South Pacific, Discovery's payload bay doors are swinging shut in preparation for today's entry and landing.

0458 GMT (12:58 a.m. EDT)

Mission Control just told the astronauts current observed conditions at the Kennedy Space Center are "go" for landing with a few clouds at 5,000 and 9,000 feet and broken at 22,000 feet with light and variable winds. The official forecast for landing time calls for a few clouds at 2,000 and 10,000 feet and a slight chance of showers within 30 miles primarily over the water. But meteorologists say the possibility of showers could be removed from the forecast soon. The desired runway selection remains Runway 15 -- the northwest to southeast approach.

Given this favorable weather outlook, the "go" has been given for payload bay door closing.

0442 GMT (12:42 a.m. EDT)

Chief NASA astronaut Kent Rominger is flying weather reconnaissance around Kennedy Space Center this morning. He is not reporting any developing fog.

Closure of Discovery's payload bay doors is coming up in about 20 minutes.

0412 GMT (12:12 a.m. EDT)

The astronauts are marching through the deorbit preparations timeline to ready themselves and Discovery for return to Earth about four-and-a-half hours from now. The weather forecast appears favorable for landing time. The slight chance of showers within 30 miles of the runway and ground fog are the only worries at this time.

0330 GMT (11:30 p.m. EDT Sun.)

Here is the latest Mission Control status report:

Discovery's Return to Flight mission is scheduled to conclude with a landing at NASA's Kennedy Space Center early Monday morning.

Discovery has two opportunities to land at the Kennedy Space Center on Monday. The first begins with a 3 minute, 7 second deorbit burn of the Orbital Maneuvering System engines at 3:40 a.m., followed by landing at 4:47 a.m. EDT.

In the event weather prevents landing on that first opportunity, a second is available, with deorbit burn at 5:15 a.m. resulting in a 6:22 a.m. landing. It will be the 15th night landing in Florida and 20th overall for the Space Shuttle Program.

Weather forecasters predict favorable conditions with good visibility and only a slight chance of showers over the water in the vicinity of the three-mile-long landing strip. The backup site at California's Edwards Air Force Base was not activated for Monday.

The crew was awakened at 8:39 p.m. by the song "Come on Eileen" by Dexy's Midnight Runners. It was played for Discovery's Commander Eileen Collins from the Mission Control Team.

Collins, Pilot Jim Kelly and Mission Specialist Steve Robinson, who also serves as Discovery's Flight Engineer, and Mission Specialist Andy Thomas will be on the flight deck for landing. Mission Specialists Soichi Noguchi, Wendy Lawrence and Charlie Camarda will be on Discovery's middeck.

After its departure Saturday, Discovery is now about 200 miles away from the International Space Station and increasing that gap by about 9 miles each time it orbits the Earth. Onboard the Station, Commander Sergei Krikalev and NASA Station Science Officer John Phillips have returned to their normal schedule, waking up at 2 a.m. Monday.

SUNDAY, AUGUST 7, 2005
1300 GMT (9:00 a.m. EDT)

Shuttle commander Eileen Collins and pilot James Kelly tested Discovery's re-entry systems today while their crewmates packed up for landing Monday at the Kennedy Space Center. With forecasters predicting good weather, entry flight director LeRoy Cain said his team is psyched up and ready for NASA's first shuttle re-entry since Columbia disintegrated over Texas two-and-a-half years ago.

"It's great to be here. We've looked forward to this for a long time, we've looked forward to this mission for a long time, we've had a great test flight, we've learned a lot about the vehicle and as you know, in the past couple of years we've learned a lot about ourselves," Cain told reporters early today.

"There's been a lot of good change. We're looking forward, we're not looking back. The team is in great spirits, we're all very excited and anxious. We will come in and we'll do the job tomorrow just like we'd do on any entry and landing day."

Read our full story.

0315 GMT (11:15 p.m. EDT Sat.)

Here is the latest Mission Control status report:

Discovery's astronauts will begin turning their attention toward coming back to Earth Monday by stowing equipment and verifying operation of the orbiter's flight control surfaces and system. The crew was awakened at 8:39 p.m. EDT by "The One and Only Flower in the World" sung by the Japanese group SMAP. It was played for Mission Specialist Soichi Noguchi of the Japan Aerospace Exploration Agency (JAXA).

Commander Eileen Collins, Pilot Jim Kelly and Mission Specialist Steve Robinson, who also serves as Discovery's Flight Engineer, will checkout the orbiter's flight control system at 11:39 p.m. The three also will test the Reaction Control System with a hot fire of the jets at 12:49 a.m.

In the meantime, Noguchi, along with Mission Specialists Andy Thomas, Wendy Lawrence and Charlie Camarda will put away equipment that has been in use during the mission. Noguchi and Thomas will stow the Ku-band communications antenna at 9:19 a.m.

The entire group will gather on Discovery's flight deck and take a moment to answer questions from reporters at 4:06 a.m.

After its departure Saturday, Discovery is now about 90 miles away from the International Space Station and increasing that gap by about 8 miles each time it orbits the Earth.

Onboard the Station, Commander Sergei Krikalev and NASA Station Science Officer John Phillips are returning to their normal schedule, waking up at 2 a.m. Sunday. They are enjoying a restful weekend after nearly 9 full days of work with the Shuttle crew.

Discovery's crew is scheduled for sleep at 12:39 p.m.

The final press briefing before entry is scheduled for 7:30 a.m.

SATURDAY, AUGUST 6, 2005
0948 GMT (5:48 a.m. EDT)

Discovery is 18,000 feet away from the station and continuing to separate. Aboard the shuttle, the astronauts have just berthed the 50-foot robot arm for the remainder of the mission. The crew will be enjoying some off-duty time starting in the next hour or so.

0906 GMT (5:06 a.m. EDT)

The shuttle Discovery undocked from the international space station early today, wrapping up a successful repair and resupply mission. With pilot James Kelly at the controls, Discovery pulled away directly in front of the lab complex and then flew a loop around the station for a spectacular photo survey. Read our full story.

0905 GMT (5:05 a.m. EDT)

The final separation thruster firing is underway aboard Discovery.

0849 GMT (4:49 a.m. EDT)

The shuttle is now 1,900 feet above the station and departing at about three feet per second. The second departure burn upcoming will increase the separation speed ultimately to eight miles per orbit.

0837 GMT (4:37 a.m. EDT)

The first of two separation maneuvers using Discovery's reaction control system thrusters has been performed. The shuttle is back out in front of the docking port as the flyaround continues smoothly.

0823 GMT (4:23 a.m. EDT)

Discovery is now 446 feet below the station.

0812 GMT (4:12 a.m. EDT)

The shuttle continues its loop around the space station at a distance of 450 feet. Discovery is nearing a point directly behind the station.

0801 GMT (4:01 a.m. EDT)

Discovery is nearing a point about 440 feet directly above the space station.

0751 GMT (3:51 a.m. EDT)

Under the control of pilot Jim Kelly, Discovery has begun maneuvering from a point in front of the station to a point directly above the complex. The shuttle will perform a one-lap flyaround to photograph the station before an engine firing boosts Discovery away from the outpost a little more than an hour from now.

0746 GMT (3:46 a.m. EDT)

The Orbiter Docking System in the payload bay has been powered off.

0741 GMT (3:41 a.m. EDT)

The shuttle is just over 200 feet away from the station, continuing to move out in front of the orbiting outpost.

0733 GMT (3:33 a.m. EDT)

Discovery is now 117 feet from the station, backing away at about 0.2 feet per second. The shuttle is headed to a point about 400 feet away to begin a lap flyaround of the station.

0725 GMT (3:25 a.m. EDT)

The on-time undocking occurred as the station and shuttle flew 223 miles over the Pacific Ocean west of Chile.

0724 GMT (3:24 a.m. EDT)

UNDOCKING! The first space shuttle to visit the international space station in more than two-and-a-half years, delivering much-needed supplies and equipment, has successfully undocked from the outpost. Discovery is departing the station after a nine-day stay, headed for landing at Kennedy Space Center early Monday.

0722 GMT (3:22 a.m. EDT)

About two minutes until undocking. The command has been issued to begin driving open the hooks holding Discovery and station together. Once the hooks and latches are opened, one final command will be sent to undock the shuttle.

0719 GMT (3:19 a.m. EDT)

Five minutes from undocking. 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 Jim Kelly will fire Discovery's thrusters to continue the movement away.

0714 GMT (3:14 a.m. EDT)

All is in readiness for today's undocking of space shuttle Discovery from the international space station about 10 minutes from now. The station's solar arrays have been positioned edge-on to the shuttle to ensure they are no damaged from Discovery's thruster plumes, the shuttle-station stack has been maneuvered to the proper undocking attitude and the docking mechanism in the payload bay has powered up.

0530 GMT (1:30 a.m. EDT)

Here is the latest Mission Control status report:

After more than a week of working together in space, the Space Shuttle Discovery and International Space Station crews bid each other farewell tonight.

Following a crew farewell ceremony at 12:36 a.m. EDT, hatches between the spacecraft were closed at 1:14 a.m., with Discovery's undocking planned for 3:24 a.m. Saturday morning.

"The Air Force Song" was the Shuttle crew wake-up song for the day, played at 10:09 p.m. The song was dedicated to Pilot Jim Kelly, a colonel in the U.S. Air Force, at the request of Commander Eileen Collins. Space Station Expedition 11 crewmates John Phillips and Sergei Krikalev woke 30 minutes later.

After Discovery undocks from the Station, with Kelly at the controls, the Shuttle will fly around the Space Station about 400 feet away to allow the Shuttle crew to take photographs of the complex. The flyaround maneuver will begin at 3:54 a.m., and Discovery's final separation from the Station begins with an engine firing at 5:09 a.m.

The majority of the rest of the day will be free time for Discovery and the Station crew. Discovery's crew, including Collins, Kelly and Mission Specialists Steve Robinson, Soichi Noguchi, Andy Thomas, Wendy Lawrence and Charlie Camarda, is scheduled for sleep at 12:39 p.m. Saturday.

The Station crew, which will soon begin working back toward its normal workday hours, is scheduled to sleep at 2:09 p.m.

FRIDAY, AUGUST 5, 2005

A "tiger team" of NASA and contractor engineers is reviewing the manufacturing history of the shuttle Discovery's external fuel tank to find clues about what might have caused a chunk of foam insulation to pop off during launch July 26. NASA officials said today that foam in the area that pulled away was slightly damaged during the tank's processing, requiring a standard repair for relatively routine cracks and gouges. Read our full story.

1920 GMT (3:20 p.m. EDT)

Discovery's astronauts have gone to bed after a good day in space. The Raffaello cargo module was detached from the space station and returned to the shuttle's payload bay this morning for the ride back to Earth. Also, the shuttle inspection boom was placed back in the orbiter.

The shuttle undocks from the station early Saturday at 3:24 a.m. EDT. The crew will spend Sunday packing equipment and testing Discovery's flight control systems for landing. Touchdown at Kennedy Space Center is targeted for 4:46 a.m. EDT (0846 GMT) Monday.

The path Discovery will follow into the Florida spaceport is illustrated here.

A detailed timeline of the entry, descent and landing events is available here.

0445 GMT (12:45 a.m. EDT)

Here is the latest Mission Control status report:

Now in their eleventh day of the mission and with three successful spacewalks behind them, the STS-114 crew of Space Shuttle Discovery is slated to begin preparations for undocking and the final day with their International Space Station counterparts. Their activities for the day include final equipment transfers, stowage and return of the robotic arm, boom and cargo container to the Shuttle payload bay.

"Anchors Aweigh" was the Shuttle crew wake-up song for the day, played at 10:15 p.m. EDT. The song was dedicated to Mission Specialist Wendy Lawrence at the request of Commander Eileen Collins. Space Station Expedition 11 crewmates John Phillips and Sergei Krikalev woke 30 minutes later.

The first tasks of the day center on preparation of the Raffaello Multi-Purpose Logistics Module (MPLM) for its berthing back into Discovery's cargo bay. That module was removed from Discovery on Flight Day 4, mated to the Station and unloaded. Discovery and the MPLM are now loaded with 7,055 lbs. of unneeded equipment and trash for return to Earth.

Pilot Jim Kelly and Lawrence will operate the Station robotic arm later in the day to move Raffaello from the Station and gently place it back into Discovery's cargo bay at 7:34 a.m. EDT. Then, joined by Mission Specialists Charlie Camarda and Andy Thomas, the four will use the Shuttle arm to return the Orbiter Boom Sensor System to its secured position on the sill of the payload bay for the ride back to Earth.

Throughout the day, the on-orbit team will continue with stowing equipment on Discovery's middeck and configurations for undocking, including Mission Specialists Soichi Noguchi, Steve Robinson and Thomas making final configurations and stowage of the spacesuits.

Both crews are scheduled for sleep at 2:09 p.m. EDT Friday with hatch closing and undocking scheduled early Saturday morning.

THURSDAY, AUGUST 4, 2005
1820 GMT (2:20 p.m. EDT)

NASA's mission management team today ruled out another shuttle repair spacewalk, this one to fix a damaged insulation blanket, saying a detailed analysis showed Discovery's crew can safely return to Earth as is. Read our full story.

1709 GMT (1:09 p.m. EDT)

NO FOURTH SPACEWALK. The Mission Management Team has ruled that the damaged white thermal blanket near the left-hand cockpit window does not pose a safety threat for Discovery's return to Earth. Mission Control just radioed the shuttle crew with the news that a fourth spacewalk will not be necessary to deal with the blanket.

NASA plans a mission status briefing at 3 p.m. EDT to provide more details.

0425 GMT (12:25 a.m. EDT)

Here is the latest Mission Control status report:

After an eventful day supporting the third spacewalk of the mission, a light duty day of transfer activities, special events and time off lies ahead for the Space Shuttle Discovery crew as they begin their tenth day in space.

The seven-member Shuttle crew awoke to the well-known country song "Amarillo by Morning," performed by George Strait, at 11:09 p.m. EDT. Their Station counterparts, the Expedition 11 crew of Commander Sergei Krikalev and Flight Engineer and NASA ISS Science Officer John Phillips, woke up 30 minutes later.

The morning includes an in-flight media interview for Commander Eileen Collins, and Mission Specialists Steve Robinson and Charlie Camarda. Elsewhere on the complex, Pilot Jim Kelly and Mission Specialist Wendy Lawrence will be performing a few robotic arm operations, as they release the Station's Canadarm2 from the Mobile Base System and attach it to the Multi-Purpose Logistics Module (MPLM). That task is being done in preparation for return of the MPLM to Discovery's payload bay.

Midway through the crew day, at about 5:19 a.m. EDT, Japanese Aerospace and Exploration Agency Astronaut Soichi Noguchi and Collins will participate in a special video conference with Japanese Prime Minister Junichiro Koizumi; and Minister of Education, Culture, Sports, Science and Technology Nariaki Nakayama. JAXA Astronaut Dr. Mamoru Mohri and several Japanese students and citizens will also participate in the call.

Later, Robinson, Camarda and Noguchi will continue stowage of equipment and supplies in the MPLM on the Shuttle and Space Station. Phillips and Krikalev will help with that activity as well before all of the crewmembers stop to share a special evening meal together.

About an hour later, at 8:04 a.m. EDT, the joint crews have planned a commemorative in-flight event paying tribute to the STS-107 Columbia crew. That event will air on NASA TV. The remainder of the day will be off-duty time for the Shuttle crew as they prepare for the final days of their mission.

Phillips and Krikalev will spend about two hours configuring the Common Berthing Mechanism for the MPLM removal before ending their workday with routine daily planning conference with ground controllers.

WEDNESDAY, AUGUST 3, 2005
1815 GMT (2:15 p.m. EDT)

With a successful spacewalk repair job today, engineers believe the shuttle Discovery's heat shield is in good shape for re-entry and landing Monday. But one question mark remains: What, if anything, to do about a damaged insulation blanket just below commander Eileen Collins' left cockpit window. Read our full story.

1600 GMT (12:00 p.m. EDT)

Like an anxious mom plucking out splinters, astronaut Stephen Robinson gently pulled two dislodged gap fillers from the shuttle Discovery's belly early today in an unprecedented 223-mile-high repair job. Read our full story.

1451 GMT (10:51 a.m. EDT)

EVA ENDS. Repressurization of the airlock has begun, officially concluding today's successful spacewalk by Soichi Noguchi and Steve Robinson at about 10:49 a.m. EDT for a total duration of 6 hours and 1 minute.

1446 GMT (10:46 a.m. EDT)

A collection of pictures from this morning's gap filler retrieval is posted here.

1439 GMT (10:39 a.m. EDT)

Discovery's outer airlock hatch has been closed.

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

The shuttle's new inspection boom is being used to examine the damaged insulation blanket just below left cockpit window. You can see a close-up image here.

1428 GMT (10:28 a.m. EDT)

The spacewalkers are making their way back into Discovery's airlock in the payload bay.

1348 GMT (9:48 a.m. EDT)

The spacewalk is now passing the five-hour mark. meanwhile, some additional inspections of that damaged thermal blanket below the commander's cockpit window is upcoming using the shuttle's robot arm.

1340 GMT (9:40 a.m. EDT)

The spacewalkers continue their housekeeping work as the EVA nears completion.

1312 GMT (9:12 a.m. EDT)

The astronauts sound giddy after the successful repair job beneath the nose of space shuttle Discovery today. Spacewalker Steve Robinson, perched on the station's robot arm, removed with ease two protruding tile gap fillers that threatened to trigger dangerously high temperatures during the shuttle's fiery reentry.

1306 GMT (9:06 a.m. EDT)

Robinson remains beneath the shuttle, using his camera to shoot unique pictures of the vehicle's tiled belly.

1303 GMT (9:03 a.m. EDT)

The astronauts will be making their way into the clean up chores to put away tools and equipment, wrapping up this third successful spacewalk of Discovery's mission.

1255 GMT (8:55 a.m. EDT)

He's done it! With absolute ease, spacewalker Steve Robinson has gently pulled the second protruding gap filler from Discovery's belly.

1254 GMT (8:54 a.m. EDT)

The arm brakes are active again. Robinson is preparing to pluck out the second and final tile gap filler.

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

Communications between Robinson and arm operator Jim Kelly inside the Destiny lab module are continuing to get the arm positioned over the site of the second gap filler.

1247 GMT (8:47 a.m. EDT)

Robinson has put the gap filler into a trash bag attached to his suit. The arm will move the spacewalker into position to retrieve the second thin gap filler.

1246 GMT (8:46 a.m. EDT)

The station's robotic arm is now backing Robinson away from the shuttle, having removed the first gap filler with his gloved fingers.

1245 GMT (8:45 a.m. EDT)

"I'm pulling and it's coming out very easily," Robinson reports.

1245 GMT (8:45 a.m. EDT)

The arm motion has stopped and the brakes are on.

1244 GMT (8:44 a.m. EDT)

Robinson is giving precise directions of which way to move the arm to get into a good position for pulling out the first of two protruding gap fillers.

1243 GMT (8:43 a.m. EDT)

The arm is inching Robinson ever closer to reach the gap filler for this unprecedented and ultra-delicate job.

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

"Stand tall and lean forward," robot arm operator Jim Kelly is telling spacewalker Steve Robinson.

1239 GMT (8:39 a.m. EDT)

The station arm is moving Robinson up close and personal with the shuttle tiles.

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

Robinson remains en route to the first gap filler site on the port-side. He'll try pulling the gap filler with his fingers as the first course of action.

1219 GMT (8:19 a.m. EDT)

The station's robot arm is in motion now, ferrying Robinson away from the station's lab module area where he climbed aboard arm and configured his tools.

1218 GMT (8:18 a.m. EDT)

Mission Control has given the crew a "go" to proceed under Discovery for the gap filler work.

1214 GMT (8:14 a.m. EDT)

Noguchi is helping Robinson get ready for the never-before-attempted job of going under the shuttle for repair work. The spacewalkers are being extra cautious about tools dangling from Robinson's spacesuit that could bump the shuttle when the astronaut is within reach of the orbiter tiles.

1208 GMT (8:08 a.m. EDT)

Robinson has climbed into a foot platform attached to the end of the space station arm for the ride beneath Discovery.

1158 GMT (7:58 a.m. EDT)

Astronaut Steve Robinson will be perched on the end of the space station's robot arm to remove two protruding gap fillers from the underside of Discovery. The shuttle arm, extended by the observation boom, will use its cameras to monitor the work. You can see computer generated views of the spacewalk by clicking here.

1148 GMT (7:48 a.m. EDT)

Now three hours into the spacewalk.

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

Robinson is gathering the absolute essential tools -- no more and no less -- needed for the gap filler removal. He doesn't want to take too much beneath the orbiter and increase the risk of something banging into the heat-protection tiles. For more on the gap fillers and why they need to be cleared away, see our full story.

1133 GMT (7:33 a.m. EDT)

The relocation of the space station's Canadian-built robotic arm has been completed. The arm has an inch-worm capability to switch bases of operation. Earlier this morning the arm was anchored on the Destiny lab module with the free end being used to install the External Stowage Platform-2. Now, that once-free end has attached itself to the Mobile Base System on the S0 truss, becoming the arm's anchor. The other end has detached from Destiny, becoming the free end for use in positioning Steve Robinson under Discovery to remove the gap fillers a little while from now.

1127 GMT (7:27 a.m. EDT)

Robinson has removed and stowed the grapple fixture from the external platform for return to Earth. Noguchi has finished his work with MISSE-5 and started making his way down the P6 truss.

1109 GMT (7:09 a.m. EDT)

With MISSE-5 mounted to the station near the top of the P6 truss, Noguchi has opened the package to expose the materials to space.

1105 GMT (7:05 a.m. EDT)

Japanese astronaut Soichi Noguchi has climbed 60 feet above Discovery's payload bay to the space station's P6 solar array truss where he will attach an external experiment. The Materials International Space Station Experiment-5 (MISSE-5) is a suitcase-like package to be opened inside out, revealing a host of material samples to the space environment for extended exposure.

The astronauts retrieved the MISSE-1 and -2 packages during an earlier spacewalk on Discovery's mission for return to scientists on Earth. Those experiments had been outside the station since July 2001.

From a NASA news release:

"It's always exciting to see the things that come back down from space," said William Kinard, MISSE chief scientist. "There are always surprises. The real value and benefit in these experiments is seeing what you didn't originally expect."

The only way to test how different materials will perform in space is to test them in that environment. Laboratories can simulate just one or two space environmental factors at a time. The research from MISSE will provide the insight needed to develop materials for future spacecraft and will also help researchers make materials and coatings that will last longer on Earth.

Once MISSEs 1 and 2 are brought back to Earth, they will be returned to NASA's Langley Research Center, Hampton, Va., where they will be opened and studied in a clean room by the project's principal investigators. After this initial examination, the materials will be transferred to the NASA centers from which they originated.

The Langley Research Center manages the MISSE project. Other partners include NASA's Glenn Research Center, Cleveland; Goddard Space Flight Center, Greenbelt, Md.; Jet Propulsion Laboratory, Pasadena, Calif.; Johnson Space Center, Houston; and Marshall Space Flight Center, Huntsville, Ala.

Industry partners include the Boeing Company, Chicago; Hughes Aircraft Company, Torrance, Calif.; Lockheed Martin, Bethesda, Md.; Loral, Seabrook, Md.; Rockwell International, Richardson, Texas; and TRW, Redondo Beach, Calif.

Department of Defense partners are Aerospace Corporation, El Segundo, Calif.; Air Force Office of Scientific Research, Arlington, Va.; and Air Force Research Lab, Dayton, Ohio.

1058 GMT (6:58 a.m. EDT)

Flight controllers are looking at shuffling the spacewalk timeline. The relocation of the station arm for use in the gap filler work is going quicker than expected. So the gap filler removal could happen sooner rather than later, and other work slated for the middle of the spacewalk shifted to the EVA's end.

1048 GMT (6:48 a.m. EDT)

As the spacewalk reaches the two-hour mark, Robinson is working to remove the robot arm grapple fixture on the External Stowage Platform-2. The fixture will be returned to Earth for use on a future station component. Meanwhile, Noguchi is preparing to deploy a suitcase-like materials exposure package on the station's exterior.

1033 GMT (6:33 a.m. EDT)

Robinson is connecting cabling to provide power and heating to the platform.

1027 GMT (6:27 a.m. EDT)

The station's robot arm is releasing the newly-installed platform. The arm will be repositioned in advance of its use later in the spacewalk to reach the tile gap filler areas on the underside of Discovery.

1017 GMT (6:17 a.m. EDT)

The alignment appears fixed and the spacewalkers are again driving the locking mechanisms to bolt the platform and station together.

1005 GMT (6:05 a.m. EDT)

The spacewalkers are reporting some trouble tightening the locking bars due to misalignment. They will release the capture claw slightly in hopes of getting a better alignment.

0948 GMT (5:48 a.m. EDT)

Now one hour into today's EVA. The spacewalkers are tightening the capture claw and latching bolts and preparing to route cabling to the newly-installed platform.

0942 GMT (5:42 a.m. EDT)

The capture claw is closing, firmly joining the External Stowage Platform-2 to the international space station.

0940 GMT (5:40 a.m. EDT)

"Ready-to-latch" indicators have been achieved as the platform reaches its attachment point.

0935 GMT (5:35 a.m. EDT)

This is the 61st spacewalk devoted to station assembly and maintenance and the third for Robinson and Noguchi, who logged 14 hours and four minutes of spacewalk time in two previous excursions. The cumulative total for the previous 60 spacewalks is 362 hours and 19 minutes by 53 astronauts and cosmonauts.

The primary goals of today's planned seven-hour excursion are to attach a massive external tool box to the space station's Quest airlock module; to mount an experiment package on the top of the station's solar array truss; and to remove two "gap fillers" sticking up between heat shield tiles on Discovery's belly.

The impromptu repair job was added to today's spacewalk because of uncertainty over what sort of damage might result if the gap fillers were left in place for re-entry. The concern was that the gap fillers, sticking up into the hypersonic wind flow across the belly of the shuttle, could trigger an early onset of turbulence that would result in higher downstream heating.

Read our preview story.

0933 GMT (5:33 a.m. EDT)

With the spacewalkers watching first-hand, Discovery astronauts Jim Kelly and Wendy Lawrence are operating the space station's robotic arm carrying the External Stowage Platform-2 from inside the Destiny lab module. The arm is beginning to move the platform within inches of its installation point.

0915 GMT (5:15 a.m. EDT)

The spacewalkers are getting into position to assist with installation of the External Stowage Platform-2, which will hold spare parts and replacement units for the outpost. They've climbed from the shuttle airlock in the payload bay, up the side of the station's Destiny laboratory module and over to the Quest airlock module where the platform will be mounted.

"The External Stowage Platform -- now that's the kind of thing I really wish I had on my house -- is kind of a combination of a back porch and a garage, both at once," Steve Robinson said in a pre-flight interview.

"It's a flat platform that sticks out from the airlock on the space station, and of course being in space you can use both sides of it, not just one side -- now that would really be handy at home. But it's a place to keep spare parts, and it's got power. Any electrical instrument up there is going to need to be protected from the cold, so it needs heaters, so it needs power. This will be kind of a grid type of platform.

"The way we put it on is we have kind of a big adapter plate that I put on while I'm attached to the arm. I just hold it, attach it to the space station, bolt it on by hand, and that gives the External Stowage Platform a nice home to berth on. That's done with the robot arm while Soichi and I kind of watch and guide things. And then we cable it up ourselves. We each have a big, long cable that we route from one part of the space station onto the stowage platform. And then it should be ready for operation."

0852 GMT (4:52 a.m. EDT)

EVA BEGINS. Space shuttle Discovery astronauts Soichi Noguchi and Steve Robinson put their spacewalking suits on internal battery power at 4:48 a.m. EDT, marking the official start time for this third EVA of the mission. This 7-hour excursion will mount a stowage platform to the space station's hull, deploy an experiments package and culminate later today with retrieval of tile gap fillers on the belly of Discovery.

The two men will be floating out of the airlock in the next few minutes to begin gathering tools and equipment needed. The first major task on the timeline is installing the External Stowage Platform-2 to the space station's exterior.

0847 GMT (4:47 a.m. EDT)

Discovery's airlock has been depressurized in preparation for the start of this morning's spacewalk. All activities are going well and the EVA should be getting underway shortly.

0500 GMT (1:00 a.m. EDT)

Here is the latest Mission Control status report:

The Space Shuttle Discovery crew begins their ninth day in space with preparations for the third spacewalk of the mission. This extravehicular activity (EVA) was a preplanned activity for the mission, but now includes a new task -- repair of two protruding gap fillers between tiles on the bottom the Shuttle.

The crew began the day waking up at 11:09 p.m. EDT to "Where My Heart Will Take Me," the theme song from Star Trek: Enterprise. The song, composed by Dennis McCarthy, was selected for the crew as a surprise dedication from the Deputy Shuttle Program Manager Wayne Hale. The International Space Station Expedition 11 crew of Sergei Krikalev and John Phillips woke 30 minutes later.

Mission Specialists Steve Robinson and Soichi Noguchi are scheduled to begin their third spacewalk at 4:14 a.m. EDT as they exit out of the Space Shuttle airlock. The two will be assisted by Andy Thomas, serving as the intravehicular officer overseeing the spacewalk from inside, as well as Pilot Jim Kelly and Mission Specialists Wendy Lawrence and Charlie Camarda who will be supporting various robotic arm activities throughout the day.

The spacewalk is scheduled to last about 7 hours. The first task entails Kelly and Lawrence maneuvering the External Stowage Platform-2 (ESP-2), via the Station's robotic arm, which they pulled from Discovery's payload bay earlier today, onto the Station. As the ESP-2 reaches its final position, Robinson and Noguchi will guide the structure and secure it into place. With that task complete, Lawrence and Kelly will conduct a "walk off" maneuver of the Station robotic arm, by attaching the "free" end to the Mobile Base System and releasing the other end from the Destiny Laboratory module to where it will be needed as a platform for Robinson later in the EVA.

The two spacewalkers will move on to individual tasks, with Noguchi installing the Materials International Space Station Experiment-5 (MISSE-5), a materials experiment that will study the degradation of solar cell samples in the space environment. He'll then remove the Rotary Joint Motor Controller from the Space Station truss before proceeding to a support position to assist Robinson in his final tasks.

Meanwhile, Kelly will work with Camarda, using the Orbiter Boom Sensor System to inspect repair demonstration tiles inside the Shuttle's payload bay. Later, Camarda will also work with Krikalev and Phillips to continue stowing supplies and equipment inside Discovery and the Station. Discovery Commander Eileen Collins will monitor and supervise all the activities.

Robinson, now attached to the Station robotic arm, will attempt to repair two tile gap filler protrusions located on the underside of Discovery. He will first try to gently pull out the protruding material, and if need be, remove by trimming with a hacksaw.

Gap fillers are used in areas to restrict the flow of hot gas into the gaps between Thermal Protection System components. They consist of a layer of coated Nextel fabric and are normally about 0.020-inch thick. These protrusions were identified from photos taken during the rendezvous pitch maneuver conducted on flight day three, as Discovery approached the orbiting Space Station.

The crews are scheduled to go to sleep about 3:09 p.m. EDT.

TUESDAY, AUGUST 2, 2005

Amid planning for an unprecedented shuttle heat-shield repair spacewalk Wednesday, engineers also are assessing the potential threat posed by a damaged insulation blanket just below commander Eileen Collins' left cockpit window. While engineers say the blanket poses no threat of heat damage during entry, there's a chance a small portion of the blanket could rip away in the lower, denser atmosphere and hit the shuttle's aft section. Read our full story.

1930 GMT (3:30 p.m. EDT)

The Discovery astronauts said Tuesday they were initially concerned about the safety of a proposed spacewalk repair job Wednesday to remove two protruding "gap fillers" sticking out from heat-shield tiles on the shuttle's belly. But they are now convinced it's not only safe, but a relatively simple task that will eliminate any lingering concern about unwanted re-entry heating. Read our full story.

1520 GMT (11:20 a.m. EDT)

President George W. Bush phoned the Discovery and space station astronauts this morning, speaking with commander Eileen Collins.

THE PRESIDENT: Commander Collins, can you hear me?

COLLINS: Yes, sir, we hear you loud and clear. Good morning.

THE PRESIDENT: Good morning. Thank you for taking my phone call. I just wanted to tell you all how proud the American people are of our astronauts. I want to thank you for being risk-takers for the sake of exploration. I want to welcome our Japanese and Australian and Russian friends. And I wish you Godspeed in your mission. I know you've got very important work to do ahead of you. We look forward to seeing the successful completion of this mission. And, obviously, as you prepare to come back, a lot of Americans will be praying for a safe return.

So it's great talking to you. Thanks for being such great examples of courage for a lot of our fellow citizens.

COLLINS: Thank you very much, Mr. President. We want to tell you that we really enjoy what we're doing, we really believe in our mission, and we believe in space exploration and getting people off the planet and seeing what's out there. So the steps that we're taking right now are really worth it, and we want everybody to know that. And thank you very much for taking the time out of your busy schedule to talk to us.

THE PRESIDENT: Well, listen, I want to thank you, Commander, and thank your fellow astronauts there. I agree with you -- I think what you're doing is really important. And you've got a strong supporter for your mission here in the White House. I will tell you Laura went down and watched the launch in Florida, with my little brother, Jeb, and came back all excited about the energy that -- there on the East Coast of Florida. But we're with you, and wish you all the very best. Thanks for taking my phone call. Now get back to work.

COLLINS: Thank you very much, sir. We did fly over Texas today and had a good look at it. It was beautiful. Have a good day.

THE PRESIDENT: Thank you. (Laughter.)

0535 GMT (1:35 a.m. EDT)

Here is the latest Mission Control status report:

The Space Shuttle Discovery and International Space Station crews will continue transferring equipment and supplies between the two vehicles today. They will also review updated tasks for the third planned spacewalk of the mission.

Discovery's crew was awakened at 11:09 p.m. EDT by the song "Big Rock Candy Mountain," by Harry McClintock for Mission Specialist Andy Thomas. The Space Station crew was awakened at 11:39 p.m. EDT by a tone onboard.

Mission managers decided to remove two gap fillers that are protruding from areas between heat-shielding tile on the Shuttle's underbelly. It is a relatively simple process that can be accomplished as an add-on task to Wednesday's spacewalk.

During the spacewalk, Mission Specialist Steve Robinson will venture under the Space Shuttle on the tip of the Station's robotic arm, locate the protrusions and gently tug until they come out. If that does not work, Robinson will have tools to cut off the protrusions.

Robinson, fellow spacewalker Soichi Noguchi and spacewalk choreographer Andy Thomas will spend time Tuesday assembling a hack saw for the removal job and reviewing the new procedure.

All of the Shuttle and Station crewmembers will participate in a news conference at 5:59 a.m. EDT. Krikalev and Phillips will be interviewed by reporters at Mission Control Moscow at 6:45 a.m. EDT. It will be replayed with translation on NASA TV at 7:15 a.m. EDT.

At 7:39 a.m. EDT Discovery Pilot Jim Kelly and Mission Specialist Wendy Lawrence will grapple the External Stowage Platform-2 (ESP-2) and unberth it from Discovery's payload bay. This is in preparation for the hardware's installation at the beginning of Wednesday's spacewalk. Preparing the ESP-2 Tuesday provides the extra time for the tile gap filler task during the spacewalk.

Before the Shuttle and Station crews go to sleep, the hatch will be closed between the two vehicles and the Shuttle's cabin will be depressurized to 10.2 psi on the eve of the last spacewalk. The crews are scheduled to go to sleep about 3:09 p.m. EDT.

MONDAY, AUGUST 1, 2005

A Discovery astronaut, working on the end of the space station's robot arm, will attempt to remove two protruding "gap fillers" sticking up from protective heat-shield tiles on the belly of the shuttle Discovery Wednesday during an already planned spacewalk, officials said today. Read our full story.

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

NASA engineers are refining plans for an unprecedented but relatively straight forward spacewalk repair job Wednesday to remove two protruding "gap fillers" from the shuttle Discovery's underside heat shield tiles. While no spacewalking astronaut has ever been asked to work under the shuttle, out of direct view, engineers say the gap filler fix is not technically difficult or especially risky. Read our full story.

1559 GMT (11:59 a.m. EDT)

EVA ENDS. Soichi Noguchi and Steve Robinson completed today's successful spacewalk at 11:56 a.m. EDT for a duration of 7 hours and 14 minutes.

The two spacewalkers installed a new motion control gyroscope on the international space station today, but initial electrical checks failed. Japanese astronaut Soichi Noguchi then was asked to disconnect and reseat three critical electrical cables and, after finding one that was a bit loose, the gyroscope powered up normally. Read our full story.

1425 GMT (10:25 a.m. EDT)

The spacewalkers are completing some get-ahead tasks before they head back to the airlock. The primary job -- replacing the gyroscope -- went well this morning.

1352 GMT (9:52 a.m. EDT)

Mission control in Houston has confirmed that the new gyroscope is successfully installed and powered. It will take over six hours for the gyro's internal mechanism to spin up to 6,600 rpm.

The first attempt to activate the gyro didn't work because of a loose power connector. Soichi Noguchi found the problem and re-seated the connector.

1255 GMT (8:55 a.m. EDT)

The International Space Station has been fitted with a replacement control-stabilizing gyroscope by the spacewalkers.

1130 GMT (7:30 a.m. EDT)

The spacewalkers have removed the new gyro from its launch platform in rear of space shuttle Discovery's payload bay. The unit is being set aside so that the failed gyro can be locked into the carrier platform for return to Earth. Once that is complete in the next few minutes, the astronauts will take the new device up to the station for installation. Everything continues to go smoothly in today's EVA.

1025 GMT (6:25 a.m. EDT)

Perched on the end of the space station's robot arm, Soichi Noguchi is carrying the 600-pound failed control gyroscope to the payload bay of shuttle Discovery. The spacewalkers unhooked electrical cables and unbolted the device a short time ago, allowing the astronauts to pull the gyro from the Z1 truss location. Once in the payload bay, the old unit will be temporarily stowed while the new gyro is lifted from the launch carrier.

0930 GMT (5:30 a.m. EDT)

Floating in the shuttle Discovery's airlock, astronauts Stephen Robinson and Soichi Noguchi switched their spacesuits to internal battery power at 4:42 a.m. EDT to officially begin a high-priority spacewalk to replace one of the international space station's gyroscopes.

"All right! Let's get started," said Robinson as the two headed out into the shuttle's cargo bay.

This is the 60th spacewalk devoted to space station assembly and maintenance by 40 U.S. astronauts, 10 Russian cosmonauts, one Frenchman, one Canadian and one Japanese (Noguchi). Going into today's excursion, station spacewalk time totaled 355 hours and five minutes.

Read our full story.

0845 GMT (4:45 a.m. EDT)

EVA BEGINS. Soichi Noguchi and Steve Robinson switched their suits to internal battery power at 4:42 a.m. EDT, marking the spacewalk's official start time for this EVA.

0430 GMT (12:30 a.m. EDT)

Here is the latest Mission Control status report:

Now spacewalk veterans, Astronauts Soichi Noguchi and Steve Robinson will step outside for the second of three planned spacewalks today at 4:14 a.m. EDT. The sole objective of the 6 1/2-hour excursion is to replace a failed International Space Station attitude control gyroscope.

The pair will have about an hour of setup time after exiting Space Shuttle Discovery's airlock and positioning themselves at the Station's Z1 truss segment. Mission Control will shut down the failed Control Moment Gyroscope 1 (CMG1) about 5:09 a.m. EDT and then give a go for the spacewalkers to start removing it about 15 minutes later. Mission Specialist Andy Thomas will choreograph the activities from inside and relay information from Mission Control to the spacewalkers.

Noguchi will take the failed CMG to Discovery's cargo bay while riding the Station's robot arm. He will temporarily store it until the new gyro is removed and the old one can be placed in its carrier with Robinson's help. Noguchi will then carry the new gyro at the end of the robot arm to the Z1 truss. Discovery Pilot Jim Kelly and Mission Specialist Wendy Lawrence will operate Canadarm2 for the spacewalk.

After it is installed, Station flight controllers will power up and check out the new gyroscope about 9:14 a.m. EDT and start it up at 9:39 a.m. EDT. With CMG1 replaced, the full complement of four gyroscopes will be available for Station operations. CMG2 has operated well since the spacewalkers restored power to it in the first spacewalk Saturday.

Inside the orbiting complex, Station residents Sergei Krikalev and John Phillips and Discovery Commander Eileen Collins and Mission Specialist Charlie Camarda will continue transferring equipment and supplies between the two vehicles. Collins will focus on collecting byproduct water from Discovery's power generation system for transfer to Station.

Discovery's crew was awakened at 11:09 p.m. EDT by the song "Walk of Life," by Dire Straits for Robinson. The Space Station crew was awakened at 11:39 p.m. EDT by a tone onboard.

The crews of Discovery and the Space Station are scheduled to go to sleep about 3:09 p.m. EDT.

SUNDAY, JULY 31, 2005

Engineers are considering what, if anything, to do about two protruding "gap fillers" on the belly of the space shuttle Discovery that could trigger increased re-entry turbulence and localized, potentially dangerous, heating if they are left as is. Read our full story.

0500 GMT (1:00 a.m. EDT)

Here is the latest Mission Control status report:

Transfers of additional water and supplies to the International Space Station will continue Sunday as the crew aboard Space Shuttle Discovery begins Flight Day 6. The STS-114 mission was formally extended by one day as mission managers Saturday decided to spend one more day docked to the ISS. Two additional collapsible water containers holding more than 10 gallons each are expected to be added to the cargo transfer list before the Shuttle leaves, bringing to 17 the number that will be left behind, a substantial increase in the amount of available water.

ISS Program Manager Bill Gerstenmaier said in a Saturday news conference that the program was very happy to have the additional supplies and that the station's consumables status had improved considerably with Discovery's visit.

Mission Manager Wayne Hale said Saturday that the added mission day will be added to the crew's schedule after the third spacewalk day.

Hale also noted Saturday that Discovery's protective tiles and thermal blankets passed review and are cleared for entry. Analysis continues on the reinforced carbon-carbon areas and two protruding gap fillers.

Also Sunday, astronauts will make preparations for the second spacewalk of the mission scheduled for Monday. Discovery's cabin pressure will be reduced to 10.2 psi to prepare Mission Specialists Stephen Robinson and Soichi Noguchi of the Japan Aerospace Exploration Agency for their work outside the spacecraft.

Space Shuttle and Space Station crewmembers will participate in two separate in-flight interviews. Shuttle Commander Eileen Collins, Pilot Jim Kelly and Mission Specialist Charlie Camarda will talk to reporters with ABC News, Fox News and NBC's "Meet the Press" at 6:49 a.m. EDT. Collins, Robinson, Noguchi and NASA ISS Science Officer John Phillips will speak with CBS News, CNN and Discovery Channel reporters at 8:39 a.m.

Discovery's crew was awakened at 12:11 a.m. EDT by the song "I'm Goin' Up," by Claire Lynch for Mission Specialist Wendy Lawrence. The Space Station crew was awakened about the same time by a tone onboard.

The crews of Discovery and the Space Station are scheduled to go to sleep about 3:09 p.m. EDT.

SATURDAY, JULY 30, 2005

NASA's mission management team today extended the shuttle Discovery's flight by one day, giving the astronauts more time to assist and resupply the international space station's two-man crew, and concluded the shuttle's heat-shield tiles and insulation blankets are fit for a normal re-entry Aug. 8. Read our full story.

SATURDAY, JULY 30, 2005

Astronauts Stephen Robinson and Soichi Noguchi wrapped up a smooth spacewalk today, testing heat-shield repair techniques, hot wiring one of the space station's gyroscopes and mounting an attachment device that later will hold a large external tool kit and spare parts box. Read our full story.

1636 GMT (12:36 p.m. EDT)

EVA ENDS. Repressurization of Discovery's airlock started at 12:36 p.m. EDT, marking the official completion time of this first of three spacewalks of the shuttle mission. The EVA lasted 6 hours and 50 minutes.

1604 GMT (12:04 p.m. EDT)

The spacewalkers are making their way back into the airlock to wrap up today's successful EVA.

1515 GMT (11:15 a.m. EDT)

Today's spacewalk continues to progress smoothly. The GPS antenna replacement and the control moment gyro re-wiring task have been completed, along with a late-added job of retrieving an experiment package mounted on the station's hull.

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

The ESPAD structure has been mated to the station by the spacewalkers.

1300 GMT (9:00 a.m. EDT)

The next spacewalk task now underway is installation of the External Stowage Platform-2 Attachment Device (ESPAD) on the space station. The ESPAD structure and associated cabling are being mounted to the exterior of the Quest airlock module, a preparatory step so that the ESP-2 can be installed on top during this mission's third spacewalk late next week.

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

Working the shuttle Discovery's cargo bay, astronauts Stephen Robinson and Soichi Noguchi tested potential heat-shield repair techniques today, a major milestone in NASA's recovery from the Columbia disaster. Read our full story.

1115 GMT (7:15 a.m. EDT)

The spacewalkers are in the back of the shuttle payload bay where damaged the tile/RCC panel repair demonstrations are being performed.

1000 GMT (6:00 a.m. EDT)

Astronauts Stephen Robinson and Soichi Noguchi began a planned six-and-a-half hour spacewalk today, a busy excursion highlighted by long-awaited tests of rudimentary tile and wing leading edge repair techniques that were developed in the wake of the Columbia disaster. Read our full story.

0946 GMT (5:46 a.m. EDT)

EVA BEGINS. Soichi Noguchi and Steve Robinson switched their suits to internal battery power at 5:46 a.m. EDT, marking the spacewalk's official start time for this planned 6.5-hour EVA.

0940 GMT (5:40 a.m. EDT)

Depressurization of the airlock is nearing completion.

0820 GMT (4:20 a.m. EDT)

Mission Control says the start of the EVA has been pushed back about an hour because spacewalk preparations for Soichi Noguchi and Steve Robinson aboard Discovery are running behind schedule.

0515 GMT (1:15 a.m. EDT)

Here is the latest Mission Control status report:

Astronauts Soichi Noguchi and Steve Robinson will step outside for their first spacewalk, and the first of this mission, early Saturday. The six and a half hour spacewalk is scheduled to begin from Discovery's airlock at 4:44 a.m. EDT.

Discovery's crew was awakened at 11:43 p.m. EDT by the Japanese song "Sanpo," sung by a group of children, including Noguchi's. The Station crew was awakened at 12:09 a.m. EDT by a tone onboard. Noguchi and Robinson's spacewalk preparations, including a pure oxygen pre-breathe and exercise procedure, will get underway at 1:39 a.m., with Intravehicular (IV) crewmember Andy Thomas' assistance. The procedure will purge the spacewalkers' blood of nitrogen to prevent the painful symptoms of "the bends" while wearing their low-pressure spacesuits.

About the same time, Station Commander Sergei Krikalev and NASA Science Officer John Phillips will maneuver the Station's robotic arm into a position to support the spacewalk. At 1:55 a.m. the pair will "walk off" Canadarm2 from the Mobile Base System to the Destiny lab and change its operating base. The arm will be operated by Shuttle Pilot Jim Kelly and Mission Specialist Wendy Lawrence during the spacewalk to help install the External Stowage Platform-2 (ESP-2) Attachment Device (ESPAD) onto Station.

After the excursion begins and the spacewalkers have completed about an hour of tool setup, the first task is to test thermal protection system repair techniques. Noguchi and Robinson will work side-by-side in Discovery's cargo bay at a pallet of purposely damaged orbiter heat shield samples. They will practice the Emittance Wash Applicator (EWA) repair of tile samples and the NOAX (Non-Oxide Adhesive eXperimental) repair of Reinforced Carbon-Carbon samples.

After the testing is complete, the pair will move on to their Station assembly tasks. They will install the ESPAD and associated cabling on the Station's Quest airlock so that the ESP-2 can be installed on top during the third spacewalk.

Next, Noguchi will replace a Global Positioning System (GPS) antenna on the Station's truss structure. At the same time, Robinson will retrieve tools for the second spacewalk's Control Moment Gyroscope-1 replacement and swap connectors to restore power to the Station's CMG-2. The last job will be for both crewmembers to route cabling for the ESP-2 installation on the third spacewalk.

Once the spacewalk has begun and the Station's airlock's hatch is opened as an emergency door, the hatches between Discovery and Station will be re-opened so the crews can work together to support the spacewalk and continue transfer work. Commander Eileen Collins, Mission Specialist Charlie Camarda, Krikalev, Phillips and Lawrence will continue transferring water and other equipment to the Station from Discovery and the Raffaello cargo module. The hatches will be closed before the end of the spacewalk again to allow the crew to re-enter the Shuttle airlock. Once the crew is inside and the Shuttle's airlock is repressurized, the hatches will be re-opened.

At 9:09 a.m., Kelly and Camarda are scheduled to perform additional surveys of Discovery's wing leading edge Reinforced Carbon-Carbon with the Shuttle arm and Orbiter Boom Sensor System. They will use the sensors to focus on seven areas of interest along the port wing.

The crews of Discovery and the Station are scheduled to go to sleep about 3:39 p.m.

FRIDAY, JULY 29, 2005

NASA Administrator Michael Griffin mounted a spirited defense of the shuttle program and the beleaguered external tank project Friday, saying virtually all of NASA's post-Columbia improvements to the huge tank worked as expected during Discovery's launching Tuesday. He said the space agency was not yet ready to rule out another shuttle flight before the end of the year. Read our full story.

1540 GMT (11:40 a.m. EDT)

NASA now says there were six target areas on Discovery being inspected with the boom today vs. the 11 the agency said earlier.

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

Discovery's astronauts have put the inspection boom back into action this morning, using the sensor/camera package to examine almost a dozen target sites on the shuttle's underside and wing leading edges. Although none of the areas are overly worrisome, engineers wanted a bit more data on the orbiter's thermal protection system.

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

The shuttle Discovery's crew was surprised and disappointed to learn about foam insulation falling off their ship's external tank during launch. Commander Eileen Collins said today the shuttle program should remain grounded until the problem is fixed, but she said talk of retiring the winged spaceplanes is premature. Read our full story.

0830 GMT (4:30 a.m. EDT)

The Italian-built Raffaello cargo-carrying module was lifted from Discovery's payload bay by the space station's robotic arm this morning. The arm maneuvered the barrel-shaped module and successfully mounted it to the station for unloading. The astronauts will open Raffaello later today to begin unloading the tons of equipment and supplies. The module will be put back into Discovery next week for return to Earth.

0425 GMT (12:25 a.m. EDT)

Here is the latest Mission Control status report:

The first full day of joint Space Shuttle and International Space Station operations will be highlighted by installation of a cargo transportation module, additional orbiter heat shield inspections and spacewalk preparations.

Discovery's crew was awakened at 11:39 p.m. EDT by the song "Vertigo" by U2 played for Pilot Jim Kelly. Capcom Shannon Lucid noted during the wakeup call that Kelly, whose nickname is "Vegas," was promoted to Colonel in the U.S. Air Force recently. The Station crew was awakened at 12:09 a.m. EDT by a tone onboard.

In this upcoming flight day, Mission Specialist Wendy Lawrence and Kelly will guide the Station's robot arm, Canadarm2, to pluck the Multi Purpose Logistics Module from Discovery's cargo bay and install it on the Station. The MPLM, called Raffaello, will be attached to the Station's Unity module. While the crew was asleep, the Station flight control team verified Unity's attach mechanism is ready for the addition.

Kelly and Station Flight Engineer John Phillips will walk Canadarm2 off of the Destiny lab beginning at 5:39 a.m. EDT, onto the Mobile Base System for situational awareness views from its cameras for the survey. Mission Specialist Charlie Camarda and Kelly will begin additional focused inspections of Discovery's heat shield using the Shuttle arm and Orbiter Boom Sensor System shortly after 6 a.m. Central time.

Once the MPLM is in place, Mission Specialist Wendy Lawrence and Station Commander Sergei Krikalev will begin activation of the module about 8:49 a.m. EDT and will enter about two hours later, at 10:49 a.m. EDT.

Commander Eileen Collins and Mission Specialist Andy Thomas will participate in interviews with the Associated Press Radio Network, National Public Radio and the CBS Radio Network at 6:19 a.m. EDT.

Additional preparations for Saturday's first spacewalk of the mission by Soichi Noguchi and Steve Robinson will continue during the day with a review of EVA procedures and a checkout of a small rescue device known as SAFER, for Simplified Aid For EVA Rescue, designed to allow an astronaut outside a spacecraft to return safety if they become untethered and separated from the spacecraft. Hatches between Discovery and Station will be closed as the Shuttle's cabin pressure is reduced to 10.2 psi for the pre-breathe period, during which spacewalkers will become gradually acclimated to the lower pressures of spacesuits.

The crews of Discovery and the Station are scheduled to go to sleep about 3:39 p.m. EDT.

THURSDAY, JULY 28, 2005
1910 GMT (3:10 p.m. EDT)

The shuttle Discovery's crew might have dodged a bullet when a piece of foam debris broke away from an aerodynamic ramp on the side of the ship's external fuel tank during launch Tuesday. Had the foam broken away earlier, when the shuttle was deeper in Earth's atmosphere, the chunk could have hit the orbiter with potentially catastrophic results, engineers said today. Read our full story.

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

Discovery does pirouette, then docks to space station
Commander Eileen Collins guided the space shuttle Discovery to a picture-perfect docking with the international space station today, a major milestone in a mission now overshadowed by a crisis of confidence in NASA after the grounding of the shuttle fleet Wednesday. Read our full story.

1254 GMT (8:54 a.m. EDT)

HATCHWAY OPENED! Expedition 11 crewmembers Sergei Krikalev and John Phillips are welcoming the seven Discovery astronauts aboard the International Space Station, their first visitors in more than three months of living aboard the outpost.

All 9 crew members are now together and beginning their busy 8-day timeline of joint work. After an initial welcoming ceremony, station commander Krikalev will give a safety briefing.

1248 GMT (8:48 a.m. EDT)

The "go" has been given for hatch opening between Discovery and station.

1225 GMT (8:25 a.m. EDT)

The leak checks are progessing as planned with no problems reported.

1130 GMT (7:30 a.m. EDT)

The ring is retracted. Hooks and latches are now driving to firmly connect shuttle and station.

1128 GMT (7:28 a.m. EDT)

The docking ring between the two craft is being retracted into Discovery's Orbiter Docking System, pulling the station to a tight mating.

1118 GMT (7:18 a.m. EDT)

Docking occurred over the South Pacific west of Chile. NASA called the docking time as 7:18 a.m. EDT, rounding up the seconds to the nearest minute.

1117 GMT (7:17 a.m. EDT)

CONTACT AND CAPTURE! Discovery has docked to the International Space Station, the first space shuttle to reach the outpost in almost 1,000 days.

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's 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.

1116 GMT (7:16 a.m. EDT)

Ten feet to go. Discovery's thrusters are programmed to fire in a post-contact maneuver to force the two docking ports together. That procedure is now armed and ready.

1115 GMT (7:15 a.m. EDT)

Houston is calling Collins' approach "perfect."

1114 GMT (7:14 a.m. EDT)

Now 18 feet. Commander Eileen Collins is piloting Discovery from the aft flight deck control stick.

1113 GMT (7:13 a.m. EDT)

Discovery is 25 feet from docking.

1112 GMT (7:12 a.m. EDT)

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

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

Forty feet to go.

1107 GMT (7:07 a.m. EDT)

Now 65 feet separating Discovery from the station.

1102 GMT (7:02 a.m. EDT)

Less than 100 feet to go.

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

Discovery now 118 feet from the station. Mission Control says commander Eileen Collins has the shuttle is good alignment with the station docking port.

1058 GMT (6:58 a.m. EDT)

Now inside 150 feet from docking. Discovery is closing at 0.17 feet per second.

1052 GMT (6:52 a.m. EDT)

The shuttle is approaching to the station's front docking port along the velocity vector, or V-bar. Distance is now 200 feet.

1050 GMT (6:50 a.m. EDT)

The spacecraft have passed into orbital darkness. Sunrise will occur at 7:22 a.m. EDT.

1046 GMT (6:46 a.m. EDT)

The astronauts have powered up the Orbiter Docking System in Discovery's payload bay for the contact and capture with the station docking port.

1046 GMT (6:46 a.m. EDT)

Shuttle flight director Paul Hill has given the "go" for docking.

1045 GMT (6:45 a.m. EDT)

Now inside 300 feet from docking. Discovery is closing at 0.16 feet per second.

1039 GMT (6:39 a.m. EDT)

The shuttle is currently 337 feet out from the docking port.

1038 GMT (6:38 a.m. EDT)

Discovery has reached the point directly in front of the station.

1035 GMT (6:35 a.m. EDT)

The shuttle continues its trek from below the station to a point directly in front of the orbiting complex.

1030 GMT (6:30 a.m. EDT)

Discovery is making an arc from the point below to a point 400 in front of the space station to align with the docking port on the Destiny module.

1025 GMT (6:25 a.m. EDT)

All appears to have gone well with the Rendezvous Pitch Maneuver.

1020 GMT (6:20 a.m. EDT)

The opportunity to take pictures has ended for the station crew.

1019 GMT (6:19 a.m. EDT)

The shuttle is 180 degrees into this complete 360-degree flip.

1018 GMT (6:18 a.m. EDT)

Discovery pilot Jim Kelly has given the station crew a "go" to begin the 93-second period of photography.

1017 GMT (6:17 a.m. EDT)

Discovery continues its space pirouette over 200 miles above Europe.

1016 GMT (6:16 a.m. EDT)

This 9-minute, 360-degree backflip by Discovery will put the belly of the shuttle facing the station for the ISS crew to snap detailed pictures of the black tiles.

1015 GMT (6:15 a.m. EDT)

The Rendezvous Pitch Maneuver has begun.

1014 GMT (6:14 a.m. EDT)

The two craft are flying 223 miles above the north coast of Africa.

1011 GMT (6:11 a.m. EDT)

Discovery is now 650 feet below the station.

1009 GMT (6:09 a.m. EDT)

Distance is now 720 feet, closing at 0.6 feet per second.

1006 GMT (6:06 a.m. EDT)

Now 870 feet separating the two vehicles.

1005 GMT (6:05 a.m. EDT)

Commander Eileen Collins has taken manual control of Discovery for the rest of today's approach to docking.

1003 GMT (6:03 a.m. EDT)

Now inside 1,100 feet.

0958 GMT (5:58 a.m. EDT)

Just 1,600 feet separate Discovery and station.

0956 GMT (5:56 a.m. EDT)

Separation distance is now 2,000 feet.

On final approach, at a distance of about 600 feet directly below the station, commander Eileen Collins will carry out a slow 360-degree rendezvous pitch maneuver, or RPM, that will point the belly of the shuttle at the station.

As the shuttle's underside rotates into view, the station's two residents, Expedition 11 commander Sergei Krikalev and flight engineer John Phillips, shooting through windows at opposite ends of the station, will photograph Discovery's belly with handheld digital cameras equipped with 400- and 800-millimeter lenses. During an earlier expedition, science officer Donald Pettit took test photographs of approaching Russian spacecraft to determine what the station's cameras could actually see.

"The 800 millimeter gives them one-inch resolution, which is what we're looking for around (landing gear) door seals," shuttle flight director Paul Hill said. "400 millimeters gives three inches, which is what they're looking for everywhere else."

After completing the RPM maneuver, Collins will position Discovery directly ahead of the space station with the shuttle's nose facing deep space and its cargo bay facing the lab complex. She then will guide the spacecraft to a docking with a pressurized mating adaptor attached to the Destiny lab module, the first shuttle linkup with the outpost since Nov. 25, 2002.

After leak checks, Krikalev and Phillips will welcome the shuttle crew aboard and provide a brief safety briefing before all nine astronauts get down to work.

0950 GMT (5:50 a.m. EDT)

The station and shuttle crews have established radio contact between the two craft. Distance is now down to 5,500 feet.

0948 GMT (5:48 a.m. EDT)

The shuttle is now 6,500 feet from the station, closing at 8 feet per second. That closure rate will gradually slow and then be stopped once Discovery gets to a point inside 1,000 feet directly below the station for the pitch maneuver to present the belly to the station crew for photography.

0937 GMT (5:37 a.m. EDT)

Discovery remains on course for docking to the station. Distance between the two craft is now two-and-a-half miles.

0843 GMT (4:43 a.m. EDT)

With about eight statute miles separating Discovery and the space station, the shuttle has fired the Terminal Initiation maneuvering burn.

The TI burn puts the shuttle on a trajectory to directly intercept the orbiting station over the next orbit and a half. This burn represents the start of Discovery's final approach to the station after nearly two days of chasing the complex since launch. Docking is set for 7:18 a.m. EDT.

A detailed timeline of the docking activities is available here.

0500 GMT (1:00 a.m. EDT)

Discovery's crew was awakened for docking day at 11:39 p.m. EDT by "It's a Wonderful World" by Louis Armstrong for Camarda. The station crew was awakened at the same time by a tone onboard.

Here is the latest Mission Control status report:

Visitors on a Space Shuttle will arrive at the International Space Station for the first time in over two years today. The Space Shuttle Discovery is scheduled to catch up and dock to the Station at 7:18 a.m. EDT.

During Discovery's approach to the Station, Commander Eileen Collins will pause with the orbiter 600 feet below the Station and perform the first Rendezvous Pitch Maneuver. The motion will flip the Shuttle end over end at three quarters of a degree per second as the Station residents look on with digital cameras at the ready. The flip will provide Expedition 11 crewmembers, Sergei Krikalev and John Phillips, about 93 seconds to photograph the underside of Discovery and its heat-resistant tiles in detail.

The images from Station will be downlinked and added to the host of imagery and data obtained during Discovery's launch and Wednesday's robotic surveys that engineers are analyzing. Imagery released Wednesday showed a piece of foam being shed from the external tank during Discovery's ascent. Other photos showed a variety of smaller tile and foam dings that will be reviewed over the next several days. The crew will also downlink the video taken of the External Tank as it fell away from Discovery on Tuesday and video of the clearance between the Orbiter Boom Sensor System and the Ku-band antenna for review.

Once Discovery's crew has had a safety briefing from the Space Station crew, both crews get to work with more robotic operations to prepare for additional surveys. Discovery Pilot Jim Kelly, Mission Specialist Wendy Lawrence, with assistance from Phillips, will operate the Space Station robotic arm, Canadarm2, from inside the Destiny Lab. They will use the arm to lift the Orbiter Boom Sensor System from the payload bay sill and hand it over to the Shuttle arm. Mission Specialists Charlie Camarda and Andy Thomas will operate the Shuttle arm. Clearance restraints around the Shuttle's docking mechanism do not allow the Shuttle arm to grapple the boom on its own.

Spacewalkers Steve Robinson and Soichi Noguchi have two hours to prepare their tools and equipment for their three spacewalks. Among other things, the first spacewalk Saturday will test thermal protection system repair techniques. Two other spacewalks will repair and install critical hardware outside the Station.

WEDNESDAY, JULY 27, 2005

In a major setback for NASA, senior managers today grounded the shuttle fleet, saying no more missions will be launched until engineers figure out why large, potentially catastrophic pieces of foam insulation broke away from the shuttle Discovery's external fuel tank during launch Tuesday. Read our full story.

2257 GMT (6:57 p.m. EDT)

Had this PAL ramp foam broken free earlier in the ascent, "it would have been bad," Hale says. Luckily for Discovery, the foam came off over two minutes into flight following solid rocket booster separation when the vehicle was nearly out of the atmosphere.

Columbia was hit about 81 seconds after liftoff by the bipod ramp.

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

"It didn't harm the orbiter and we learned something," Parsons says of looking on the bright side.

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

Is the shuttle program done launching for 2005? Parsons: "I can't say what the impact of this is." Shuttles can't fly with this large size foam coming off, he added. The problem must be dealt with before the next launch can occur.

Plans had called for Atlantis to launch September 9.

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

The images and information on the foam loss have been uplinked to the astronauts, Hale confirms.

2233 GMT (6:33 p.m. EDT)

Hale says Discovery appears to be good shape, but the final rationale for returning to Earth as-is or whether any repairs are necessary will be made later this week.

2232 GMT (6:32 p.m. EDT)

Images from the umbilical well on Discovery looking at the jettisoned tank as it moved away shows foam divots in the foam near the struts that connect the orbiter's nose to the tank. These are "areas not satisfactory to us" for foam loss, Hale says.

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

Hale says NASA wanted to remove the PAL ramp foam. But aerodynamically it was determined they were needed to cover the cable trays and pressurization lines running along the tank's exterior. Whether the foam could be replaced with a metal cover is one possibility.

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

Mission Management Team chairman Wayne Hale says engineers are treating chipped tile on the nose landing gear door seriously but "not losing sleep" over it. Further observations will be needed to determine the exact size and depth of the divot.

There's also a tile hit a bit lower on the underside. The station crew will be imaging Discovery's belly during approach before docking in the morning.

2214 GMT (6:14 p.m. EDT)

The redesigns to the external fuel tank weren't enough, Parsons said, given the loss of foam yesterday. "Obviously, we have more work to do."

The Discovery launch saw foam shed from a different area than the biopod foam that hit Columbia.

2212 GMT (6:12 p.m. EDT)

Parsons says the next shuttle launch will not occur until this foam loss is understood and resolved. "I don't know when that will be."

2211 GMT (6:11 p.m. EDT)

The lost PAL ramp foam did not hit the orbiter, Parsons says.

2208 GMT (6:08 p.m. EDT)

The post-Mission Management Team meeting news conference is now underway. Shuttle program manager Bill Parsons said there was "an unexpected debris event" with Discovery's external tank losing foam.

2143 GMT (5:43 p.m. EDT)

Debris seen falling away from the shuttle Discovery's external fuel tank during launch Tuesday was a large piece of foam insulation from a so-called "ramp" used to prevent turbulent airflow around cable trays and pressurization lines, NASA officials said today. Other areas of foam loss could be seen in images of the tank shot by Discovery's crew and released by NASA Wednesday. Read our full story.

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

Additional images of the tank showing the missing foam are available here and here and here.

NASA is planning a 6 p.m. EDT news conference to discuss the situation.

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

An image of the missing area of foam from the PAL ramp is available here.

2055 GMT (4:55 p.m. EDT)

Images and video taken from shuttle Discovery of the discarded external fuel tank following launch yesterday has revealed a section of foam from the Protuberance Air Load (PAL) ramp came off the tank. The debris appeared to just miss striking the orbiter's right wing. We'll post the pictures here momentarily.

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

Mission control has wished the crew of Discovery good night after a busy first day in orbit. "We're ready for the rendezvous tomorrow," said shuttle commander Eileen Collins. The astronauts will sleep until 11:39 p.m. EDT (0339 GMT Thursday) tonight. Discovery is scheduled to dock with the International Space Station at 7:18 a.m. EDT (1118 GMT) tomorrow.

1851 GMT (2:51 p.m. EDT)

Flight controllers have e-mailed the crew a PowerPoint presentation containing details of the early analysis of imagery captured during Discovery's climb to orbit yesterday. Mission managers are expected to reveal the initial findings to the news media in a press conference scheduled for 5 p.m. EDT today.

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

NASA believes the bird struck by Discovery's fuel tank was a buzzard. These large birds can have a wing span of more than six feet and the average weight of a full-grown bird is 6.5 lbs.

"It was in the wrong place at the wrong time," a Kennedy Space Center spokesperson said.

NASA has long assumed that the noisy launch pad environment at the time of main engine ignition would cause bird to fly away from the launching shuttle.

Workers had not located the carcass of the bird but not all areas of the launch complex had been searched.

Images of the strike are available here.

Subscribers of our Spaceflight Now Plus service can see a video clip of the bird strike here.

The incident is one of several NASA is studying from yesterday's launch, along with the chipped nose gear door tile and external tank debris-shedding event.

1550 GMT (11:50 a.m. EDT)

"There are some folks in the imagery world that have found some things that they are concerned about on the tank. I have not persobnally been involved in any of the analysis and I cannot help you to understand what the imagery folks have seen on the tank at all," lead shuttle flight director Paul Hill told reporters a short time ago during today's mission status briefing.

Although he didn't have much additional information, he did say: "They are concerned about some things they have seen on the PAL ramp."

Known as the Protuberance Air Load (PAL) ramp, this area of foam was designed to prevent unsteady air flow underneath the tank's cable trays and pressurization lines. This could be the source of the debris seen breaking off the tank after solid rocket booster separation.

The Mission Management Team will be meeting this afternoon to review the ongoing engineering analysis of launch photography. NASA will hold a news conference at 6 p.m. EDT following the meeting to brief the news media and public on the situation.

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

The boom inspections have been completed for today. The crew will be putting the boom back into its cradle on the starboard side of Discovery's payload bay.

1352 GMT (9:52 a.m. EDT)

The docking ring atop the Orbiter Docking System in Discovery's payload bay has been successfully extented into position for tomorrow's linkup with the space station. This ring is what makes first contact and capture with the station docking port.

1326 GMT (9:26 a.m. EDT)

As part of routine preparations for the mission's three spacewalks, Soichi Noguchi and Stephen Robinson spent time this morning checking out their equipment and spacesuits to be used on the excursions. No significant problems have been reported so far.

1316 GMT (9:16 a.m. EDT)

The crew reports the nose cap inspections are complete, much sooner than controllers had predicted. The astronauts are going to take a break before pressing ahead with the port wing survey.

1240 GMT (8:40 a.m. EDT)

The astronauts completed the laser scanning of the starboard wing and then swung the boom out in front of Discovery to begin studying the ship's gray reinforced carbon carbon nose cap. Mission Control expects it will take another 90 minutes to finish these observations. Next up will be moving the boom over to the port wing for inspections of its leading edge panels.

1000 GMT (6:00 a.m. EDT)

The methodical scanning of Discovery's wing leading edge panels using the shuttle's new 50-foot sensor boom is underway.

"We're ready on page 2-dash-7 to get the show on the road. If you concur, we will start," mission specialist Andy Thomas radioed Houston about 5:42 a.m. EDT.

Mission Control gave the final approval, allowing the inspections to begin on the 22 RCC panels that make up the shuttle's starboard wing. The nose cap and the port wing will be scanned as the day continues.

Today's checks of the shuttle are unrelated to the debris events seen during Discovery's launch. The crew always planned to inspect the vehicle on the second day of the mission as a direct result from a recommendation made by the Columbia Accident Investigation Board.

0730 GMT (3:30 a.m. EDT)

The Discovery astronauts geared up for a detailed inspection of the shuttle's reinforced carbon carbon nose cap and wing leading edge panels today. The post-Columbia safety survey is designed to spot any entry-critical damage to the areas of the shuttle that experience the most extreme heating during the return to Earth. Read our full story.

0540 GMT (1:40 a.m. EDT)

A detailed look at the astronauts' timeline for today is available here.

And the latest revision of the NASA Television schedule has been posted.

0515 GMT (1:15 a.m. EDT)

The seven astronauts have started Flight Day Two aboard Discovery. Here is the latest status report from Mission Control:

The crew aboard the Space Shuttle Discovery has awakened to its first full day in space. Today it will focus on thermal protection system inspections, preparing for docking to the International Space Station and getting spacesuits ready for three spacewalks.

Commander Eileen Collins, Pilot Jim Kelly and Mission Specialists Soichi Noguchi, Steve Robinson, Andy Thomas, Wendy Lawrence and Charlie Camarda received a wakeup call at 12:39 a.m. EDT. The song played for the crew was music from the movie "Groundhog Day," which was for the entire crew to commemorate its first day out of quarantine.

For most of the day, Thomas, Camarda and Kelly will work together on Discovery's aft flight deck to inspect key components of the orbiter's heat shield. For the majority of the inspections the new Orbiter Boom Sensor System (OBSS) laser-scanner will be used. The Shuttle's robotic Canadarm will be used to maneuver the 50-foot boom extension after checkout of the system is completed.

In its debut performance, the boom will be used to methodically inspect the leading edges of Discovery's wings and the orbiter's nose cap to insure that they did not incur any damage during launch. The Laser Dynamic Range Imager (LDRI) on the boom will provide two-and three-dimensional imagery. The data will be downlinked to the ground for engineering evaluation.

After those surveys are complete the boom will be placed back on the starboard sill of the payload bay. The Shuttle robotic arm and its cameras will then be used to survey Discovery's crew cabin. Additionally, using handheld digital cameras the crew will photograph tiles on the Orbital Maneuvering System (OMS) pods and the orbiter's tail.

During Tuesday's ascent to orbit, the enhanced imaging capability gave flight controllers and mission managers views of the Shuttle Orbiter never seen before. With this heightened ability, engineers were able to see two so-called "debris events." A camera mounted on the external tank caught what appeared to be a small fragment of tile coming from Discovery's underside on or near the nose gear doors. A later image about the time of Solid Rocket Booster separation showed an unidentified piece departing from the tank and exiting away, apparently not striking the orbiter. The crew was notified of these observations and told that imaging experts would be analyzing the pictures.

Mission managers will review the information gathered yesterday and today, including imaging and sensor data, to help determine the health of Discovery's thermal protection system over the next four days before it is cleared for landing later in the flight. Data from the new wing leading edge sensors was downlinked overnight to Mission Control for assessment.

Flight Day Four has time reserved for additional surveys, if required, using the OBSS, either to complete parts of the survey that time would not allow today, or to supplement the survey with "stop-and-stare" scans of sites of potential interest.

Meanwhile, on the middeck, spacewalkers Noguchi and Robinson, assisted by Lawrence, will check out the airlock, spacesuits and tools they will begin using on Saturday. They will also prepare Shuttle systems for docking to the Space Station.

Today Collins will fire Discovery's thrusters twice to refine its approach to the Station. At about 1 a.m. EDT, Discovery was trailing the Station by 6,516 statute miles. The two are scheduled to link up at 7:18 a.m. EDT Thursday.

Today the Space Station crew, Commander Sergei Krikalev and Flight Engineer and NASA Science Officer John Phillips will prepare the complex for Discovery's arrival. They will configure the digital cameras they will use during Discovery's approach, gathering additional imagery of the Shuttle's heat shield. They also will pressurize the Pressurized Mating Adapter 2 (PMA 2) that Discovery will dock to Thursday.

TUESDAY, JULY 26, 2005

The shuttle Discovery, carrying seven astronauts, critical space station supplies and the hopes of a nation, rocketed into orbit today in a nerve-wracking bid to revive America's human space program two-and-a-half years after the Columbia disaster. But at least two pieces of debris seen falling from the shuttle shortly after launch brought back haunting memories of Columbia, prompting intensive analysis to determine what, if any, threat they might pose. Read our full story.

Click here to see pictures from the bird strike, chipped tile and tank debris events.

2150 GMT (5:50 p.m. EDT)

In the news conference underway, the ground radar observations detected the chipped tile falling away. Using the onboard external tank video, engineers were able to spot where the tile piece had come from.

Check back a little later for a complete story.

2132 GMT (5:32 p.m. EDT)

The piece of chipped tile that can be seen in the onboard video camera probably came from a tile 8.5 inches wide. The broken piece that fell away is estimated to be about 1.5-in. How deep the tile divot on Discovery isn't known.

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

Launch imagery also reveals the top of the external tank hit a bird about 2.5 seconds after liftoff.

2125 GMT (5:25 p.m. EDT)

In the mission status briefing that just started in Houston, officials confirm a black tile can be seen chipping on Discovery's underside nose gear door area near where the bipod attaches the tank to the orbiter. What caused that isn't clear. Later in flight the tank shed a piece of debris after solid rocket booster separation, but the debris did not hit Discovery.

Teams are processing through radar data taken during launch and going frame by frame of onboard and ground imagery.

Officials stress they are just beginning to examine all of the available data from the launch and it's much too early to draw any conclusions.

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

The crew reports launch data was recorded by the 88 sensors installed behind the wing leading edges of Discovery to detect impact strikes and temperature changes. That data is being downlinked to engineers on the ground for planned post-launch analysis to determine if the shuttle suffered any hits during ascent. Also, the astronauts say the new digital still camera in Discovery's belly umbilical well snapped pictures of the discard external tank to determine the tank's condition.

The data becomes even more critical since onboard video and ground radar have detected debris-shedding events during launch. Whether Discovery was impacted is not clear at this time.

Meanwhile, NASA has released unprecedented aerial views from a pair of WB-57 high-altitude aircraft that tracked Discovery during launch. We'll be posting that video shortly.

And a mission status news conference from Johnson Space Center in Houston is expected to begin any minute now.

2039 GMT (4:39 p.m. EDT)

Mission Control just radioed commander Eileen Collins with news that both the onboard external tank video camera and ground radar did detect two debris "events" around the time of solid rocket booster separation. The tank camera showed something breaking free from the fuel tank and falling away a few moments after the boosters separated. The imagery analysis team is reviewing all of the data and plan to meet late tonight. More information will be provided to the crew when they awake for the start of Flight Day 2 at 12:39 a.m. EDT tonight.

As part of this test flight for the shuttle program, the crew will use a camera- and sensor-laden 50-foot long boom tomorrow to inspect the leading edges of the wings and orbiter nose cap. That inspections will go forward as planned, Mission Control told the crew.

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

The astronauts just completed the NC-1 rendezvous burn using the twin Orbital Maneuvering System engines on the tail of Discovery. This particular maneuver was designed to raise the shuttle's orbital altitude and slow the approach to the station by 310 feet per second.

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

The astronauts are settling into life in space aboard Discovery. The payload bay doors were opened a little more than an hour ago and the crew is progressing through their post-launch activities.

The ascent flight control team in Houston has completed its job today, turning duties over to the Orbit 2 team of controllers for the rest of the astronauts' day. Many of the ascent team members will handle entry and landing for Discovery's return to Earth on August 7.

"We know the folks back on the planet Earth are just feeling great right now and our thanks to everybody for all of the super work that's been down over the past two-and-a-half years to get us flying again," commander Eileen Collins radioed CAPCOM astronaut Ken Ham in Mission Control.

"And I do want to pass on from those of us who have flown before, that was by far the smoothest ascent through first stage and up to MECO (main engine cutoff) that we've ever experienced. And the great weather and everything put together, nice ascent with no malfunctions, (you) couldn't ask for a better flight. So thanks to everybody down there on the ascent team and we're looking forward to seeing ya in 12 or 13 days for entry and landing."

"You got it Eileen," Ham replied. "We'll bring you home safe then."

Crew sleep time will be coming up at 4:39 p.m. EDT. A mission status briefing follows at 5 p.m. EDT.

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

The shuttle Discovery, carrying seven astronauts, critical space station supplies and the hopes of a nation, rocketed smoothly into orbit today in a nerve-wracking bid to revive America's space program two-and-a-half years after the Columbia disaster. Read our full story.

1605 GMT (12:05 p.m. EDT)

Mission management team chairmain Wayne Hale says he doesn't know any details about the debris coming off the tank noted just after booster separation. He said the film experts will be studying all launch footage frame by frame, as was planned going into this first post-Columbia launch.

1559 GMT (11:59 a.m. EDT)

The post-launch press conference is beginning here at Kennedy Space Center.

1522 GMT (11:22 a.m. EDT)

An image from the external tank video shows the chunk of debris breaking away from the tank just after the solid boosters separated. See the image here.

1518 GMT (11:18 a.m. EDT)

T+plus 39 minutes, 30 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. The new orbit is 142 by 98 statute miles. The next maneuvering burn is coming up around 4 p.m. EDT to raise the orbit to 191 by 141 miles as the rendezvous continues to reach the station.

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

T+plus 38 minutes, 20 seconds. The maneuvering engines have ignited for the orbit raising burn.

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

T+plus 33 minutes. A few seconds after solid rocket booster separation, a large chunk of something broke free from the external fuel tank. The onboard video camera mounted on the tank showed the object flying away from the vehicle without striking Discovery.

1511 GMT (11:11 a.m. EDT)

T+plus 32 minutes. Discovery will be reorienting itself into the upcoming OMS engine firing, which will boost the shuttle into an orbit of 140 by 98 statute miles.

1509 GMT (11:09 a.m. EDT)

T+plus 30 minutes. The two flapper doors on the belly of Discovery are being swung closed to shield the umbilicals that had connected to the external fuel tank.

1454 GMT (10:54 a.m. EDT)

T+plus 15 minutes. This morning's launch appeared to go smoothly with no system problems reported in Mission Control.

1453 GMT (10:53 a.m. EDT)

T+plus 14 minutes. Discovery has reached a preliminary sub-orbital trajectory of 137 by 36 statute miles. In about 23 minutes, the Orbital Maneuvering System engines will be fired to raise the low point to a safe altitude.

1450 GMT (10:50 a.m. EDT)

T+plus 11 minutes, 45 seconds. Andy Thomas is taking still images while Soichi Noguchi shoots camcorder video.

1448 GMT (10:48 a.m. EDT)

T+plus 9 minutes, 50 seconds. Commander Collins will be pitching Discovery so the crew can use cameras to image the just-discard external fuel tank.

1448 GMT (10:48 a.m. EDT)

T+plus 9 minutes, 25 seconds. A normal engine cutoff occurred and an additional boost from the Orbital Maneuvering System engines is not required.

1447 GMT (10:47 a.m. EDT)

T+plus 8 minutes, 48 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.

1447 GMT (10:47 a.m. EDT)

T+plus 8 minutes, 34 seconds. MECO! Confirmation that Discovery's main engines have cutoff as planned, completing the powered phase of the launch.

1446 GMT (10:46 a.m. EDT)

T+plus 7 minutes, 35 seconds. The main engines beginning to throttle back to ease the force of gravity on the shuttle and astronauts.

1446 GMT (10:46 a.m. EDT)

T+plus 7 minutes. Main engines continue to perform well as Discovery nears the completion of powered ascent.

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

T+plus 6 minutes, 30 seconds. The shuttle can now reach orbit on two engines.

1444 GMT (10:44 a.m. EDT)

T+plus 5 minutes, 55 seconds. Discovery is rolling to a heads-up position.

1444 GMT (10:44 a.m. EDT)

T+plus 5 minutes, 25 seconds. Discovery can now reach a orbit on the power of two main engines should one fail. But all three continue to fire properly.

1443 GMT (10:43 a.m. EDT)

T+plus 4 minutes, 50 seconds. Discovery is 200 miles northeast of the launch pad at an altitude of 65 miles, traveling over 6,000 mph.

1443 GMT (10:43 a.m. EDT)

T+plus 4 minutes, 10 seconds. Negative return. The shuttle is traveling too fast and is too far downrange so it can no longer return to the launch site in the event of a main engine problem.

1442 GMT (10:42 a.m. EDT)

T+plus 3 minutes, 15 seconds. Discovery is 85 miles northeast of the launch pad at an altitude of 48 miles and traveling 4,500 mph.

1442 GMT (10:42 a.m. EDT)

T+plus 3 minutes. Discovery's main engines continue to fire, guzzling a half-ton of propellant per second.

1441 GMT (10:41 a.m. EDT)

T+plus 2 minutes, 10 seconds. The twin solid rocket boosters have done their job and separated from the space shuttle Discovery. The shuttle continues its climb to orbit on the power of the three liquid-fueled main engines.

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

T+plus 90 seconds. All systems of Discovery are performing well as the shuttle accelerates to orbit. Burning propellant at remarkable rates, the shuttle weighs half of what it did at liftoff.

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

T+plus 75 seconds. Discovery's engines have revved back to full throttle. Mission Control has given the "go" at throttle call and commander Eileen Collins has acknowledged that. No problems have been reported in this morning's ascent.

1439 GMT (10:39 a.m. EDT)

T+plus 35 seconds. Discovery's three main engines are being throttled down to lessen the aerodynamic stresses on the vehicle as it powers through the dense lower atmosphere.

1439 GMT (10:39 a.m. EDT)

T+plus 20 seconds. The shuttle has rolled to the proper heading for its northeasterly trajectory up the Eastern Seaboard on the two-day chase to catch the orbiting International Space Station. The outpost is currently flying half-a-world away above the southern Indian Ocean.

1439 GMT (10:39 a.m. EDT)

LIFTOFF! America's space shuttle program returns to flight as Discovery clears the tower!

1438 GMT (10:38 a.m. EDT)

T-minus 31 seconds. Auto sequence start. Discovery's onboard computers have taken control of the final half-minute of the countdown.

In the next few seconds the solid rocket booster hydraulic power units will be started, a steering check of the booster nozzles will be performed and the orbiter's body flap and speed brake will be moved to their launch positions. The main engine ignition will begin at T-minus 6.6 seconds.

1438 GMT (10:38 a.m. EDT)

T-minus 1 minute. Computers verifying that the main engines are ready for ignition. Sound suppression water system is armed. System will activate at T-minus 16 seconds to suppress the sound produced at launch. Residual hydrogen burn ignitors have been armed. They will be fired at T-minus 10 seconds to burn off any hydrogen gas from beneath the main engine nozzles. And the solid rocket booster joint heaters have been deactivated.

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.

1437 GMT (10:37 a.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 of the flight load of liquid hydrogen in the external tank will be terminated and tank pressurization will begin.

1436 GMT (10:36 a.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 Jim Kelly has been asked to clear the caution and warning memory system aboard Discovery.

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

1436 GMT (10:36 a.m. EDT)

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

1435 GMT (10:35 a.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.

1435 GMT (10:35 a.m. EDT)

T-minus 4 minutes. Activation of the APUs complete. The three units are up and running. The final helium purge sequence is under way 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.

1434 GMT (10:34 a.m. EDT)

T-minus 5 minutes. The "go" has been given for for Auxiliary Power Unit start. Pilot Jim Kelly 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 are 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 Eileen Collins, 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.

1433 GMT (10:33 a.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 now in the record mode to collect measurements of shuttle systems performance during flight.

1433 GMT (10:33 a.m. EDT)

T-minus 6 minutes. Pilot Jim Kelly has been asked by Orbiter Test Conductor Mark Taffet 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.

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

T-minus 7 minutes, 30 seconds. The ground launch sequencer is now 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 in about a quarter of a minute should the need arise later in the countdown.

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

T-minus 8 minutes and counting. Pilot Jim Kelly 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 for the final antenna alignment and management for today's launch.

1430 GMT (10:30 a.m. EDT)

T-minus 9 minutes and counting. The ground launch sequencer is now controlling the final phase of today's countdown to launch of space shuttle Discovery at 10:39 a.m. EDT. The GLS will monitor as many as a thousand different measurements to ensure they do not fall out of predetermine red-line limits.

1428 GMT (10:28 a.m. EDT)

The countdown will resume in two minutes.

Once the countdown picks up, the Ground Launch Sequencer will be 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.

1426 GMT (10:26 a.m. EDT)

NASA Launch Director Mike Leinbach has finished his final poll. He has wished commander Collins and crew "good luck and God speed!" Launch is set for 10:39 a.m.

1425 GMT (10:25 a.m. EDT)

The final readiness poll by NASA Test Director Jeff Spaulding has been completed with all launch team members reporting "go", including the orbiter, external tank, solid rocket boosters, safety personnel, Eastern Range and the astronaut crew.

1422 GMT (10:22 a.m. EDT)

Standing by for the status polls to give approval to continue with the countdown.

1419 GMT (10:19 a.m. EDT)

The Eastern Range has confirmed its clearance for launch this morning.

1418 GMT (10:18 a.m. EDT)

The Orbiter Closeout Crew has arrived back at the fallback area a safe distance from the launch pad.

1417 GMT (10:17 a.m. EDT)

The final test of the engine cutoff sensors has been completed. All of the sensors continue to operate normally in today's countdown.

1409 GMT (10:09 a.m. EDT)

Now 30 minutes away from launch time.

Two solid rocket booster recovery ships -- the Freedom Star and Liberty Star -- are on station in the Atlantic Ocean about 140 miles northeast of Kennedy Space Center, off the coast of Jacksonville, Florida. They were deployed from Port Canaveral on Sunday to support the launch.

The ships will retrieve and return the spent boosters to the Cape for disassembly and shipment back to Utah for refurbishment and reuse on a future shuttle launch.

Following the boosters' parachuted descent and splashdown in the Atlantic, the recovery teams will configure the SRBs for tow back to Port Canaveral this week.

1351 GMT (9:51 a.m. EDT)

All of the optical tracking sites are reporting to be ready for observing Discovery's launch. A pair of WB-57 high-altitude aircraft are flying off the coast in a holding pattern to intercept the shuttle to provide a never-before-seen view of Discovery during ascent.

1345 GMT (9:45 a.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 10:39:00 a.m. EDT. There are no significant technical problems being reported and the weather is just fine.

1342 GMT (9:42 a.m. EDT)

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

1339 GMT (9:39 a.m. EDT)

T-minus 15 minutes. Now one hour away from launch time. Pilot Jim Kelly is configuring the displays inside Discovery's cockpit for launch while commander Eileen Collins enables the abort steering instrumentation. And Mission Control in Houston is loading Discovery's onboard computers with the proper guidance parameters based on the projected launch time.

1334 GMT (9:34 a.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 adjust to synch up with today's preferred launch time of 10:39 a.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.

1331 GMT (9:31 a.m. EDT)

The launch team has received a briefing on today's countdown from the NASA test director. Clocks will resume in three minutes.

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

T-minus 20 minutes and holding. The countdown has paused for a 10-minute built-in hold. Launch remains scheduled for 10:39 a.m. EDT.

During this built-in hold, all computer programs in Firing Room 3 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.

1316 GMT (9:16 a.m. EDT)

The shuttle's backup flight control system (BFS) computer has been configured. It would be used today in the event of emergency landing.

Also, the primary avionics software system (PASS) has transferred to Discovery's BFS computer so both systems can be synched with the same data. In case of a PASS computer system failure, the BFS computer will take over control of the shuttle vehicle during flight.

1314 GMT (9:14 a.m. EDT)

Commander Eileen Collins has pressurized the gaseous nitrogen system for Discovery's Orbital Maneuvering System engines, and pilot Jim Kelly has activated the gaseous nitrogen supply for the orbiter's Auxiliary Power Units' water boilers.

1310 GMT (9:10 a.m. EDT)

The weather forecast has improved once again. The prediction now calls for a 90 percent chance of acceptable conditions at the 10:39 a.m. EDT launch time. Weather at the abort landing sites across the Atlantic shouldn't be a stopper in the countdown either, meteorologists say.

1306 GMT (9:06 a.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.

1305 GMT (9:05 a.m. EDT)

The crew module hatch is closed and latched for flight.

1300 GMT (9:00 a.m. EDT)

Discovery's crew module hatch has swung shut and the Orbiter Closeout Crew is working to latch it. Pressure and leak checks will be performed shortly to ensure a good seal on the hatch for today's launch.

Meanwhile, the Ground Launch Sequencer mainline activation is starting. The GLS is the master computer program that controls the final 9 minutes of the countdown, monitoring as many as a 1,000 different systems and measurements to ensure they do not fall out of pre-determined limits.

1257 GMT (8:57 a.m. EDT)

The "go" has been given to close the shuttle's crew compartment hatch.

1251 GMT (8:51 a.m. EDT)

The official launch window today extends from 10:34:33 to 10:43:52 a.m. EDT. The preferred liftoff time that NASA is targeting is 10:39:00 a.m. for better launch performance.

1249 GMT (8:49 a.m. EDT)

The pre-flight alignment of Discovery's Inertial Measurement Units is underway and will be completed by the T-minus 20 minute mark. The IMUs were calibrated over the past few hours of the countdown. The three units are used by the onboard navigation systems to determine the position of the orbiter in flight.

Meanwhile, the S-band antennas at the MILA tracking station here at the Cape will soon shift from low power to high power. The site will provide voice, data and telemetry relay between Discovery and Mission Control during the first few minutes of flight. Coverage then is handed to a NASA Tracking and Data Relay Satellite in space.

1245 GMT (8:45 a.m. EDT)

The Orbiter Closeout Crew is removing all non-flight items from Discovery in advance of closing the hatch for flight.

1243 GMT (8:43 a.m. EDT)

The official target launch time has been revised to 10:39:00 a.m. EDT, based on the orbit of the international space station.

1242 GMT (8:42 a.m. EDT)

All of the weather rules are "go" for launch right now.

1232 GMT (8:32 a.m. EDT)

A series routine communications checks between the Discovery crew and various audio channels is underway.

1214 GMT (8:14 a.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 10:39 a.m.

With all seven astronauts inside Discovery's crew module, preparations will soon begin to close the hatch by the Orbiter Closeout Crew.

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.

1208 GMT (8:08 a.m. EDT)

The seventh and final member of Discovery's crew is now inside the shuttle. Mission specialist No. 2, Steve Robinson, is heading to the flight deck's center seat.

Robinson has flown on two earlier shuttle missions in the late 1990s. Read his biography here.

1204 GMT (8:04 a.m. EDT)

The countdown is still ticking along without any problems. The weather conditions are favorable and the engine cutoff sensors that caused the scrub two weeks ago are operating normally today.

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

Japanese astronaut and Discovery's mission specialist No. 1, Soichi Noguchi, is climbing to the flight deck aft-right seat.

Noguchi will be making his first flight into space on STS-114. Read his biography here.

1153 GMT (7:53 a.m. EDT)

Astronaut Wendy Lawrence, mission specialist No. 4, has crawled through the hatch. She will take the middeck's center seat.

Lawrence is a three-time shuttle flier. Read her biography here.

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

Now three hours from launch.

1137 GMT (7:37 a.m. EDT)

Mission specialist No. 3 Andy Thomas is aboard Discovery now. He is positioned closest to the hatch in the left seat on the middeck.

Thomas is the most experienced space traveler of Discovery's crew. He spent four months living aboard the Russian space station Mir in 1998, plus flew shuttle missions in 1996 and 2001. Read his biography here.

1131 GMT (7:31 a.m. EDT)

Pilot Jim Kelly is the next crewmember to enter the shuttle. He is making his way to the flight deck's front-right seat.

Kelly has one previous shuttle flight to his credit. Read his biography here.

1123 GMT (7:23 a.m. EDT)

Now climbing through the hatch is mission specialist No. 5, Charlie Camarda. He is assigned the right seat on the middeck.

Camarda is a spaceflight rookie, Read his biography here.

1118 GMT (7:18 a.m. EDT)

As shuttle commander, Collins is the first astronaut to board the shuttle. She is taking her forward-left seat on the flight deck.

Collins has flown in space on three earlier missions, becoming the first woman shuttle pilot and commander. Read her biography here.

1112 GMT (7:12 a.m. EDT)

Commander Eileen Collins has made her way across the catwalk-like Orbiter Access Arm to the White Room positioned against the side of Discovery. The closeout crew is helping her don other survival gear.

1111 GMT (7:11 a.m. EDT)

The Discovery astronauts have reached the 195-foot level of the tower.

1108 GMT (7:08 a.m. EDT)

The next round of tests on the engine cutoff sensors is beginning.

1107 GMT (7:07 a.m. EDT)

Discovery's crew arrived at launch pad 39B at 7:07 a.m. The AstroVan just came to a stop on the pad surface near the Fixed Service Structure tower elevator that will take the seven-person crew to the 195-foot level to begin boarding the shuttle this morning.

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

The AstroVan is passing the 52-story Vehicle Assembly Building where Discovery was mated to its external tank and solid rocket boosters. Some reporters across the street at the press site are braving the weather and going outside to wave at the convoy as it passes by, which is a launch day tradition to say farewell and good luck to the astronaut crews.

1049 GMT (6:49 a.m. EDT)

On their way! Commander Eileen Collins and her six fellow crewmates have emerged from the Kennedy Space Center crew quarters to board the AstroVan for the 7-mile ride from the Industrial Area to launch pad 39B on the edge of the Atlantic Ocean.

1044 GMT (6:44 a.m. EDT)

T-minus 3 hours and counting. The countdown has resumed on schedule from this planned three-hour built-in hold. Clocks will now tick down to T-minus 20 minutes when the next hold is planned. A final hold is scheduled at the T-minus 9 minute mark to synch up with the 10:39 a.m. EDT launch time.

1039 GMT (6:39 a.m. EDT)

The countdown is entering the final four hours to launch of Discovery this morning. The Final Inspection Team has completed its observations at pad 39B. The team is headed to the Launch Control Center where a briefing will be giving to management on what was seen on the vehicle and pad structures.

1030 GMT (6:30 a.m. EDT)

All seven astronauts have donned their day-glow orange launch and entry partial pressure spacesuits. After final adjustments and pressure checks, the crew plans to depart the suit-up 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 39B. We expect to see the crew walk out of the O&C Building around 6:49 a.m. EDT.

1016 GMT (6:16 a.m. EDT)

The pre-launch astronaut weather briefing has just been completed. The commander, pilot and flight engineer received an update on conditions predicted at runways here at Kennedy Space Center, on the U.S. West Coast and the trans-Atlantic abort landing sites in the event a problem forced Discovery to abort the mission and make an emergency return to Earth following liftoff.

For STS-114, a new overseas landing site has been activated in Istres-le-Tube, France. This locale replaces Ben Guerir, Morocco. The other two TAL sites continue to be Moron and Zaragoza, Spain.

The Abort Once Around, or AOA, sites are California's Edwards Air Force Base and White Sands, New Mexico.

Overall, the weather outlook is favorable today.

0954 GMT (5:54 a.m. EDT)

The countdown is still holding at the T-minus 3 hour mark. Clocks are slated to resume ticking in 50 minutes.

0923 GMT (5:23 a.m. EDT)

No significant problems or concerns have been reported by the inspection team so far.

0915 GMT (5:15 a.m. EDT)

The inspection team is responsible for checking Discovery and the 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.

0900 GMT (5:00 a.m. EDT)

Discovery's seven astronauts are seated around the dining room table in crew quarters for a pre-launch snack. They were awakened at 12:30 a.m. EDT to begin the launch day activities at Kennedy Space Center. Just like the first launch attempt two weeks ago, flight engineer Steve Robinson was playing a guitar at the table.

After a bite to eat, commander Eileen Collins, pilot Jim Kelly and Robinson will receive a briefing on the weather forecast for KSC and abort landing sites in California, New Mexico, Spain and France. Then they will join their crewmates in the suit-up to don the launch and entry spacesuits in preparation for heading to pad 39B.

0855 GMT (4:55 a.m. EDT)

The MILA tracking station here at Merritt Island has aligned its communications antennas with the launch pad and initial communications checks with the Air Force-controlled Eastern Range have been performed. Also, the pre-flight calibration of Discovery's three inertial measurement unit guidance computers began, NASA reports.

0845 GMT (4:45 a.m. EDT)

Discovery's seven astronauts will be gathering for a pre-launch snack and photo opportunity in the dining room of crew quarters at 5 a.m. That will be followed by a weather briefing and then suitup. The crew will head for launch pad 39B at 6:49 a.m., arriving about 20 minutes later to begin boarding Discovery. The ship's crew compartment hatch should be closed for flight around 8:30 a.m.

0815 GMT (4:15 a.m. EDT)

All continues to go smoothly in today's countdown for launch of space shuttle Discovery at 10:39 a.m. EDT. The ship's external fuel tank has been loaded with liquid oxygen and liquid hydrogen. Shortly after the fueling process began, all four hydrogen and all four oxygen main engine cutoff - ECO sensors - registered "wet" when expected. Soon thereafter, engineers sent commands to simulate a dry tank and again, all eight sensors responded properly. The simulation commands are part of NASA's strategy to detect any sensors that might fail in the wet state like hydrogen ECO sensor No. 2 did during Discovery's first launch attempt July 13. So far, all of the sensors are responding normally.

Engineers will cancel the so-called "sim dry" commands around 7:15 a.m. and let the sensors return to the wet state. At that point, the countdown computer system will make a series of checks to confirm the sensors change state as required. A second test is planned during a final hold at the T-minus 9 minute mark.

0803 GMT (4:03 a.m. EDT)

The Orbiter Closeout Crew has arrived in the White Room on the end of the Orbiter Access Arm catwalk that runs from the launch pad tower to Discovery's crew module. They will make final preparations to ready Discovery for the astronaut's arrival about two hours from now.

Also, the Final Inspection Team has begun its two-hour observations of the shuttle vehicle. They are standing atop the mobile launch platform, starting their work.

0746 GMT (3:46 a.m. EDT)

Filling of Discovery's external fuel tank with 528,000 gallons of super-cold liquid oxygen and liquid hydrogen was officially completed 3:39 a.m. EDT.

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 will be dispatched to the pad to perform their jobs. The closeout crew will ready Discovery's crew module for the astronauts' boarding in a couple of hours; and the inspection team will give the entire vehicle a check for any ice formation following fueling.

0744 GMT (3:44 a.m. EDT)

T-minus 3 hours and holding. Countdown clocks have entered a planned three-hour built-in hold in advance of today's launch of space shuttle Discovery. This is a standard hold in every shuttle countdown. However, NASA has extended it from the usual two hours to three hours to give the final inspection team more time to complete their ice and debris checks of the shuttle after fueling. The team will be sent to pad 39B to begin their inspections once fueling of Discovery is completed.

0700 GMT (3:00 a.m. EDT)

The shuttle weather officer has just revised the forecast for launch time. There is now an 80 percent chance of acceptable weather at 10:39 a.m. EDT, an improvement from the 60 percent odds given earlier.

0618 GMT (2:18 a.m. EDT)

The approximate three-hour fueling process is now passing the half-way mark. NASA is not reporting any problems with the activities to fill the external fuel tank this morning. Launch of Discovery remains targeted for 10:39 a.m. EDT.

0610 GMT (2:10 a.m. EDT)

The fuel sensors have been working trouble-free during the first 40 minutes of monitoring, NASA says.

0547 GMT (1:47 a.m. EDT)

All of the engine cutoff sensors are performing normally so far, including a successful simulation test in which the sensors were commanded to a "dry" state. During a similar test on the first launch attempt, sensor No. 2 remained stuck in a "wet" reading.

The liquid oxygen system transitioned to fast-fill at 1:40 a.m. EDT, followed four minutes later on the liquid hydrogen side. The fast-fill continues until each tank is 98 percent full. Topping then begins.

0544 GMT (1:44 a.m. EDT)

T-minus 5 hours and counting. Fueling operations continue without any problems being reported by NASA this morning.

0530 GMT (1:30 a.m. EDT)

The launch team has begun its monitoring of the engine cutoff sensors in the bottom of the liquid hydrogen tank. Throughout the countdown the sensors will be carefully watched to ensure all four are operating properly. One gave faulty readings during the first launch attempt, forcing a scrub.

Meanwhile, the liquid oxygen slow-fill started at 1:26 a.m. EDT.

0504 GMT (1:04 a.m. EDT)

The slow-fill mode started for loading the liquid hydrogen into the external tank at 1:00 a.m. EDT. Liquid oxygen slow-fill should start in about 25 minutes. The slow-fill continues until the tank is five percent full, then the fast-fill starts.

There are actually two tanks inside the shuttle's orange bullet-shaped tank. The liquid oxygen tank fills the top third of the external tank. It will be filled with 143,000 gallons of liquid oxygen chilled to minus 298 degrees Fahrenheit (minus 183 degrees Celsius). 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 (minus 253 degrees Celsius).

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.

The fueling process is being orchestrated by engineers in the safe confines of the Kennedy Space Center's Launch Control Center located about three-and-a-half miles from Discovery at launch pad 39B.

0450 GMT (12:50 a.m. EDT)

Fueling operations have begun! The chilldown thermal conditioning of the propellant lines and Discovery's internal plumbing commenced at 12:48 a.m. EDT. The chilldown preps the systems for the shock from the super-cold cryogenic liquid oxygen and liquid hydrogen fuels that will be pumped into the external tank this morning.

0444 GMT (12:44 a.m. EDT)

T-minus 6 hours and counting. The countdown has resumed from the two-hour built-in hold. We're still awaiting word on the start of fueling.

0410 GMT (12:10 a.m. EDT)

The start of fueling is expected to begin within the next half-hour. Countdown clocks are currently holding at the T-minus 6 hour mark. The count will resume at 12:44 a.m. EDT and head to the T-minus 3 hour mark where a three-hour hold is planned.

0400 GMT (12:00 a.m. EDT)

The formal "go" has been given to begin fueling operations as scheduled. NASA is not reporting any technical problems at this time.

0350 GMT (11:50 p.m. EDT Mon.)

The pre-fueling management team meeting is underway right now to give final approval for loading Discovery with propellants tonight. The latest weather forecast still predicts a 60 percent chance of acceptable conditions at the 10:39 a.m. EDT launch time.

MONDAY, JULY 25, 2005

The cocoon-like rotating service structure peeled away from space shuttle Discovery this afternoon, revealing the spaceplane on launch pad 39B as technicians made final preparations to begin pumping a half-million gallons of supercold rocket fuel into the external tank just after midnight tonight. Liftoff remains set for 10:39 a.m. EDT (1439 GMT) tomorrow.

First Lady Laura Bush is coming to Kennedy Space Center to watch the launch from the VIP viewing site at Banana Creek. She plans to visit the firing room in the Launch Control Center after liftoff.

Discovery's astronauts are asleep right now. They'll be awakened at 12:30 a.m. EDT tonight to begin launch morning activities. Departure from the crew quarters for the ride to the launch pad is scheduled for 6:49 a.m.

We will provide live play-by-play reports on the countdown starting at about 12:15 a.m. in advance of fueling operations commencing.

A detailed look at the countdown is available here.

For a look at the launch events, see our timeline here.

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

The rotating service structure appears to have completed its move. The operation took place nearly three hours later than planned after work at the launch pad fell behind schedule. Such delays are not uncommon and will not affect tomorrow's planned launch at 10:39 a.m. EDT (1439 GMT). The countdown has been in a planned built-in hold at T-11 hours since 4 a.m. this morning. The clocks will resume ticking at 5:44 p.m.

1955 GMT (3:55 p.m. EDT)

The rotating service structure rollback is accelerating now that it work platforms are a safe distance from Discovery.

1943 GMT (3:43 p.m. EDT)

The rotating service structure has started rolling away from space shuttle Discovery, exposing the orbiter for the remainder of the countdown to tomorrow's launch.

The mobile structure provides the primary access and weather protection for Discovery during its stay on the launch pad. The RSS was used for installing the payloads into the shuttle and feeding the reactants into the ship's three electricity-generating fuel cells, too.

Measuring 102 feet long, 50 feet wide and 130 feet high, the structure swings 120 degrees via hinges from the fixed launch pad tower.

Once the RSS arrives in its parked position for launch, teams at pad 39B will spend the next several hours performing final work to secure the complex for liftoff. The pad will be cleared of all personnel before operations begin to load Discovery's external fuel tank with a half-million gallons of cryogenic propellants shortly after midnight.

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

Retraction of the rotating service structure has been delayed until around 3 p.m. EDT this afternoon after launch pad workers fell behind schedule. Delays in moving the gantry-like structure are a regular occurrence.

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

"The countdown continues to proceed very smoothly with no significant issues or problems. All of our vehicle and ground systems are performing quite well," NASA test director Pete Nickolenko said this morning.

Discovery's three fuel cells were loaded with their reactants as planned yesterday, and last night the main engine system checks occurred successfully.

The countdown in is the midst of the lengthy T-minus 11 hour hold. This pause began at 4 a.m. and lasts until 5:44 p.m. EDT today.

Underway this afternoon are the orbiter and ground communications tests and loading of last-minute items into the crew module's storage lockers. The gantry-like rotating service structure enclosing Discovery is scheduled for retraction to the launch position at about 1:30 p.m. EDT. That will be followed by final closeouts of pad 39B. Fueling of Discovery's external tank is slated to begin as early as 12:15 a.m. EDT tonight.

The launch window has been modified very slightly based on the latest tracking of the international space station. Discovery's window now opens at 10:33:59 a.m. and closes at 10:44:00 a.m. EDT. The preferred launch time, when Earth's rotation carries the launch pad into the plane of the station's orbit, is 10:38:59 a.m., one second earlier than NASA's previous estimate.

Should launch be delayed 24 hours, Discovery's window will be shortened to five minutes and liftoff will be targeted for 10:11:29 a.m. The window will close at 10:16:02 a.m. The shortened window is the result of the station's orbit and a requirement to dock with the station two days after launch (flight day 3).

SUNDAY, JULY 24, 2005

NASA managers today cleared the shuttle Discovery for another launch try Tuesday, weather permitting, on a critical flight to service and resupply the international space station. The decision came after senior managers agreed on a strategy that would permit blastoff even if - and only if - the shuttle experiences a fuel sensor problem like the one that grounded the ship July 13. Read our full story.

2210 GMT (6:10 p.m. EDT)

The news conference is now underway. Discovery has been cleared for launch Tuesday morning. We'll have a complete story following the briefing on the rationale to proceed with the launch and how any problems with the engine cutoff sensors will be handled during the countdown.

2120 GMT (5:20 p.m. EDT)

Today's news conference by NASA managers is not expected to occur until 5:45 p.m. at the earliest.

2055 GMT (4:55 p.m. EDT)

The news conference has now slipped to no earlier than 5:30 p.m. as today's mission management team meeting is running longer than expected.

2022 GMT (4:22 p.m. EDT)

Today's news conference by mission managers is now not expected to take place before 5 p.m. EDT (2100 GMT).

2000 GMT (4:00 p.m. EDT)

The countdown has entered a four-hour built-in hold at the T-19 hour mark.

1540 GMT (11:40 a.m. EDT)

The shuttle Discovery's countdown remains on track today with forecasters continuing to predict a 60 percent chance of acceptable weather at launch time Tuesday. NASA's mission management team will meet this afternoon to assess the status of launch processing and to discuss the team's strategy for managing any fuel sensor problems that might crop up Tuesday. Read our full story.

1415 GMT (10:15 a.m. EDT)

Storage spheres under the payload bay lining of space shuttle Discovery will be filled with cryogenic liquid hydrogen and liquid oxygen reactants this morning as the countdown continues for Tuesday's launch.

The super-cold fluids are combined by the ship's three fuel cells to generate electricity to power onboard systems and give off drinking water as a byproduct during Discovery's planned 12-day space voyage.

NASA managers say the three-day countdown leading to liftoff at 10:39 a.m. EDT (1439 GMT) Tuesday remains on schedule and free of any technical troubles.

"Our vehicle and ground systems are continuing to perform well as we're tracking no significant issues at all," NASA test director Jeff Spaulding said this morning.

Yesterday the aft engine compartment was closed for flight and the external doors installed at 1 p.m. EDT. The so-called confidence check of the aft was completed by 9 p.m. EDT. Overnight the shuttle's navigational systems were activated and a planned four-hour hold occurred at the T-minus 27 hour mark in the countdown from 4 to 8 a.m. EDT.

Another four-hour hold is upcoming at 4 p.m. EDT when clocks reach T-minus 19 hours. In all, the count includes about 28 hours of prescribed pauses.

Once the approximate eight-hour filling of the fuel cells is completed this afternoon, the launch pad will be reopened to workers in advance of main engine computer checks.

Meteorologists are still predicting a 60 percent chance of acceptable weather Tuesday morning. The worries involve cloud cover and rainshowers over Kennedy Space Center.

The Mission Management Team will hold their Launch Minus 2 Day meeting this afternoon. A news conference will be held at the meeting's conclusion, as early as 4:30 p.m. EDT. Watch this page for further updates then.

SATURDAY, JULY 23, 2005

NASA restarted the shuttle Discovery's countdown today, pressing for a Tuesday launch after extensive troubleshooting and a wiring change that engineers hope will resolve, if not fix, a fuel sensor problem that scrapped a July 13 launch try. Read our full story.

1600 GMT (12:00 p.m. EDT)

THE COUNTDOWN HAS BEGUN! A fresh countdown has commenced for shuttle Discovery's targeted liftoff at 10:39 a.m. EDT (1439 GMT) Tuesday. Over the next three days, a comprehensive list of pre-launch activities will be performed including final testing of the ship's systems and the loading of super-cold reactants into the electricity-generating fuel cells.

The launch team is performing the countdown from the Complex 39 Launch Control Center's Firing Room 3. Controllers were called to their stations 30 minutes ago in preparation for beginning the count.

Clocks stand at T-minus 43 hours and counting. About 28 hours of built-in holds are planned leading up to the liftoff time.

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

The countdown will begin a high noon today for the second shot at launching space shuttle Discovery on the return to flight mission Tuesday morning from Kennedy Space Center.

"At this point, we're tracking no significant issues and our remaining preparations to begin the countdown are essentially complete," said NASA test director Pete Nickolenko.

"Discovery is in excellent shape as we complete the troubleshooting from the liquid hydrogen engine cutoff sensor anomaly, which caused our first launch attempt scrub on July 13."

The launch team's "call to stations" happens at 11:30 a.m. EDT this morning in Firing Room 3 of the Complex 39 Launch Control Center. The countdown clocks will start ticking a half-hour later.

The early weather forecast for Tuesday's 10:39 a.m. EDT launch time calls for a 60 percent chance of acceptable weather due to the possibility of cumulus and anvil clouds at the launch site and showers within 20 nautical miles of the shuttle runway that would be used if launch is aborted shortly after liftoff.

"Tropical Storm Franklin is currently located approximately 260 nautical miles east of Kennedy Space Center. A trough is located along the Eastern U.S., and this trough should cause Franklin to move off to the northeast. The National Hurricane Center's forecast tracks the trough northeast towards Bermuda for the next two days. With the trough to the north and Franklin to the east, winds for launch day will become light and variable at the surface and easterly at the upper levels. A sea breeze should begin to form near the T-0 time on launch day, causing a concern for developing showers. Also, since upper level winds are from the east, anvil clouds from thunderstorms off shore over the Gulf Stream are also a concern. Our primary concerns for launch are developing cumulus clouds and showers as well as anvil clouds from offshore thunderstorms," the launch weather team reported this morning.

FRIDAY, JULY 22, 2005

Astronauts endorse NASA's fuel sensor strategy
The shuttle Discovery's crew returned to the Kennedy Space Center today to prepare for blastoff Tuesday on the first post-Columbia mission. Commander Eileen Collins, making the crew's first comments on NASA plans to possibly launch the shuttle with a known fuel sensor problem, said extensive testing and analysis had given the astronauts "a lot of confidence" and "we think they've got a great plan." Read our full story.

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

Thomas' T-38 just landed on Runway 15, so all of Discovery's astronauts have safely returned to Kennedy Space Center for launch.

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

Soichi Noguchi and Stephen Robinson are climbing from their T-38 jets following arrival. Veteran astronaut Jerry Ross and Kennedy Space Center director Jim Kennedy are on hand to welcome the crewmembers.

Andy Thomas is still en route, about 20 miles out.

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

The second wave of Discovery astronauts are touching down at the Shuttle Landing Facility, joining the other four fellow crewmates at Kennedy Space Center. All seven will be reunited in a few minutes for a brief address to the news media gathered at the runway to cover this morning's arrival in very hot, humid Florida weather.

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

Riding aboard astronauts' trademark T-38 jets, Discovery's crew is arriving at Kennedy Space Center for Tueday's launch. Commander Eileen Collins, pilot Jim Kelly and mission specialists Wendy Lawrence and Charlie Camarda just touched down on KSC's three-mile runway.

Mission specialists Soichi Noguchi, Stephen Robinson and Andy Thomas are expected to arrive in about 30 minutes.

The crew flew back to their training base at Houston's Johnson Space Center earlier this week for some additional simulator runs and refresher courses given the extended launch delay.

1515 GMT (11:15 a.m. EDT)

Space shuttle Atlantis has arrived inside the Vehicle Assembly Building, two days later than planned because of a landing gear and tire pressure issues. The ship will be lifted upright and mated to the original external fuel tank and solid rocket boosters prepped for shuttle Discovery's return to flight STS-114 mission, now set for launch Tuesday. NASA decided to fly Discovery with a different tank and boosters, giving the first stack to Atlantis for the September STS-121 mission.

Once Atlantis is attached to the tank, workers will replace main engine No. 1. That powerplant's bell-shaped nozzle has a problem that forced managers to order a swapout of the engine with another.

Atlantis will roll to launch pad 39B in early August in advance of its September 9 liftoff to the space station on the second post-Columbia mission.

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

We've updated our launch window chart to include the possible August 1-4 extension.

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

As space shuttle Atlantis makes its way right now from the orbiter processing facility hangar to the Vehicle Assembly Building in preparation to launch in September, Discovery's astronauts are en route from Houston aboard T-38 training jets in advance of starting their countdown to Tuesday morning's blastoff.

0310 GMT (11:10 p.m. EDT Thurs.)

The National Hurricane Center has released its latest official track for Tropical Storm Franklin. The new path is a radical change from the predicted track issued a few hours ago, and spells good news for Florida. You can see the maps here.

Read our earlier Mission Status Center coverage.