FRIDAY, DECEMBER 6, 2002

The shuttle Endeavour's hard-luck crew was forced to pass up two more Florida landing opportunities today because of dismal weather at the Kennedy Space Center. The astronauts now are setting their sights on a landing Saturday, in Florida or California, to finally bring their marathon mission to a close after a record fourth extension day. Read our full story.

1823 GMT (1:23 p.m. EST)

Here are the latest times for landing opportunities on Saturday (all times EST):

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

215......KSC.....01:32 p.m......02:37 p.m.
216......KSC.....03:09 p.m......04:15 p.m.
217......EDW.....04:40 p.m......05:45 p.m.
218......EDW.....06:17 p.m......07:22 p.m.

1817 GMT (1:17 p.m. EST)

ANOTHER DAY IN SPACE. Weather at Kennedy Space Center won't permit Endeavour to return home today, forcing the shuttle to remain in Earth orbit for yet another day. It marks the first time in space shuttle program history that a landing has been waved off on three consecutive days.

NASA is expected to call up the Edwards Air Force Base in California for full support tomorrow, giving entry flight director Wayne Hale the option of diverting Endeavour to the West Coast if weather at Kennedy Space Center remains unfavorable.

The weather forecast for Saturday predicts a slight chance of a low cloud ceiling at KSC and acceptable conditions at Edwards.

1800 GMT (1:00 p.m. EST)

Another detailed weather briefing is expected shortly. Conditions remain dismal at Kennedy Space Center.

1717 GMT (12:17 p.m. EST)

The crew has switched Endeavour'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.

1655 GMT (11:55 a.m. EST)

Mission specialists Mike Lopez-Alegria and John Herrington have completed the work to close and latch Endeavour's payload bay doors. Next up will be transitioning the shuttle's onboard computers to the entry software package.

1651 GMT (11:51 a.m. EST)

The latest check on the weather at the Kennedy Space Center, the cloud ceiling is just 500 feet. The top of the Vehicle Assembly Building is obsecured in the clouds. The landing time forecast now calls for overcast skies at 1,500 feet.

1639 GMT (11:39 a.m. EST)

The Spaceflight Meteorology Group says the cold front that is affecting the KSC weather isn't expected to sweep through the Central Florida area until 9 or 10 p.m. tonight. But the payload bay doors will be closed and the astronauts will don their entry suits while the clouds are watched over the next couple of hours. Should flight director Wayne Hale take it down to the wire, the final "go/no go" decision point for the deorbit burn will be shortly after 2 p.m.

Here was the call to the astronauts a few minutes ago:

"What we'd like to do is have you pickup in the deorbit prep checklist wherever you left off and we're going to march down toward TIG (deorbit ignition)," radioed astronaut Duane Carey radioed from Houston. "Now the problem is, the weather is not clearing out at the Cape. The forecast is for 1,500 (feet) overcast by landing time. Howver, we're holding out some faint hope the weather will improve and just in case it does, we don't want to be unprepared. So we're going to march down through the checklist."

"Copy that," replied shuttle skipper James Wetherbee. "We're happy to march through and again, we think Wayne is the best, so we're happy to do what he wants."

1629 GMT (11:29 a.m. EST)

The decision has been made to continue with the deorbit preparations and close the payload bay doors despite very, very little hope of weather improving today. By marching on, the meteorologists can still track the weather while keeping the options open to bring Endeavour back to Earth on the final landing opportunity of the day at 3:33 p.m. EST.

NASA plans to call up the alternate landing site at Edwards Air Force Base in California on Saturday, giving entry flight director Wayne Hale the option of diverting Endeavour to the West Coast if weather at Kennedy Space Center remains unfavorable.

The weather forecast for Saturday predicts a slight chance of a low cloud ceiling at KSC and acceptable conditions at Edwards. Both sites are expected to have good weather on Sunday, should it come to that.

1614 GMT (11:14 a.m. EST)

The crew was just told that the game plan for the rest of today will be provided to them in 10-15 minutes following an upcoming weather briefing. Officials will either decide to close the payload bay doors to preserve the option to land at 3:33 p.m. today -- if the weather dramatically improves -- or scrub for the day.

1453 GMT (9:53 a.m. EST)

Here was the call to the astronauts a few minutes ago:

"The latest observation from the Cape is 900 overcast with drizzle in the area and it doesn't look good for the first rev," astronaut Duane Carey radioed the crew from Houston. "We're hoping for some breaks in the clouds for the second rev. So let's just go around again and we'll have an update for you after the next (weather) brief."

1448 GMT (9:48 a.m. EST)

The first landing opportunity today has been scrubbed. NASA will continue to monitor the weather for any signs of improvement. At the KSC runway right now it is drizzling and the overcast at 900 feet. The second and final landing option today would begin with a deorbit burn at 2:27 and touchdown on Runway 33 at 3:33 p.m. EST. However, the forecast remains very dismal.

Another weather briefing is expected in about 90 minutes.

Here are the landing opportunities for Saturday (times approximate; EST used throughout):

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

215......KSC.....01:33 p.m......02:37 p.m.
216......KSC.....03:10 p.m......04:14 p.m.
217......EDW.....04:41 p.m......05:45 p.m.
218......EDW.....06:18 p.m......07:22 p.m.

1340 GMT (8:40 a.m. EST)

Mission Control just briefed the crew on weather outlook. Like yesterday, the plan is to begin deorbit preparations but stop short of activities to close the payload bay doors for the first landing opportunity today. NASA doesn't want to have Endeavour maneuver to the door closing attitude and waste propellant unless there is a chance of acceptable weather. The doors are supposed to be swung shut just after 10 a.m. in support of a 1:57 p.m. landing.

The Saturday forecast is calling for improving conditions in Florida and fine weather at the backup landing site at Edwards Air Force Base in California. Entry flight director Wayne Hale has indicated Endeavour will land at one of the sites on Saturday.

1330 GMT (8:30 a.m. EST)

The entry team of flight controllers has received the first weather briefing of the morning and the news from the Spaceflight Meteorology Group is not overly encouraging for bring Endeavour home today. At the Kennedy Space Center runway at this moment there is a cloud ceiling at 1,100 feet and rainshowers in the area.

The forecast for the first of two landing opportunities -- with a touchdown at 1:57 p.m. EST -- calls for unacceptable low clouds at 3,000 feet and a chance of showers around the KSC landing strip. The second opportunity one orbit later -- with a touchdown at 3:33 p.m. EST -- offers a glimmer of hope that the ceilings will lift.

NASA will make a decision whether to close the payload bay doors and press ahead for the first landing attempt today or stand down and target the second one.

The backup landing site at Edwards Air Force Base in California is still not called up today.

THURSDAY, DECEMBER 5, 2002

Slim hopes dashed, NASA managers this morning ordered the shuttle Endeavour's crew to forego any landing attempts today and to remain in orbit until at least Friday because of low clouds, high winds and rain this afternoon at the Kennedy Space Center. Read our full story.

1555 GMT (10:55 a.m. EST)

ANOTHER DAY IN SPACE. After reviewing the weather forecast again, entry flight director has just made the decision to throw in the towel for today. The weather at the prime landing site at Kennedy Space Center is dominated by clouds, winds and approaching rain due to a frontal system. With virtually no chance of improving conditions, NASA made the call to keep Endeavour in space for another day.

The first landing opportunity on Friday is 1:56 p.m. EST. Conditions are expected to be better tomorrow.

1551 GMT (10:51 a.m. EST)

At least one more orbit. NASA has waved off the first of two landing opportunities today. This would give the meteorologists in Mission Control another 90 minutes to watch the weather. Should conditions somehow improve at Kennedy Space Center, Endeavour's payload bay doors would be closed around 12:30 p.m., setting up for the deorbit burn at 3:22 for landing at 4:30 p.m. EST. But frankly the weather folks are giving very little hope of acceptable landing conditions today.

1520 GMT (10:20 a.m. EST)

It is pretty well clouded over now at the Cape, winds remain gusty and a heavy line of shows and thunderstorms extend across the state to the northwest of KSC.

For those looking ahead, if today's landing opportunities are scrubbed and Endeavour stays aloft for another day, there are two entry options for KSC on Friday. The first would start with a deorbit burn at 12:51 p.m. on orbit 199 and landing at 1:56 p.m. EST. The backup opportunity is available an orbit later with the braking burn at 2:29 p.m. and touchdown at 3:33 p.m. EST.

1450 GMT (9:50 a.m. EST)

Here is some of the conversation between flight director Wayne Hale and Endeavour commander Jim Wetherbee:

"The weather is pretty bad in Florida right now, we've got winds already out of limits at the SLF (shuttle landing facility), crosswinds," Hale radioed.

"The forecast is for that to continue to be out of limits. The cold front that we've been watching the last couple of days has slowed down a little bit and it is likely that we will have showers and possibly even thunderstorms in the vicinity of the SLF at landing time, in addition to the winds, and there will be several low cloud decks to talk about as we get closer.

"But the weatherman has told us there is a possibility (the front) could slow down, that conditions could improve, a slim possibility. So we're going to watch it for another hour or two. What I'd like you guys to do is to continue to prepare. I would not fluid load, I would not do anything that you couldn't back out of fairly easily because I think the probability is fairly low. But we want to keep the option open in case things break our way."

"Thanks for the update, we really appreciate it," commander James Wetherbee replied. "Your job is the toughest one, I think, but I've always trusted you and you know best. So we'll execute. Thanks a lot."

"Thanks, Jim, we'll do what we can to get you down today, but only if it's safe to do so."

1445 GMT (9:45 a.m. EST)

Mission Control has revised to the deorbit and landing times for today. The first attempt begins with a deorbit burn at 1:45 p.m. for touchdown at Kennedy Space Center at 2:52 p.m. EST. The follow orbit has a deorbit burn opportunity at 3:22 p.m. and landing at 4:29 p.m. EST.

The weather forecast for Friday is better but still not perfect.

1435 GMT (9:35 a.m. EST)

Entry flight director Wayne Hale just radioed Endeavour commander Jim Wetherbee with news that pre-landing activities will continue over the next hour to give the weather team more time to monitor conditions in Florida. The crosswinds are already out of limits at the shuttle runway. The forecast is predicting low clouds and rain as the day rolls on. There is only a slim hope that the weather would permit a landing today, if the frontal system slows down.

So the next decision point will be prior to closing Endeavour's payload bay doors. Due to limited onboard propellant, NASA only has four or five more deorbit opportunities available. If the weather situation looks hopeless today, Mission Control doesn't want to waste the fuel. The propellant budget is consumed for door closure and afterward.

The backup landing site at Edwards Air Force Base in California has not been called up for support today.

1403 GMT (9:03 a.m. EST)

This morning's weather forecast being issued by the Spaceflight Meteorology Group is calling for a low-cloud ceiling at 7,000 feet, showers and thunderstorms within 30 miles of the runway and winds slightly out of limits, all of which would be constraints against bringing Endeavour home to Kennedy Space Center.

1340 GMT (8:40 a.m. EST)

The entry team of flight controllers are taking over in Mission Control. The first detailed weather briefing of the morning is expected around 9:15 a.m. EST. After that, officials will decide whether to begin landing preparations today or keep Endeavour in space until Friday.

The crew was awakened today by a recording of "Hotel California" beamed up from Mission Control.

"We're happy to stay in this beautiful hotel for a few more days if we need to," astronaut Michael Lopez-Alegria called.

"Roger that," said astronaut Joan Higginbotham from mission control.

"And hopefully, we'll be checking into the Hotel Florida," quipped commander James Wetherbee.

"We'll see if we can get some reservations for you."

If NASA decides to press ahead with landing attempts today, the payload bay doors will be closed at 11:09 a.m., setting up for the first of two deorbit opportunities of the day to bring Endeavour down at Kennedy Space Center. A deorbit burn on orbit 184 would occur at 1:49 p.m. with touchdown at 2:54 p.m. EST. The second rev is one orbit later with a burn at 3:26 p.m. and landing at 4:30 p.m. EST.

Forecasters had predicted unfavorable weather this afternoon as a weather system moves through. But at the moment, it is a pretty nice morning here in Central Florida.

WEDNESDAY, DECEMBER 4, 2002

Entry flight director Wayne Hale, faced with deteriorating weather at the Kennedy Space Center, called off a second attempt to land the shuttle Endeavour today at the Kennedy Space Center and delayed re-entry at least 24 hours. NASA's Spaceflight Meteorology Group is predicting solidly "no-go" conditions Thursday, raising the prospect of a delay to at least Friday and possibly longer. Read our full story.

2056 GMT (3:56 p.m. EST)

NO LANDING TODAY. With unfavorable landing weather conditions at Kennedy Space Center today, space shuttle Endeavour will stay in space for at least another day. With even worse weather expected on Thursday, flight controllers will review the situation in the morning before deciding whether to attempt any opportunities tomorrow or scrub until Friday. The shuttle has enough supplies to safely remain in space for a few more days.

2045 GMT (3:45 p.m. EST)

Coming up on a final decision on the fate of today's attempt to bring Endeavour home.

2030 GMT (3:30 p.m. EST)

The latest check on the Spaceflight Meteorology Group's forecast shows low clouds expected over the runway at the 5:26 p.m. EST, which would be unacceptable for a shuttle landing.

2024 GMT (3:24 p.m. EST)

NASA astronaut Kent Romginger, flying the Shuttle Training Aircraft, is continuing his weather reconnaissance flights to evaluate the clouds to the south of Kennedy Space Center. About 35 minutes remaining until the "go/no go" decision is expected on the deorbit burn for this final landing opportunity of the day.

2011 GMT (3:11 p.m. EST)

Endeavour's vent doors are now being closed.

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

The deorbit burn time has been revised a bit. The three-minute, four-second firing of the shuttle's two orbital maneuvering system engines would begin at 4:19:05 p.m. EST. Landing would occur at 5:26 p.m. EST, about sunset at Kennedy Space Center. However, that all assumes the weather improves at the Cape.

1950 GMT (2:50 p.m. EST)

Looking down the road, the forecast for Florida looks lousy tomorrow as that weather system moves through the Sunshine State. It had been expected that conditions would greatly improve on Friday. However, the latest from the Spaceflight Meteorology Group is now calling for the chance of showers and low clouds on Friday. So given the uncertainty, Wayne Hale decided it was worth at least given this upcoming landing opportunity a try in case the clouds do improve over the next hour.

1943 GMT (2:43 p.m. EST)

The decision has been made to continue with preparations for the next deorbit burn opportunity in hopes the Florida weather picture improves. Although it is far from certain that conditions will become acceptable, entry flight director Wayne Hale has decided to give it a run. A final "go/no go" decision to brake from orbit is expected in about an hour.

1937 GMT (2:37 p.m. EST)

The current observed conditions at the Kennedy Space Center runway are "no go" at this moment due to a broken deck of clouds at 6,000 feet.

1927 GMT (2:27 p.m. EST)

Entry flight director Wayne Hale will be receiving another weather briefing shortly before deciding whether its worth going through the motions for the second landing opportunity or just scrub entirely for the day. The clouds have been building quite quickly this afternoon around Central Florida.

Endeavour has enough propellant to hold attitude for six deorbit opportunities. One has now been used. So if the weather is unlikely to improve today, Hale could opt to make the call now to keep Endeavour in space for another 24 hours and bypass the second landing opportunity of the day.

1920 GMT (2:20 p.m. EST)

ANOTHER ORBIT! Worried about low clouds obscuring commander Jim Wetherbee's view of the runway, Mission Control has scrubbed this first of two landing opportunities available today to bring Endeavour home at Kennedy Space Center.

The shuttle will stay in space for another 90-minute orbit of Earth. Should the weather improve, the shuttle could perform a deorbit burn at 4:20 p.m. EST for a sunset landing in Florida at 5:26 p.m. EST.

If the weather doesn't cooperate this afternoon, Endeavour will remain aloft for another day. With plenty of onboard consumables for several extra days in space, NASA has not called up the backup landing site at Edwards Air Force Base in California.

1916 GMT (2:16 p.m. EST)

The crew has been told to hold off on closing the vent doors and maneuvering to the deorbit attitude.

1915 GMT (2:15 p.m. EST)

Weather pilot Kent Rominger says the clouds to the southwest is broken and even overcast is some spots. The clouds are moving in the direction of the Kennedy Space Center. Entry flight director Wayne Hale is pondering that information and will soon have to decide whether Endeavour can brake from orbit at 2:41 p.m. EST or remain in space for at least another orbit.

1908 GMT (2:08 p.m. EST)

Entry flight director Wayne Hale has polled his team in Mission Control -- with the exception of the weather team -- to ensure everything on the technical side is ready for the deorbit burn. No problems reported.

Again, there are some clouds that have recently popped up to the southwest of the runway that are of concern. The weather aircraft has been dispatched to examine the clouds. The deorbit burn is just over a half-hour away.

1905 GMT (2:05 p.m. EST)

Some clouds have popped up to the southwest of the Shuttle Landing Facility. Meteorologists are now trying to determine their thickness and expected location at the time of Endeavour's homecoming. NASA astronaut Kent Rominger is flying the Shuttle Training Aircraft around the landing site today for weather reconnaissance. He will be taking a look at these clouds.

1902 GMT (2:02 p.m. EST)

Pilot Paul Lockhart 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 prior to the deorbit burn.

1900 GMT (2:00 p.m. EST)

A steering check of the Endeavour's twin orbital maneuvering system engines on the tail of the shuttle is now beginning. The deorbit burn engine firing will begin at 2:40:53 p.m. EST and last for three minutes and three seconds. The burn will slow the ship by over 300 feet per second.

The braking will drop the shuttle from orbit, putting Endeavour on course to fall back into the atmosphere for the hour-long glide to the Kennedy Space Center landing site. Touchdown is expected at 3:48 p.m. EST on Runway 15.

Clouds around Central Florida are still being watched closely. A final "go/no go" call for the deorbit burn is expected within the half-hour.

1841 GMT (1:41 p.m. EST)

Now one hour from the deorbit burn. The crew is donning the entry suits and performing their "fluid loading" protocol of drinking large amounts of fluids to assist in the readaptation to Earth's gravity.

1833 GMT (1:33 p.m. EST)

Forecasters have removed the chance of showers around the runway this afternoon at Kennedy Space Center. However, there is still the chance of low clouds at 6,000 feet. But optimism remains that the weather will cooperate and allow Endeavour to land as scheduled today.

1815 GMT (1:15 p.m. EST)

The commander and pilot are currently scheduled to begin suiting up in the day-glow orange launch and entry suits and strapping into their seats. The rest of the crew are slated to begin suiting up in a little more than a half an hour.

The "go/no go" decision for the deorbit burn by entry flight director Wayne Hale is about an hour away.

1750 GMT (12:50 p.m. EST)

Deorbit preparations are continuing with no technical issues and an improving weather forecast. Although the weather officials in Mission Control have not given their final OK for landing, and that isn't scheduled for another 90 minutes or so, conditions are "trending" in the right direction.

Clocks are counting down to the planned 2:41 p.m. EST ignition of a three-minute firing by Endeavour's twin orbital maneuvering system engines to drop from orbit. Landing is still set for Kennedy Space Center's Runway 15 at 3:48 p.m. EST.

1702 GMT (12:02 p.m. EST)

Endeavour's clam-shell-like payload bay doors have been closed and locked in preparation for today's fiery descent into Earth's atmosphere and 3:48 p.m. EST landing at Kennedy Space Center.

Mission Control will soon give commander Jim Wetherbee a "go" to transition Endeavour'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 Endeavour will be maneuvering to a new orientation in space to improve the communications link with NASA's orbiting data relay satellites.

1645 GMT (11:45 a.m. EST)

The weather around Central Florida is favorable at this hour and meteorologists say they may be able to remove the chance of a low cloud ceiling and rainshowers from the forecast for landing time. A final "go/no go" decision for Endeavour's deorbit burn to brake from orbit is expected around 2:20 p.m. EST.

Upcoming in the next few minutes, the astronauts will be closing the shuttle's payload bay doors.

1538 GMT (10:38 a.m. EST)

The first detailed weather briefing of the day has been given to entry flight director Wayne Hale in Mission Control. Although there is still the possibility of low clouds and rainshowers around the Kennedy Space Center landing strip, there is optimism that the weather will cooperate to permit Endeavour to return home at 3:48 p.m. EST today.

WEDNESDAY, DECEMBER 4, 2002

While there's a chance of rain and even thundershowers near the Kennedy Space Center this afternoon, NASA Spaceflight Meteorology Group is predicting a 70 percent chance of acceptable weather for the shuttle Endeavour's planned landing. Touchdown on runway 15 is targeted for 3:48 p.m. EST. Read our full story.

TUESDAY, DECEMBER 3, 2002

Shuttle commander James Wetherbee says his crew has more than enough food, fuel and other supplies to remain in orbit a few extra days if the weather doesn't permit an on-time landing Wednesday. But just in case, the shuttle skipper said the crew is foregoing second helpings. Read our full story.

MONDAY, DECEMBER 2, 2002

With pilot Paul Lockhart at the controls, the shuttle Endeavour undocked from the international space station Monday, leaving a fresh three-man crew behind and ending seven days of work to install and activate a new solar array truss segment. Later in the day, the shuttle launched two tiny picosats connected by a 50-foot tether. Read our full story.

2205 GMT (5:05 p.m. EST)

The MEPSI picosats -- two tiny satellites adjoined by a tether -- have been launched from the payload bay of space shuttle Endeavour while orbiting 250 miles above the Pacific Ocean.

2115 GMT (4:15 p.m. EST)

Deployment of the MEPSI payload from Endeavour is scheduled for 5:02 p.m. EST. From the NASA press kit, here is an overview of MEPSI:

The MEMS-based PICOSAT Inspector (MEPSI) experiment series will conduct its third space test mission as two miniature satellites are released on orbit from NASA's STS-113 shuttle mission. The tethered satellite pair, each measuring 4" x 4" x 5", will be released from a specialized spring-loaded launcher assembly mounted on the sidewall of the space shuttle Endeavour en-route from the International Space Station (ISS).

Funded by the Defense Advanced Research Projects Agency (DARPA), this "PICOSAT" mission represents a significant step forward in the development of an on-board autonomous inspection capability being directed by the Air Force Research Laboratory (AFRL) Information Directorate located in Rome, N.Y. Researchers at the Information Directorate envision MEPSI enhancing satellite command and control operations by providing active on-board imaging capability to assess spacecraft damage, monitor launch and deployment sequences, and augment servicing operations. This will provide the foundation for a rapid feedback capability for spacecraft operators to detect and respond to anomalies while maintaining continual service to their users, and enable ultimate spacecraft longevity.

MEPSI is integrated and flown under the direction of the Department of Defense Space Test Program. Third in a series of incremental flight experiments (two previous flights, one in February 2000 and the other in September 2001, were deployed from the Air Force's new OSP-Minotaur launch vehicle), the success of this mission also demonstrates a new capability for NASA's shuttle program that allows for PICOSAT type payloads to be flown on virtually any shuttle mission.

The two PICOSATs, built by The Aerospace Corporation and the NASA Jet Propulsion Laboratory (JPL), are adjoined by a 50-foot non-conducting tether to facilitate detection by Earth-based radar and keep them in radio range of each other. The objectives of the minimum three-day mission include:

• Demonstration of a "new" 4-inch form factor launcher assembly approved for use in the shuttle cargo bay;
• Establish communications and data exchange between the two PICOSATs and the ground station;
• Exercise on-board Microelectromechanical Systems (MEMS) inertial measurement system;
• Implementation of MEMS RF switches in transmit/receive operation along the communications critical path;
• Improved RF transmit power.

Among the major challenges of this mission are to implement the greatest amount of science within a fairly minimal power budget.

In addition to the primary mission of realizing the MEPSI concept, the PICOSATs serve as a low-cost test bed for progressive development and insertion of micro- and nanotechnologies into radically different space systems. The PICOSAT platform serves as an ideal means for proving revolutionary technologies and concepts without breaking the bank.

2102 GMT (4:02 p.m. EST)

The final separation maneuver by Endeavour has been completed and the shuttle is now quickly departing the vicinity of the space station.

Coming up in about an hour, small Air Force picosat payload will be ejected from the payload bay of Endeavour.

2050 GMT (3:50 p.m. EST)

Under the control of pilot Paul Lockhart, Endeavour has begun maneuvering from a point in front of the station to a point directly above the complex where the final separation engine firing will be performed.

2038 GMT (3:38 p.m. EST)

Now 420 feet between Endeavour and the station.

2031 GMT (3:31 p.m. EST)

Separation distance now 230 feet.

2024 GMT (3:24 p.m. EST)

The shuttle is now 158 feet away from the station, continuing to move out in front of the orbiting outpost.

2008 GMT (3:08 p.m. EST)

Endeavour is now 20 feet from the station, backing away at about 0.1 feet per second. The shuttle is headed to a point about 450 feet away to begin a quarter-lap flyaround of the station.

2005 GMT (3:05 p.m. EST)

UNDOCKING! While passing into an orbital sunrise over northern Australia, Endeavour has undocked from the international space station after a week-long visit that mounted the Port 1 truss the complex and rotated the Expedition resident crews. The shuttle is ferrying the Expedition 5 crew back to Earth after nearly six months in orbit. Landing at Kennedy Space Center is scheduled for Wednesday.

2003 GMT (3:03 p.m. EST)

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

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

Five minutes from undocking. The steering jets on Endeavour 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 Paul Lockhart will fire Endeavour's thrusters to continue the movement away.

1953 GMT (2:53 p.m. EST)

Now 12 minutes from the scheduled departure of Endeavour from the space station. The undocking is expected to occur about 250 miles above the northwestern coast of Australia.

1946 GMT (2:46 p.m. EST)

Mission Control has given the astronauts a "go" for undocking.

1944 GMT (2:44 p.m. EST)

Power-up of the docking mechanism in Endeavour's payload bay has occurred.

1940 GMT (2:40 p.m. EST)

All is in readiness for today's undocking of space shuttle Endeavour from the international space station about 25 minutes from now. The station's solar arrays have been positioned edge-on to the shuttle to ensure they are no damaged from Endeavour's thruster plumes. In addition, the shuttle-station stack has been maneuvered to the proper undocking attitude.

1730 GMT (12:30 p.m. EST)

The shuttle and station crews have said their farewells and are now in the process of the closing the various hatches between the two spacecraft. Undocking remains set for 3:05 p.m. EST.

1600 GMT (11:00 a.m. EST)

The Endeavour astronauts are preparing to undock from the international space station this afternoon, leaving a fresh three-man crew behind and bringing the lab's fifth full-time crew home after six months in space. Read our preview story.

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

The crews of Endeavour and the International Space Station Sunday got ready to say goodbye to one another, checking out tools that will be used during undocking of the two spacecraft on Monday. They also configured and stowed spacesuits used in the mission's three spacewalks. Crewmembers got some afternoon time off to relax and talk via radio with family members.

Sunday morning Endeavour Commander Jim Wetherbee initiated a series of firings of Endeavour's thrusters to raise the station's altitude by about 2.8 statute miles. This was the third reboost of the flight and left the ISS almost 61Ž2 miles higher than it was when the shuttle docked on Nov. 25. The station's average altitude is now about 247 miles.

Shuttle crewmembers, Wetherbee, Pilot Paul Lockhart, Mission Specialists Michael Lopez-Alegria and John Herrington, and Expedition 5's NASA ISS Science Officer Peggy Whitson, her Expedition 6 successor Don Pettit and Expedition 6 Commander Ken Bowersox, spoke with representatives of Indian Country Today and Native America Calling radio network.

Transfer activities wound down, with the crew wrapping up movement of supplies, equipment and experiments between the two spacecraft. Endeavour brought more than 2,500 pounds of material to the station in the shuttle's crew compartment.

During the afternoon, Pettit and Whitson did additional troubleshooting on the Microgravity Science Glovebox (MSG) in the station's U.S. laboratory Destiny. The glovebox allows experiments with fluids, flame, particles or fumes to be performed in an enclosed environment. The MSG's power distribution and conversion box failed Nov. 20. The box will be returned to Earth aboard Endeavour, leaving the MSG inactive.

Handover talks continued between the Expedition 5 crew, Commander Valery Korzun, Whitson and cosmonaut Sergei Treschev, and Expedition 6 crewmembers Bowersox, Cosmonaut Nikolai Budarin and Pettit.

Hatches between the two spacecraft are to be closed about 12:15 p.m. EST Monday, with Endeavour undocking from the station about 3:05 p.m. near the west coast of Australia after a pass over the Indian Ocean. Landing is scheduled for Wednesday afternoon at Kennedy Space Center.

SUNDAY, DECEMBER 1, 2002
0400 GMT (11:00 p.m. EST Sat.)

In one of the more challenging space station assembly spacewalks to date, two astronauts managed to accomplish all of their primary objectives Saturday even though problems moving the station's $290 million robot arm transporter prevented them from using the Canadarm2 space crane as originally planned. Read our full story.

0227 GMT (9:27 p.m. EST Sat.)

Repressurization of the Quest airlock began at 9:25 p.m. EST, marking the end of another successful spacewalk in the construction of the international space station. Today's excursion lasted exactly seven hours.

0216 GMT (9:16 p.m. EST Sat.)

The spacewalkers are back in the airlock, getting ready to close the hatch. The EVA end time will be marked with repressurization.

0148 GMT (8:48 p.m. EST Sat.)

Clean up activities are underway in preparation for the spacewalkers returning to the airlock to complete today's EVA.

0125 GMT (8:25 p.m. EST Sat.)

Now six hours into the spacewalk. Lopez-Alegria has been approval to add four SPDs to the pump module of the P1 truss. Herrington is still working on the P1 radiator system launch locks.

0100 GMT (8:01 p.m. EST Sat.)

The spacewalk is wrapping up. Lopez-Alegria is finishing the activities with Flex Hose Rotary Coupler quick-disconnects and Herrington is completing the line connections with the nitrogen and ammonia tank assmeblies. Herrington will then check some launch locks are properly configured on the P1 radiator system.

Mission Control is still working some issues with mobile transporter at site 7. Keep alive power has been routed to the transporter. The decision has been made to stay there overnight -- not moving back to site 4 tonight.

0011 GMT (7:11 p.m. EST Sat.)

Lopez-Alegria is now moving to the S1 truss to install four SPDs on Flex Hose Rotary Coupler quick-disconnects. Herrington will be focused on the Ammonia Tank Assembly work.

0001 GMT (7:01 p.m. EST Sat.)

The spacewalk continues successfully, now passing the 4 1/2 hour mark. The astronauts are still to work through a few more SPD installations and the routing of umbilicals to link the Ammonia Tank Assembly on the P1 truss to ammonia lines in the station's cooling system and cables from the Nitrogen Tank Assembly to the Ammonia Tank Assembly.

SATURDAY, NOVEMBER 30, 2002
2352 GMT (6:52 p.m. EST)

Flight controllers report the mobile transporter is finally locked down and secured at the worksite 7 on the far end of P1.

2330 GMT (6:30 p.m. EST)

Lopez-Alegria is now preparing to reconfigure cables on the Main Bus Switching Units which will allow power to be routed to future port-side trusses.

2306 GMT (6:06 p.m. EST)

While Herrington finishes the last SPD on the Radiator Beam Valve Modules, Lopez-Alegria is beginning the next job of this EVA -- to reconfigure the Squib Firing Unit, a pyrotechnic device designed to release the P1 truss radiator panels when they are deployed next year.

2251 GMT (5:51 p.m. EST)

Mission Control reports there 15 SPDs installed on the P1 radiator areas, three more to go. The clamp-like devices ensure that the quick-disconnect fittings in the station's ammonia coolant lines can be released. It was discovered there is a design flaw that allows some leakage in the fittings, which would cause a pressure build-up over time and difficulty for astronauts to disconnect the lines in the future.

2225 GMT (5:25 p.m. EST)

Now three hours into today's spacewalk. Nine of the 18 Spool Positioning Devices have been installed on the quick-disconnects of ammonia cooling lines for the P1 truss Radiator Beam Valve Modules.

2211 GMT (5:11 p.m. EST)

The transporter has now reached its destination -- worksite 7 along the space station's truss backbone on the P1 segment. It will now be latched into position. It does not appear the station's robotic arm will step back onto the transporter base during this spacewalk.

2201 GMT (5:01 p.m. EST)

The mobile transporter is now in motion! After being stalled for 4 1/2 hours due to an obstruction between the railcar and the UHF antenna on the P1 truss, the transporter is moving the remaining 10 feet to worksite 7.

Meanwhile, the spacewalkers are hard at work installing the various SPDs on the P1 truss cooling lines associated with the Radiator Beam Valve Modules.

2125 GMT (4:25 p.m. EST)

In a rearrangement of spacewalk activities, the spacewalkers are going to work together to install many SPDs on the Radiator Beam Valve Modules of the P1 truss. This three-hour job was to be performed by Herrington riding on the end of the station's arm. But without the transporter at site 7, the arm has not moved back into position to support the EVA. So this work will have to be done 'free floating'.

2115 GMT (4:15 p.m. EST)

Mission Control is getting ready to again command the mobile transporter to move now that the track is clear.

2055 GMT (3:55 p.m. EST)

Now 90 minutes into today's planned 6 1/2-hour spacewalk. Herrington is working to hookup connectors between the now-deployed UHF antenna and station. Lopez-Alegria has completed the SPD installations between Z1 and Destiny. His next area of work will be the heat exchanger on the hull of Destiny. He will have to remove a section of shielding from the lab's exterior to gain access for the installation of two SPDs.

2047 GMT (3:47 p.m. EST)

The UHF antenna on the nadir side of the P1 truss has been deployed by spacewalker John Herrington. Initial efforts to deploy the antenna were unsuccessful because it was bound up at one of the retention points. The antenna, which has been scheduled for deployment during a spacewalk by the Expedition 6 crew next month, apparently was the obstruction in the path of the mobile transporter today.

2035 GMT (3:35 p.m. EST)

After releasing three bolts and a retention pin, the UHF antenna should have deployed. But it has not rotated free. Mission Control believed the transporter could be holding the antenna but Herrington doesn't think that is the problem.

2010 GMT (3:10 p.m. EST)

Herrington says the Interface Umbilical Assembly of the transporter is bumping into the UHF antenna on P1. The UHF antenna is currently stowed in its launch position. So Herrington is going to deploy that communications antenna to clear it from the path of the mobile transporter. Deployment of the antenna was considered a get-ahead task -- a bonus activity if time was available during this spacewalk.

Meanwhile, Lopez-Alegria has completed the SPD work between Z1 and P6 trusses. His next focus will be installing two SPDs on lines between Z1 and the Destiny module.

2002 GMT (3:02 p.m. EST)

Herrington reports that part of the mobile transporter's umbilical assembly may be hung up, causing the problem today in driving the car down the station's tracks.

1957 GMT (2:57 p.m. EST)

John Herrington is now beginning his visual inspection of the mobile transporter to determine what caused the halt during movement down the tracks.

1952 GMT (2:52 p.m. EST)

Mike Lopez-Alegria is now getting to work at the junction between the Z1 and P6 trusses, installing two Spool Positioning Devices. Lopez-Alegria's last flight -- STS-92 in 2000 -- launched Z1 to the space station.

1943 GMT (2:43 p.m. EST)

Spacewalker John Herrington will be asked to perform an inspection around the mobile transporter to give ground controllers additional insight into what is keeping the railcar from driving the final 10 feet to its planned worksite to support today's spacewalk. Possible obstructions range from one of keel pins stowed in the frame work of the P1 truss to shrouds or blankets or cable guides associated with the transporter.

Without the transporter positioned at a worksite -- it is current stuck in between sites 6 and 7 -- the station's robotic arm won't step off the Destiny module to return to the mobile base system on the transporter. The spacewalkers had planned to use the arm as a platform to stand on from worksite 7 during installation of some Spool Positioning Devices today.

1925 GMT (2:25 p.m. EST)

Today's spacewalk by Mike Lopez-Alegria and John Herrington has begun. The two Endeavour astronauts switched their spacesuits from station power to internal batteries at 2:25 p.m. EST to begin the planned 6 1/2 hour EVA.

The main objective today is the installation of 33 clamp-like Spool Positioning Devices on quick-disconnect fittings of fluid lines around the station.

1920 GMT (2:20 p.m. EST)

The airlock has reached vacuum. However, the spacewalkers have not switched their suits to internal battery power, which marks the official start time of the EVA.

1914 GMT (2:14 p.m. EST)

Commands are being prepared to back the space station's transporters from its current stalled position between worksites 6 and 7 to the worksite 4. But a final decision has not been made to execute the commands. Officials are debating whether the spacewalkers should inspect the tracks before any further movements are made.

The spacewalk has not started.

1910 GMT (2:10 p.m. EST)

Flight controllers are studying the option of backing up the transporter to get free of the obstruction.

1903 GMT (2:03 p.m. EST)

After switching the backup drive unit, efforts to move the mobile transporter have failed. So it is now believed the transporter is indeed hung up on some obstruction on the tracks.

1857 GMT (1:57 p.m. EST)

Pressure in the airlock is holding at 5 psi -- the point when suit and communications checks are performed before going to vacuum. Meanwhile, ground engineers are now looking to start a backup drive unit on the mobile transporter in hopes of getting the flatcar to its worksite on the far end of the P1 truss.

1842 GMT (1:42 p.m. EST)

The "go" has been given to start depressurizing the airlock.

1835 GMT (1:35 p.m. EST)

Mike Lopez-Alegria and John Herrington are suited up in the airlock waiting for depressurization to vacuum for the start of today's spacewalk. Mission Control is revising some of the procedures for today's excursion as a result of the mobile transporter stopping short of its intended worksite. Officials will have the spacewalkers move the CETA carts away from the transporter in order to do a thorough inspection of the transporter tracks.

1810 GMT (1:10 p.m. EST)

Engineers are looking at switching the mobile transporters to a backup power controller. It is still not clear what caused the transporter to stop in its tracks a little while ago. What impact this will have on today's spacewalk remains up in the air.

1732 GMT (12:32 p.m. EST)

Flight controllers are currently evaluating the possibility that the mobile transporter snagged on something during its trip down the station's tracks, causing the halt. Another scenario is a momentary drop out in data prompted the onboard software to stop the transporter's motion as a safety precaution. The transporter remains stalled about 10 feet short of the worksite 7.

Meanwhile, spacewalk preparations were halted to allow one of Lopez-Alegria's boot inserts to be adjusted. That work has been completed to give the astronaut more comfort.

1700 GMT (12:00 p.m. EST)

The international space station's $190 million mobile transporter, a motorized flat car designed to carry the lab's robot arm to various work sites on the station's huge solar array truss, began inching its way to a work site on the far end of the new P1 truss in prapration for today's spacewalk. But after crossing over onto P1, the transporter unexpectedly stopped about 10 feet short of its destination. Read our full story.

1540 GMT (10:40 a.m. EST)

Mike Lopez-Alegria and John Herrington are gearing up for their third and final spacewalk today, a planned six-and-a-half-hour excursion to complete the outfitting and activation of a new $390 million solar array truss segment. The spacewalk, the 49th devoted to space station assembly and maintenance, is scheduled to begin around 2:20 p.m. EST. Read our full spacewalk preview story.

FRIDAY, NOVEMBER 29, 2002
2120 GMT (4:20 p.m. EST)

During a brief change-of-command ceremony today, outgoing Expedition 5 commander Valery Korzun formally turned over the international space station to Expedition 6 commander Kenneth Bowersox, a veteran space shuttle commander with four previous flights to his credit. Read our full story.

0053 GMT (7:53 p.m. EST Thurs.)

Mission Control now says the repress began at 7:46 p.m. EST, a minute earlier than officials had initially said.

0048 GMT (7:48 p.m. EST Thurs.)

The Quest airlock began repressurizing at 7:47 p.m. EST, signaling the end of today's spacewalk by Mike Lopez-Alegria and John Herrington. The third and final EVA of Endeavour's mission is planned for Saturday.

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

The outer hatch on the airlock is now being closed and locked. The spacewalk conclusion will be marked then the airlock repressurization starts.

0025 GMT (7:25 p.m. EST Thurs.)

Clean up activities are continuing as the spacewalkers put away their tools and equipment before calling it a day. All in all, another successful EVA that completed all the planned tasks.

THURSDAY, NOVEMBER 28, 2002
2350 GMT (6:50 p.m. EST)

Spacewalking astronauts have placed the CETA cart on the rail tracks of the S1 truss, completing its relocation. The crew will start cleaning up now and preparing to complete this EVA, which has passed the five-hour mark.

2320 GMT (6:20 p.m. EST)

The CETA cart has been removed from P1 for the lengthy ride to S1.

2310 GMT (6:10 p.m. EST)

The spacewalk has been proceeding smoothly. The crew was have completed the relocation of the other keel pin. Activities are now underway for the much-anticipated movement of the CETA cart from the P1 to the S1 truss.

Herrington, anchored to the end of the station's robot arm, will manually hold the 600-pound CETA cart while the arm, operated by space station science officer Donald Pettit and commander Kenneth Bowersox, swings him through a sweeping 180-degree arc to the opposite side of the truss.

The cart must be moved before the third spacewalk of the flight to permit the Canadarm2's mobile transporter to move from its current location at worksite 4, on the front of the central S0 truss, to worksite 7 on the far end of P1, where it will be needed to complete EVA-3 activities.

"One of the neat things I get to do at the end of EVA-2 - this will probably be the high point of all the EVAs for me - is to climb on board the robotic arm with Don at the controls," Herrington said. "And I'll be taking the CETA cart from the left side of station to the right side of station.

"I'll lift it off, we'll back away from the truss a little bit, then Don will put the arm through a maneuver that will take me completely past the tail of the shuttle and back up around to the right side of the station where we'll move it back in slowly, with Mike guiding me, and we'll put it back onto the rails. So that's going to be a real exciting time, I'll get to see the station from a pretty neat perspective."

But Pettit said the drama will be a strictly slow-motion affair.

"Nothing like this happens really fast," he said. "I mean if you sat there and watched the arm move, you've got to blink a few times to see whether it's really moving. So we're not going to be trying to set any world records here. It takes about 20 minutes to do this trajectory, so there'll be plenty of time to run off to the refrigerator and grab another soft drink."

2210 GMT (5:10 p.m. EST)

The other keel pin has been unbolted. Spacewalkers are now moving it to the stowage location. We will pause our updates here for a little while as we cover the Ariane 5 launch.

2157 GMT (4:57 p.m. EST)

The mating of connectors to WETA has been finished, completing activities with the new wireless video antenna. The port keel pin relocation is now the focus for both spacewalkers.

2148 GMT (4:48 p.m. EST)

The attachment system on the end of P1 has been checked out. The P3/P4 segment will be mounted to the outboard end of P1 on a later shuttle mission. Working is now beginning to unbolt the port keel pin.

2138 GMT (4:38 p.m. EST)

Just over three hours into today's spacewalk. Mission Control has given the spacewalkers a "go" to hook up cables from the station to the WETA antenna, which has been bolted to P1. The EVA remains about 50 minutes ahead of schedule.

2134 GMT (4:34 p.m. EST)

Both spacewalkers are now working together to bolt the WETA support beam to the P1 truss.

2124 GMT (4:24 p.m. EST)

While Lopez-Alegria continues work on the P1 WETA installation, Herrington has moved to the outer end of the P1 truss to check the Segment-to-Segment Attachment System.

2112 GMT (4:12 p.m. EST)

Installation is underway of another WETA antenna for relaying the "helmetcam" video from spacewalkers to the space station. The crew installed a Wireless video system External Transceiver Assembly (WETA) on Tuesday to the Unity node; today's work is mounting an antenna to the end of P1.

2058 GMT (3:58 p.m. EST)

The starboard keel pin assembly relocation work has been completed. The spacewalkers are now running about 50 minutes ahead of their timeline, NASA reports, with virtually no snags experienced today.

2055 GMT (3:55 p.m. EST)

With Lopez-Alegria aboard, Herrington propelled the CETA cart a short distance down the tracks of the P1 truss so Lopez-Alegria could insert the keel pin in its new stowage home. The pin structure will be bolted, allowing the spacewalkers to move on to the next task -- mounting a new antenna assembly to P1.

2046 GMT (3:46 p.m. EST)

The no-longer-needed starboard keel pin launch support strut has been unbolted from the P1 truss by the spacewalkers. The V-shaped structure will be carried to another spot on P1 and stuff inside the truss for its stowage.

2030 GMT (3:30 p.m. EST)

Next up will be the removal and stowage of the first keel pin on the P1 truss. There are two keel pins, both of which will be located today, from the face of the truss to inside the structure's framework. Here's the preview:

Herrington and Lopez-Alegria, the latter on the CETA cart, move on to P1's starboard keel pin. Lopez-Alegria sets the CETA brakes, and at the worksite releases the top keel pin bolt, rotates the keel pin, then reinstalls the bolt. He then removes the lower keel pin bolt, frees the keel pin and reinstalls the bolt.

Herrington moves the CETA along with Lopez-Alegria and the keel pin, a few feet down the tracks. From the new location, Lopez-Alegria installs the keel pin in stowage brackets inside the P1 framework, completing the half-hour task.

2021 GMT (3:21 p.m. EST)

The spacewalkers are now putting thermal covers over the connectors and closing up the umbilical areas to complete this first job of today's EVA. NASA says the astronauts are running about 25 minutes ahead of the spacewalk timeline, plus the EVA started about 45 minutes early.

2014 GMT (3:14 p.m. EST)

John Herrington reports the second fluid jumper line has been connected. Leak checks can now begin.

2006 GMT (3:06 p.m. EST)

Mission Control reports a good leak check on cooling system valves following the connection of the fluid line between the S0 and P1 trusses.

1955 GMT (2:55 p.m. EST)

The spacewalkers are now mating the first fluid jumper to the P1 truss, which has been stretched from the S0 central truss segment of the space station. The jumper will eventually flow ammonia for the station's cooling system.

1936 GMT (2:36 p.m. EST)

Now an hour into the EVA. The spacewalkers are starting the fluid jumper work.

1910 GMT (2:10 p.m. EST)

Here is a preview of the spacewalkers' initial activities today:

Once they are out of the airlock and setup is complete, Lopez-Alegria and Herrington move to a point at the junction of S0 and P1 for a two-hour installation of fluid jumpers to move ammonia between the two. The two release two jumpers on S0, then move to the jumper install position.

Lopez-Alegria will mate and install Spool Positioning Devices on two jumper connections on the S0 side, while Herrington performs a similar task on the P1 side. Each connection will involve a three-minute leak check. Lopez-Alegria and Herrington reinstall the thermal booties and together they close their respective ends of the P1 and S0 utility tray shrouds.

1836 GMT (1:36 p.m. EST)

The Thanksgiving Day spacewalk by Mike Lopez-Alegria and John Herrington officially began at 1:36 p.m. EST when the two Endeavour mission specialists switched their spacesuits from station-provided power to internal batteries.

The planned 6 1/2 hour spacewalk, which has started about 45 minutes early today, will see the routing of ammonia fluid lines to the new P1 truss, removal the two keel pins used to secure P1 in Endeavour's payload bay during launch, the installation of a second wireless antenna system on the truss to support spacewalkers' "helmetcams" and the relocation of the CETA rail cart from P1 to the S1 truss on the opposite side of the station.

Read our detailed preview of this spacewalk.

1832 GMT (1:32 p.m. EST)

With the airlock now at vacuum, the "go" has been given to open the outer hatch lead to space.

1820 GMT (1:20 p.m. EST)

Depressurization of the Quest airlock is well underway. Pressure is currently holding at 5 psi while the crew checks the suits and communications. The official start time of the EVA will be timed not when vacuum is reached but when the suits go to internal battery power.

1720 GMT (12:20 p.m. EST)

Spacewalk preparations are going very well in the Quest airlock today. Mission Control predicts the EVA could begin as much as an hour early.

1545 GMT (10:45 a.m. EST)

While Americans enjoy traditional turkey dinners and college football, the Endeavour astronauts will be gearing up for a planned six-and-a-half-hour spacewalk by Mike Lopez-Alegria and John Herrington to continue the outfitting and activation of the P1 solar array truss that was attached to the international space station Tuesday. If all goes well, the spacewalkers will float out of the Quest airlock module around 2:20 p.m. EST.

Read our detailed preview of this spacewalk.

0400 GMT (11:00 p.m. EST Wed.)

Endeavour and International Space Station crewmembers worked Wednesday to transfer equipment and supplies between their docked spacecraft. Expedition 5 crewmembers exchanged notes with their Expedition 6 successors and mission specialists Michael Lopez-Alegria and John Herrington prepared for a Thanksgiving Day spacewalk.

The transfer of items between the two spacecraft is going smoothly, as are the handover briefings for Expedition 6 Commander Ken Bowersox, Cosmonaut Nikolai Budarin and NASA ISS Science Officer Don Pettit. Expedition 5 Commander Valery Korzun, NASA Science Officer Peggy Whitson and Flight Engineer Sergei Treschev are familiarizing the new arrivals with station systems and procedure, and discussing the location of equipment and supplies on the ISS.

Wednesday afternoon, Whitson and Bowersox replaced two valves and cleared debris from vent lines of the Carbon Dioxide Removal Assembly (CDRA) in the station's U.S. Destiny laboratory. The job was completed about 9 p.m. EST. Later Mission Control radioed them that the valve replacement had been successful, but that there was a leak in one of the CDRA vacuum lines. Whitson and Bowersox began efforts to find and fix that leak late Wednesday. CDRA had not been working well for the past several weeks. A Russian system cleanses the station atmosphere of the carbon dioxide exhaled by the normal three-person crew, but CDRA is needed to handle the load of larger crews.

NBC's Jay Leno wished Endeavour Commander Jim Wetherbee a happy 50th birthday. The good wishes were videotaped during Leno's show and transmitted to Endeavour via Houston's Mission Control Center.

Wednesday afternoon Wetherbee, Endeavour Pilot Paul Lockhart, Lopez-Alegria and Herrington talked with reporters from KFOR-TV of Oklahoma City, Okla., the Chickasaw Times newspaper; and the Cadena Ser radio network of Spain. The radio network spoke with Lopez-Alegria in Spanish.

Endeavour performed the first of three scheduled reboosts of the station a little after 12 p.m., increasing the altitude of the orbiting laboratory by about 2.8 statute miles. That left the average altitude of the station and Endeavour at almost 244 statute miles. Subsequent reboosts are scheduled for Friday and Sunday.

Thursday's second of three STS-113 spacewalks will see Lopez-Alegria and Herrington make more electrical, data and fluid line connections for the new Port One (P1) truss segment, install a second wireless video antenna system and move a Crew Equipment Translation Aid railway handcar from the P1 to the S1 truss. P1 was installed just before the Tuesday spacewalk. Thursday's and Saturday's spacewalks each will last about 6 1Ž2 hours.

Thanksgiving travel is being taken to new heights by Endeavour and ISS crewmembers. They will log about 1.68 million miles during the four-day weekend, with no weather or traffic delays, no airport security problems and certainly no crowds. Their vehicles' mileage over just those four days is excellent -- almost unlimited. Lopez-Alegria and Herrington are scheduled to travel about 227,500 Thanksgiving weekend miles outside the ISS-Endeavour complex during their two spacewalks.

WEDNESDAY, NOVEMBER 27, 2002
0400 GMT (11:00 p.m. EST Tues.)

The busiest day of Endeavour's mission was successfully pulled off Tuesday. The $390 million Port 1 truss was added to the space station's backbone, clearing the way for two shuttle astronauts to embark on a 7-hour spacewalk wire up the new structure and perform other tasks. Read our full story.

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

One down, two to go. Mike Lopez-Alegria and John Herrington have successfully completed the first of three planned spacewalks of Endeavour's current mission to the International Space Station, wiring up the P1 truss that was installed today, releasing launch locks on the truss' rail car and mounting a video antenna to the Unity node.

The spacewalk ended at 9:35 p.m. EST.

0224 GMT (9:24 p.m. EST Tues.)

Both spacewalkers are now back in the airlock, preparing to close the outer hatch. The official end of the EVA will be timed when repressurization of the airlock begins.

0201 GMT (9:01 p.m. EST Tues.)

Connection of the umbilicals to the WETA antenna has been completed. It is all bolted into place. And so the spacewalkers will now clean up, put away their tools and return to the airlock to conclude this EVA.

0149 GMT (8:49 p.m. EST Tues.)

Passing the six-hour mark of the spacewalk.

0136 GMT (8:36 p.m. EST Tues.)

The antenna system has been soft-docked on the Unity node. The spacewalkers will now bolt it into place and attach some cabling.

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

The spacewalkers are now working together to put the WETA onto the stanchion. Once that is completed, they will crawl over to Unity to mount the antenna structure to the U.S. connecting node.

0043 GMT (7:43 p.m. EST Tues.)

Nearing the five-hour mark in the spacewalk. Here's a preview of the upcoming installation of the Wireless video system External Transceiver Assembly (WETA) to the space station's Unity node. The WETA will be used to receive video from spacewalkers' helmet-mounted cameras inside the station.

Lopez-Alegria moves to the P1's starboard keel pin, retrieves the WETA stanchion and takes it to the Joint Airlock. There he and Herrington will spend about 15 minutes attaching the WETA to the stanchion. Herrington retrieves the WETA from its temporary airlock stowage position. While Lopez-Alegria holds the WETA in place, Herrington uses a pistolgrip tool to secure a center jacking bolt and then two outer bolts.

Lopez-Alegria, with the WETA, and Herrington move to the installation location on the node. With help from Herrington, Lopez-Alegria secures it by driving a stanchion bolt. Subsequently he mates three stanchion power and data connectors to the node.

0031 GMT (7:31 p.m. EST Tues.)

Mike Lopez-Alegria is finishing up the task of routing cabling from the top side of S0 to the new P1 truss. The next major activity of this spacewalk will be in the installation of an antenna package to the Unity node of the station.

0009 GMT (7:09 p.m. EST Tues.)

Rookie astronaut John Herrington, on his first spacewalk, has completed his planned activities to release multiple launch locks that held the CETA hand cart to the rail tracks on P1 during launch. The cart -- and one just like it on the S1 truss -- are designed to help spacewalkers move equipment up and down the station's railroad on the truss backbone.

Lopez-Alegria is busy hooking up the utility umbilicals on the top of P1 from the S0 truss.

This has really been a smooth, uneventful EVA today.

TUESDAY, NOVEMBER 26, 2002
2349 GMT (6:49 p.m. EST)

The EVA is passing the four-hour mark. The astronauts remain on the timeline.

2340 GMT (6:40 p.m. EST)

The spacewalkers are wrapping up the relocating activities with both drag links. Next, Lopez-Alegria will head to the top side of P1 to connect the second set of power, data and fluid umbilicals between the station's S0 and the new truss. Herrington will return to some more chores on CETA, including efforts to fix a troublesome pin that he uncovered a little while ago.

2315 GMT (6:15 p.m. EST)

The spacewalkers are now working together to remove the first drag link bar, which supports the keel pin that held P1 in Endeavour's payload bay. The bar is being unbolted and will be stowed in the P1 frame work.

2304 GMT (6:04 p.m. EST)

Now half-way through the intended 6 1/2 hour excursion, the 47th of space station construction work dating back to December 1998. The spacewalkers are about to move on to the relocation work for the P1 truss drag links.

2215 GMT (5:15 p.m. EST)

The spacewalkers remain right on the time, smoothly completing their respective jobs. They will be joining forces shortly to remove and stow the drag links on P1 -- part of the support equipment that held the truss in Endeavour's payload bay for launch.

2149 GMT (4:49 p.m. EST)

Today's spacewalk is passing the two-hour point. So far so good. No significant problems have been reported by Lopez-Alegria or Herrington. They both continue working their their "to do lists". Herrington is still working on the CETA locks and Lopez-Alegria is installing the Spool Positioning Devices.

2116 GMT (4:16 p.m. EST)

Lopez-Alegria has finished mating the first batch of utility umbilicals from the central section of the space station truss backbone to the new P1. He is now covering the cable tray on the bottom of P1 with a thermal shield. He will connect more umbilicals on the top of P1 later today.

While Herrington continues his extensive work on the CETA locks, Lopez-Alegria will turn his attention to the installation of clamp-like Spool Positioning Devices (SPDs) on Flex Hose Rotary Coupler (FHRC) Quick Disconnects (QDs) on lines running from the P1 truss to its still-folded radiator panels. The SPDs are designed to fix a flaw in the ammonia cooling lines of the station by keeping pressure from building up in the Quick Disconnects, which could make future spacewalkers' ability to unhook fittings highly difficult.

2049 GMT (3:49 p.m. EST)

Now one hour into today's spacewalk. Lopez-Alegria has started his scheduled 45-minute job of routing about seven cables to P1. The work involves demating the connectors from temporary attachment points on the S0 truss and mating the ends to receptacles on P1.

Herrington's 2 1/2-hour job is releasing bolts on the CETA cart launch locks.

2010 GMT (3:10 p.m. EST)

After some initial setup work, the spacewalkers will go their separate ways. Lopez-Alegria will be focused on connecting fluid, power and data umbilical lines from the station to the Port 1 truss. Herrington's job will be releasing the various launch locks and retraints on the Crew and Equipment Translation Aid (CETA) rail cart on the front side of P1.

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

Mike Lopez-Alegria, making the third spacewalk of his career, is outside the Quest airlock configuring tools and tethers. He is the spacewalker with red stripes on his suit.

John Herrington, an EVA rookie, will be floating out shortly. He has no stripes.

1949 GMT (2:49 p.m. EST)

The first of three spacewalks of Endeavour's mission by Mike Lopez-Alegria and John Herrington began at 2:49 p.m. EST as the two men switched their suits to internal battery power. This 6 1/2-hour excursion will route power and other umbilicals from the station to the newly installed P1 truss, release launch locks on the CETA equipment cart on the truss' railtracks and perform a few other chores.

1947 GMT (2:47 p.m. EST)

The outer hatch of the Quest airlock is now open.

1945 GMT (2:45 p.m. EST)

Depressurization is nearing completion. Once the airlock is at vacuum, the spacewalkers will open the outer hatch and switch their suits to internal battery power, which will mark the start of the EVA.

1928 GMT (2:28 p.m. EST)

The four and final bolt is now engaging between P1 and the station's central truss. Today's installation of P1 has gone extremely smoothly.

1915 GMT (2:15 p.m. EST)

The depressurization of the airlock has begun in advance of today's spacewalk. Pressure will be dropped to 5 psi for checks before going to vacuum.

1908 GMT (2:08 p.m. EST)

Three of the four motorized bolts have now successfully driven to securely mate P1 to S0, Mission Control reports.

From the NASA press kit, here is an overview of the P1 truss:

The Port One (P1) Truss is slated for launch to the International Space Station aboard space shuttle Endeavour...The truss is the next major addition to the space station's 11-segment Integrated Truss Structure that will eventually span more than 300 feet to carry power, data and temperature control for the orbital outpost's electronics. When completed, the ends of the truss structure will also house the station's solar arrays.

During Endeavour's mission, spacewalkers assisted by the ISS robotic arm, will attach P1 to the Starboard Zero (S0) Truss already in place aboard the U.S. laboratory module Destiny. Astronauts will make three spacewalks to complete installation and assembly of the P1. Space shuttle Atlantis delivered S1 to the ISS in October 2002 and it is attached to the other side of the S0 Truss.

The 27,506 lb. P1 Truss is primarily an aluminum structure that is 45 feet long, 13 feet high and 15 feet wide. The structure, along with one CETA (Crew and Equipment Translation Aid) cart, costs about $390 million.

Boeing designed the P1 Truss in Huntington Beach, Calif., and began construction there in January 1997. Work on P1 was completed in Huntsville, Ala., in June 2000. The P1 moved to Kennedy Space Center, Fla., in July 2000 for flight processing. Boeing delivered the P1 to NASA in November 2001 for final preparations and preflight checks.

Both P1 and S1 trusses will provide structural support for the Active Thermal Control System (ATCS), the Mobile Transporter, a CETA cart and antennas. The S1 has an S-band system; the P1 a UHF system. Both trusses also have mounts for cameras and lights. P1 also has a port for an S-band antenna. The S-band system is located on the P6 Truss and will be installed by spacewalkers on an upcoming mission.

Additionally, both S1 and P1 carry three radiators each containing eight panels as part of the ATCS or cooling system for the space station's electronics. The radiators are deployed in orbit and use 99.9 percent pure ammonia as compared to 1 percent strength found in the household variety. Ammonia rather than water is used because of its low freezing point and ability to transfer heat.

The radiator assembly also rotates to keep itself in the shade and away from the sun. Each radiator has 18 launch locks securing the assembly during launch which will be deployed/stowed during a spacewalk. The Thermal Radiator Rotary Joint (TRRJ) rotates the three radiator structures in a 105-degree span either way. The TRRJ also transfers power and ammonia to the radiators.

The addition of P1 also extends the Mobile Transporter (MT) rail line. The MT car travels along the length of the truss structure and carries spacewalkers, tools, construction items and the space station robotic arm. Flying aboard P1 is one of two CETA carts that move spacewalkers along the MT rails to worksites along the truss structure. The cart is manually operated by a spacewalker and can also be used as a work platform. S1 and P1 carry one cart each.

1848 GMT (1:48 p.m. EST)

The second-stage capture of P1 to the station has been completed, marking the official time of installation for the new 45-foot long truss structure. With the addition of the 14.5-ton P1, the station's mass grows to over 392,000 pounds.

1845 GMT (1:45 p.m. EST)

The capture claw on the central S0 truss segment of the space station continues to close around the capture bar of the P1 truss. Final bolting will follow.

Meanwhile, Endeavour pilot Paul Lockhart reports less than 18 minutes are left in the pre-breath for the spacewalkers. Depressurization of the airlock will follow. The EVA is expected to begin around 3 p.m. EST.

1836 GMT (1:36 p.m. EST)

A good first stage capture of P1 to station.

1821 GMT (1:21 p.m. EST)

Three ready-to-latch indications have been received. So the crew will start to drive the first of four motorized bolts and the first-stage capture of P1 to the station.

1815 GMT (1:15 p.m. EST)

Happy with the alignment, the astronauts are now moving the P1 truss to the ready-to-latch position.

1755 GMT (12:55 p.m. EST)

Now in the pre-install position, the fine alignment checks are underway to ensure the capture bar on the P1 truss is lined up correctly with the capture claw on the station's existing S0 truss.

Mission Control reports prep work in the Quest airlock for today's spacewalk is running about 35 minutes ahead of schedule.

Read our detailed preview of today's events.

1742 GMT (12:42 p.m. EST)

After checking the alignment, the robot arm is now moving the P1 truss into the pre-install position.

1726 GMT (12:26 p.m. EST)

The P1 truss is slowly inching closer to the International Space Station, riding on the end of the station's robot arm that is being controlled by Expedition 5 astronaut Peggy Whitson.

1706 GMT (12:06 p.m. EST)

Mike Lopez-Alegria and John Herrington continue preparations for today's spacewalk. Meanwhile, the robotics operations are running about 40 minutes ahead of schedule.

1650 GMT (11:50 a.m. EST)

Endeavour's Canadarm has let go of the P1 truss, leaving the 14.5-ton, 45-foot long girder in the hand of the station's Canadarm2 for today's installation to the outpost's existing S0 truss segment.

1641 GMT (11:41 a.m. EST)

The station's Canadian-made robot arm has grappled the P1 truss, which is currently being held off the port side of the shuttle by Endeavour's robot arm. This hand off from one arm to the other is necessary because Endeavour's arm can't physically reach the truss' installation point while the station arm couldn't reach P1 when it was still in the payload bay.

1555 GMT (10:55 a.m. EST)

The Endeavour astronauts and their space station counterparts are gearing up for the most critical day of the 112th shuttle mission: Installation of a new $390 million solar array truss segment, the third of 11 sections needed to complete the huge beam. Running well ahead of schedule, shuttle commander James Wetherbee, operating Endeavour's robot arm, began pulling P1 from its perch in the ship's cargo bay around 10:22 a.m. Read our detailed preview of today's events.

1506 GMT (10:06 a.m. EST)

The busiest day of Endeavour's mission has begun. Operating the shuttle's robotic arm, commander Jim Wetherbee has grappled the Port 1 truss in Endeavour's payload bay. This morning, the arm will gently lift the 14.5-ton truss structure from the bay and maneuver it into position for the station's arm to grab it. The station arm will then install the truss to the rest of the complex's growing backbone around 2 p.m. EST.

Meanwhile, shuttle astronauts Mike Lopez-Alegria and John Herrington are preparing to venture outside for a 6 1/2 hour spacewalk to connect cabling between the station and Port 1 truss. The EVA is due to start around 3:20 p.m. EST, after the truss is firmly mounted in place.

0340 GMT (10:40 p.m. EST Mon.)

Expedition 6 commander Kenneth Bowersox, flight engineer Nikolai Budarin and science officer Donald Pettit officially replaced the international space station's fifth full-time crew Monday night after installing and testing custom-fitted emergency gear. Read our full story.

MONDAY, NOVEMBER 25, 2002

Taking his time, commander James Wetherbee deftly guided the shuttle Endeavour to a gentle docking with the international space station today as the two spacecraft sailed 245 miles above the Pacific Ocean southeast of Australia. Read our full story.

2333 GMT (6:33 p.m. EST)

The hatchway between the space shuttle Endeavour and the space station is open. All 10 crew members are now together and beginning their busy timeline of joint work. After an initial welcoming ceremony, station commander Valery Korzun will give a safety briefing.

2214 GMT (5:14 p.m. EST)

The docking ring has been fully retracted and the hooks and latches have engaged to tightly seal the shuttle to the space station. Before the hatch opening can occur in about two hours, the astronauts have to complete a series of leak and pressure checks.

2159 GMT (4:59 p.m. EST)

CONTACT AND CAPTURE! Space shuttle Endeavour has docked to the International Space Station to deliver the sixth Expedition resident crew, install the Port 1 truss and pick up the Expedition 5 crew for their return to Earth. Docking occurred about a half-hour late at 4:59 p.m. EST over the South Pacific.

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 Endeavour'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. The work to exchange the Expedition crews will begin later today.

2156 GMT (4:56 p.m. EST)

Inside 15 feet, approaching at less than one-tenth of a foot per second.

2155 GMT (4:55 p.m. EST)

The orientation-control gyros on the station are disabled for the docking to keep the complex from moving, while some of Endeavour's thrusters are programmed to fire in a post-contact maneuver to force the two docking ports together.

2153 GMT (4:53 p.m. EST)

Distance now 28 feet.

2151 GMT (4:51 p.m. EST)

The alignment between docking ports on Endeavour and the space station is acceptable and no "fly out" maneuver by the shuttle is necessary. The shuttle and station are fly 247 miles over northern Australia.

2150 GMT (4:50 p.m. EST)

Inside 43 feet.

2148 GMT (4:48 p.m. EST)

Fifty feet to go.

2146 GMT (4:46 p.m. EST)

Now 58 feet separating Endeavour and station.

2142 GMT (4:42 p.m. EST)

Less than 80 feet from docking.

2141 GMT (4:41 p.m. EST)

The two spacecraft are now passing into orbital daylight.

2139 GMT (4:39 p.m. EST)

Endeavour is now inside the final 100 feet to docking, continuing the very slow approach. Mission Control reiterates that this later-than-planned docking won't impact the rest of today's activities, which include the handover between Expedition 5 and 6 crews.

2135 GMT (4:35 p.m. EST)

Distance now 120 feet.

2130 GMT (4:30 p.m. EST)

Distance now 150 feet.

2126 GMT (4:26 p.m. EST)

Commander Jim Wetherbee continues to guide Endeavour right down the corridor for today's link up with the station. Although running about 20-25 minutes late, no problems have been reported in the rendezvous.

2122 GMT (4:22 p.m. EST)

Now 200 feet from docking. Endeavour still closing at about one-tenth of a foot per second.

2116 GMT (4:16 p.m. EST)

The shuttle is approaching to the station's front docking port along the velocity vector, or V-bar. Distance now 250 feet.

2108 GMT (4:08 p.m. EST)

Astronaut Mike Lopez-Alegria has powered up the Orbiter Docking System in Endeavour's payload bay. The shuttle is currently 320 feet from the docking port, closing at one-tenth of a foot per second. It does appear docking will occur a little late today. But that is not a problem.

2101 GMT (4:01 p.m. EST)

Endeavour is now 390 feet out in front of the station.

2054 GMT (3:54 p.m. EST)

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

2044 GMT (3:44 p.m. EST)

Endeavour is reaching the milestone point directly feet below the space station. Commander Jim Wetherbee is taking over manual control for the remainder of today's rendezvous and docking of Endeavour to the international space station.

Piloting the shuttle from the aft control station on the flight deck of Endeavour, he will regularly pulse the shuttle's steering jets to keep the shuttle on the correct course.

The shuttle will make an arc from the point below to a point in front of the space station before beginning the final approach. Docking at the front of the station -- to the Destiny module -- is scheduled for 4:26 p.m. EST.

2039 GMT (3:39 p.m. EST)

Endeavour is currently 800 feet beneath the space station. Mission Control reports the Russian solar arrays have been feathered for docking.

2031 GMT (3:31 p.m. EST)

The station is reported in docking attitude. The U.S. solar arrays on the P6 truss have been "feathered" in preparation for docking. And so station flight director Andy Algate has given his "go" for Endeavour's continued approach for today's link up.

2026 GMT (3:26 p.m. EST)

An hour is left until the planned docking time. However, there isn't a specific window in which docking must occur, so if the approach takes a bit longer than expected it won't be a problem.

2017 GMT (3:17 p.m. EST)

Now 5,000 feet separating the two craft.

2007 GMT (3:07 p.m. EST)

Endeavour is about two miles from the space station. The shuttle remains on track for docking at 4:26 p.m. EST.

A pair of small course correction maneuvers have been performed by Endeavour, refining the shuttle's path to the station. Also, the approximate half-hour process to maneuver the station into the proper docking attitude has begun. And the station's solar arrays are being "feathered" so they are edge-on to the approaching shuttle.

The shuttle is headed to a point 600 feet directly below the station. From there, commander Jim Wetherbee will take manual control of Endeavour to fly the orbiter a quarter-loop to a spot 310 feet directly in front of the station. The slow final approach then starts as the shuttle inches closer for the precision docking.

1906 GMT (2:06 p.m. EST)

With about eight statute miles separating Endeavour and the space station, the shuttle has fired its left orbital maneuvering system engine for the Terminal Initiation burn. A camera on the station saw a noticeable puff as the firing occurred.

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 Endeavour's final approach to the station after nearly two days of chasing the complex since launch. Docking is set for 4:26 p.m. EST.

1550 GMT (10:50 a.m. EST)

The Endeavour astronauts have kicked off a busy day of work to rendezvous and dock with the international space station. Endeavour's launching Saturday night was timed to set up a docking with the station today at 4:26 p.m. EST (2126 GMT) as the two spacecraft sail 250 miles above eastern Asia. Read our full story.

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

Endeavour's crew spent its first full day in space preparing for its arrival at the International Space Station. Endeavour, now 1,400 miles behind the station and closing, is scheduled to dock at 4:26 p.m. EST Monday.

In preparation for Monday's docking, Endeavour's crew - Commander Jim Wetherbee, Pilot Paul Lockhart, Mission Specialists Mike Lopez-Alegria and John Herrington, and the Expedition Six crew Commander Ken Bowersox, NASA ISS Science Officer Don Pettit and flight engineer Nikolai Budarin - verified operation of the equipment used to support a smooth rendezvous and soft docking. A camera was installed to give Wetherbee a view of the station's docking port through the shuttle's docking system, a shock-absorbing ring that will make the first contact was extended and a variety of handheld cameras and distance-measuring devices were checked out. In addition, Lopez-Alegria and Herrington inspected and checked out the spacesuits being delivered to the station for use on three spacewalks to install and outfit the P1 truss segment.

Checkout of the shuttle's Remote Manipulator System went smoothly Sunday, but the robotic arm camera survey of Endeavour's payload bay ran a little longer than expected. The robotic arm's wrist roll joint was commanded in extra maneuvers to help work in lubrication that was applied during the arm's preflight servicing. The robotic arm is ready to support operations to remove Endeavour's primary cargo, the P1 or port truss, from the payload bay on Tuesday.

Also Sunday, Bowersox, Budarin and Pettit spoke with reporters from USA Today and AP Radio News. The trio will become the sixth resident crew to live and work in space aboard the International Space Station, replacing the current Expedition Five residents.

Onboard the station, the Expedition Five crew, Commander Valery Korzun, NASA ISS Science Officer Peggy Whitson and Flight Engineer Sergei Treschev, continued preparations for the arrival of Endeavour, and their replacement crew.

Endeavour's crew is scheduled to go to sleep about 12:20 a.m. EST time awaken about 8:20 a.m. Monday.

SUNDAY, NOVEMBER 24, 2002

Lighting up the night sky with white-hot fire, the shuttle Endeavour finally thundered into orbit and set off after the international space station Saturday night, carrying a 14.5-ton solar array truss segment and a fresh three-man crew to the orbiting lab complex. Read our complete launch wrap-up and mission preview story.

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

Go for orbit ops! Mission Control has given the crew of Endeavour continued orbital flight.

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

The payload bay doors of space shuttle Endeavour have been opened by mission specialists Mike Lopez-Alegria and John Herrington.

0221 GMT (9:21 p.m. EST Sat.)

With shuttle's radiators now activated on the inside of the payload bay doors, the "go" has been given for door opening.

0205 GMT (9:05 p.m. EST Sat.)

Endeavour is now maneuvering into the proper orientation for opening of the payload bay doors, expected in about 15 minutes.

0140 GMT (8:40 p.m. EST Sat.)

Today's official launch time was 7:49:47.079 p.m. EST.

0133 GMT (8:33 p.m. EST Sat.)

T+plus 43 minutes, 45 seconds. The left Orbital Maneuvering System engine on the tail of Endeavour have been fired successfully to propel the shuttle the rest of the way to orbit.

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

T+plus 42 minutes. The OMS burn continues with no issues reported by Mission Control.

0127 GMT (8:27 p.m. EST Sat.)

T+plus 38 minutes. The five-minute firing of the left Orbital Maneuvering System engine has begun to place Endeavour into a stable orbit. The right engine is not being used because of a stuck ball valve that was found during the OMS assist burn during ascent.

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

T+plus 26 minutes. Just under 12 minutes away from the OMS 2 burn. It will be an approximate five-minute firing of the left OMS engine on the tail of Endeavour.

The two flapper doors on the belly of Endeavour are being swung closed to shield the umbilicals that had connected to the external fuel tank. And the main propulsion system inerting has been performed.

0109 GMT (8:09 p.m. EST Sat.)

T+plus 20 minutes. Mission Control reports that ball valve in the right Orbital Maneuvering System engine was stuck open at about 96 percent of its operational positioning during launch. NASA spokesman Rob Navias says that is not a mission impact.

However, the upcoming OMS 2 burn at T+plus 37 minutes, 49 seconds to propel Endeavour from its suborbital trajectory into a stable orbit will use only the left OMS engine. The shuttle's current orbit is 144 by 36.5 statute miles.

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

T+plus 14 minutes, 40 seconds. The Expedition 5 crew aboard the space station has been given the news that Endeavour is en route. They will ride back to Earth on the shuttle after being replaced by Expedition 6.

Meanwhile, Endeavour's three APU hydraulic-powering units have been shut down. They won't be needed until an entry system checkout on the day before landing, and then again for Endeavour's high-speed return to Earth and touchdown.

0058 GMT (7:58 p.m. EST Sat.)

T+plus 8 minutes, 55 seconds. The emptied external tank has been jettisoned from the belly of space shuttle Endeavour. The tank will fall back into the atmosphere where it will burn up harmlessly.

0058 GMT (7:58 p.m. EST Sat.)

T+plus 8 minutes, 30 seconds. MECO! Confirmation that Endeavour's main engines have cutoff as planned, completing the powered phase of the launch. Space shuttle Endeavour has safely embarked on its two-day chase to rendezvous and dock with the space station on Monday.

0057 GMT (7:57 p.m. EST Sat.)

T+plus 7 minutes, 45 seconds. The main engines beginning to throttle back to ease the force of gravity on the shuttle and astronauts.

0057 GMT (7:57 p.m. EST Sat.)

T+plus 7 minutes, 30 seconds. The shuttle remains right on course. Downrange distance 600 miles.

0056 GMT (7:56 p.m. EST Sat.)

T+plus 6 minutes, 15 seconds. Endeavour is rolling to a heads-up position.

0055 GMT (7:55 p.m. EST Sat.)

T+plus 5 minutes, 25 seconds. Endeavour is 273 miles northeast of the launch pad at an altitude of 67 miles. Endeavour can now reach a orbit on the power of two main engines should one fail. But all three continue to fire properly.

0054 GMT (7:54 p.m. EST Sat.)

T+plus 4 minutes, 30 seconds. Three good main engines, three good APUs, three good fuel cells.

0053 GMT (7:53 p.m. EST Sat.)

T+plus 4 minutes, 15 seconds. Altitude 62 miles, downrange distance 163 miles.

0053 GMT (7:53 p.m. EST Sat.)

T+plus 4 minutes. 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.

0052 GMT (7:52 p.m. EST Sat.)

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

0051 GMT (7:51 p.m. EST Sat.)

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

0051 GMT (7:51 p.m. EST Sat.)

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

0050 GMT (7:50 p.m. EST Sat.)

T+plus 60 seconds. Endeavour's engines have throttled back up.

0050 GMT (7:50 p.m. EST Sat.)

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

0050 GMT (7:50 p.m. EST Sat.)

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 cruising 240 miles above above Austria.

0049:47 GMT (7:49:47 p.m. EST Sat.)

LIFTOFF! Liftoff of space shuttle Endeavour -- continuing construction of the International Space Station while exchanging its resident crews. And the shuttle has cleared the tower!

0049:16 GMT (7:49:16 p.m. EST Sat.)

T-minus 31 seconds. Auto sequence start. Endeavour'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.

0048:47 GMT (7:48:47 p.m. EST Sat.)

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; Endeavour 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.

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

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.

0047:17 GMT (7:47:17 p.m. EST Sat.)

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

Endeavour'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 Paul Lockhart has been asked to clear the caution and warning memory system aboard Endeavour.

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.

0046:47 GMT (7:46:47 p.m. EST Sat.)

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

0046:17 GMT (7:46:17 p.m. EST Sat.)

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.

0045:47 GMT (7:45:47 p.m. EST Sat.)

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 Endeavour 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.

0045 GMT (7:45 p.m. EST Sat.)

T-minus 5 minutes. The "go" has been given for for Auxiliary Power Unit start. Pilot Paul Lockhart is now flipping three switches in Endeavour's cockpit to start each of the three APU's. The units, located in the aft compartment of Endeavour, 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 Jim Wetherbee, 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.

0044 GMT (7:44 p.m. EST Sat.)

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.

0043 GMT (7:43 p.m. EST Sat.)

T-minus 6 minutes. Pilot Paul Lockhart has been asked by Orbiter Test Conductor Jeff Lauffer 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.

0042:17 GMT (7:42:17 p.m. EST Sat.)

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 Endeavour 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.

0041:47 GMT (7:41:47 p.m. EST Sat.)

T-minus 8 minutes and counting. Pilot Paul Lockhart has flipped the switches in the cockpit of Endeavour 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.

0040:47 GMT (7:40:47 p.m. EST Sat.)

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 Endeavour at 7:49:47 p.m. EST. The GLS will monitor as many as a thousand different measurements to ensure they do not fall out of predetermine red-line limits.

0039:47 GMT (7:39:47 p.m. EST Sat.)

Two minutes remaining in this built-in hold.

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

0037 GMT (7:37 p.m. EST Sat.)

NASA Launch Director Mike Leinbach has polled senior officials and no technical problems were announced. The launch weather conditions were also verified "go" for liftoff with no constraints.

0036 GMT (7:36 p.m. EST Sat.)

The final readiness poll by NASA Test Director Steve Altemus 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. And Ascent Flight Director Wayne Hale gave his "go", which also confirms that the TAL weather at Zaragoza will be acceptable tonight.

0030:47 GMT (7:30:47 p.m. EST Sat.)

There are 10 minutes remaining in this planned hold at the T-minus 9 minute mark.

0023 GMT (7:23 p.m. EST Sat.)

The payload team has been polled with everyone reporting "go" for launch. The Port 1 truss and middeck experiments are ready to fly.

0020 GMT (7:20 p.m. EST Sat.)

Now 30 minutes away from launch time. No issues, technical or weather, are being worked at this point.

Two solid rocket booster recovery ships -- the Freedom Star and Liberty Star -- are reported 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 yesterday 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 weekend, arriving on Monday afternoon.

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

So with Zaragoza weather likely to cooperate tonight, there are now no issues being worked. Liftoff set for 7:50 p.m. EST.

0007 GMT (7:07 p.m. EST Sat.)

Meteorologists in Mission Control has become quite optimistic about the weather at Zaragoza and plans to remove the chance of showers from the forecast, which paves the way to launching tonight!

2355 GMT (6:55 p.m. EST)

T-minus 9 minutes and holding. Countdown clocks have gone into the planned 45-minute, 47-second built-in hold. Today's launch remains set for 7:49:47 p.m. EST, weather permitting.

2351 GMT (6:51 p.m. EST)

The Main Propulsion System helium system is being reconfigured by pilot Lockhart. The OMS cross feed valves have been configured. And the gaseous nitrogen purge to the aft skirts of the solid rocket boosters will be started.

2349 GMT (6:49 p.m. EST)

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

2344 GMT (6:44 p.m. EST)

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 7:49:47 p.m. EST.

Endeavour'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.

In about one minute, the astronauts will configure the backup computer to MM-101 and the test team will verify backup flight control system (BFS) computer is tracking the PASS computer systems.

2334 GMT (6:34 p.m. EST)

T-minus 20 minutes and holding. The countdown has paused for a 10-minute built-in hold. Launch remains scheduled for 7:49:47 p.m. EST.

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

2324 GMT (6:24 p.m. EST)

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 Endeavour'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.

Commander Jim Wetherbee has pressurized the gaseous nitrogen system for Endeavour's Orbital Maneuvering System engines, and pilot Paul Lockhart has activated the gaseous nitrogen supply for the orbiter's Auxiliary Power Units' water boilers.

2318 GMT (6:18 p.m. EST)

The latest weather briefing to managers indicates that both Zaragoza and Moron are observed "go" at the moment. That is not expected to last at Moron, however. But there remains some hope that a drying pattern will be affecting Zaragoza this evening, allowing forecasters to remove the chance of showers from the forecast.

The ground pyro initiator controllers (PICs) are scheduled to be powered up at 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.

Endeavour'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.

2310 GMT (6:10 p.m. EST)

The Orbiter Closeout Crew reports hatch closure activities are now complete. And breakdown of the White Room is starting.

And the Ground Launch Sequencer mainline activation has been completed.

2254 GMT (5:54 p.m. EST)

Now inside two hours from tonight's planned 7:49:47 p.m. EST launch. The main concern continues to be weather at the TAL abort landing sites in Spain. But there remains hope that conditions might be acceptable at Zaragoza.

The pre-flight alignment of Endeavour's Inertial Measurement Units is now beginning, 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 are shifting from low power to high power. The site will provide voice, data and telemetry relay between Endeavour and Mission Control during the first few minutes of flight. Coverage then is handed to a NASA Tracking and Data Relay Satellite in space.

2237 GMT (5:37 p.m. EST)

The ice team is giving its briefing to the launch management. Some frost is being observed on the tank, which is does happen from time to time and of no concern.

2235 GMT (5:35 p.m. EST)

Endeavour's crew module hatch is now swinging 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.

2231 GMT (5:31 p.m. EST)

And the Orbiter Closeout Crew has removed the non-flight items and equipment from Endeavour. And the "go" has been given to close the hatch for flight.

2224 GMT (5:24 p.m. EST)

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 7:49:47 p.m. EST. There are no technical issues being address. Only weather in Spain is a concern tonight.

With all seven astronauts strapped inside Endeavour's crew module, preparations are now beginning 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 flight.

2206 GMT (5:06 p.m. EST)

The last of the astronauts to board Endeavour today -- mission specialist number 2 and flight engineer John Herrington -- has climbed through the shuttle's hatch. He will sit in the aft-center seat on the flight deck. Read Herrington's bio here.

Meanwhile, a purge of Endeavour's fuel cells has been performed.

2157 GMT (4:57 p.m. EST)

Expedition 6 science officer Don Pettit, the mission specialist number 5 for launch, has boarded the shuttle and taken his center seat on the mid deck. Pettit replaced Don Thomas on the crew due to a medical issue. Read Pettit's bio here.

2151 GMT (4:51 p.m. EST)

Endeavour mission specialist number 1 Mike Lopez-Alegria has just climbed through the hatch. He will be seated on the flight deck aft right seat. Read Lopez-Alegria's bio here.

2140 GMT (4:40 p.m. EST)

Expedition 6 commander Ken Bowersox, the mission specialist number 3 for launch, has boarded the shuttle and taken his left seat on the mid deck. Read Bowersox's bio here.

2133 GMT (4:33 p.m. EST)

Pilot Paul Lockhart is now aboard and has taking his front right seat on the flight deck. This is Lockhart's second shuttle mission of the year. He stepped in to replace Gus Loria on this mission. NASA says Loria was removed from the flight after he injured his back at home. Read Lockhart's bio here.

2131 GMT (4:31 p.m. EST)

Commander Jim Wetherbee, a veteran of five previous shuttle missions, was the first to climb aboard Endeavour. He has taken his front-left seat on the flight deck. Read Wetherbee's bio here.

Next came mission specialist number 4 and Expedition 6 flight engineer Nikolai Budarin. His position is the right seat on the mid deck. Read Budarin's bio here.

2122 GMT (4:22 p.m. EST)

The astronauts have arrived at launch pad 39A.

The crew will take the elevator to the 195-foot level of the pad structure where the Orbiter Access Arm is located with the White Room. In the White Room the crew will be outfitted with the rest of their gear and communications hat before entering Endeavour's crew module hatch.

2110 GMT (4:10 p.m. EST)

The "AstroVan" with the astronauts aboard just drove past the Kennedy Space Center Press Site en route to launch pad 39A.

The crew departed their quarters at the Operations & Checkout Building in Kennedy Space Center's Industrial Area bound around a little while ago and boarded the "AstroVan" for the 20-minute ride to the pad located on the edge of the Atlantic Ocean, about 10 miles away.

2054 GMT (3:54 p.m. EST)

T-minus 3 hours and counting. The countdown has resumed on scheduled from this planned two-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. Liftoff remains set for 7:49:47 p.m. EST.

At the time of launch, the orbiting International Space Station will be flying over Europe. Docking of Endeavour to the station is expected around 4:26 p.m. EST Monday, given an on-time launch tonight.

2023 GMT (3:23 p.m. EST)

The astronauts are currently receiving a weather briefing by the Spaceflight Meteorology Group at Mission Control. The latest forecast is still calling for a chance of showers within 20 miles at Zaragoza and a cloud ceiling at 2,500 feet and showers within 20 miles at Moron. One of the two sites must have acceptable weather for Endeavour to be permitted to launch.

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

Apparently there was some confusion from the NASA spokespeople. The beanie cap issue is a hydraulic leak, not an oxygen leak. In any event, the "red crew" sent to the pad is working the situation and this isn't expected to be any concern for launch. The TAL weather is the key tonight. A weather briefing to the astronauts is coming up shortly.

1920 GMT (2:20 p.m. EST)

Now entering the final five-and-a-half hours to the launch of Endeavour.

After last night's scrub, technicians de-tanked the propellants from Endeavour as part of standard turnaround activities. De-tanking began at about 8:45 p.m. and concluded at 11:30 p.m. EST. Endeavour's external tank was re-fueled today and now stands fully loaded with liquid hydrogen and liquid oxygen. Filling of the tank officially began at 10:45 a.m. and was completed at 1:45 p.m. EST.

Following tanking procedures, a team called the Final Inspection Team was dispatched to the pad to check the vehicle one last time prior to liftoff. The team, comprised of engineers and a safety official, is currently performing the inspections at pad 39A. At the conclusion of their two-hour tour-of-duty, they 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 that could break-off during ignition and damage the spacecraft. The team is also searching for any loose debris that could possibly fly up and strike the vehicle at launch. And the third item of interest to the team is the thermal 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. One team member is also responsible for photo documentation.

Each member of the Final Inspection Team is in constant contact with NASA Test Director Steve Altemus in the Firing Room.

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.

Following the Final Inspection Team's activities, they will meet with NASA Launch Director Mike Leinbach, the Mission Management Team, and engineering directors in the launch control center, providing a detailed report on the inspections and findings at the pad 39A.

A full inspection of the vehicle and pad was performed yesterday and the external tank received a thorough check prior to fueling today.

An inspection of the launch pad and beach will be made following launch. That inspection will be to look for anything unusual, particularly anything that could have fallen off of the vehicle during the first few seconds of flight. Later, there will be a meeting to review high-speed videotape and film of the launch and early ascent to determine if there was any damage to the vehicle.

1900 GMT (2:00 p.m. EST)

Confirmation has been received that tanking was completed at 1:45 p.m. EST, right on time today. A small oxygen leak has been detected in the beanie cap, however. So a special "red crew" has been dispatched to the pad to investigate, a NASA spokesman says. The beanie cap is the gaseous oxygen vent hood that sits over the tip of the external tank until 2 1/2 minutes before launch when it is retracted. The hood vents away gaseous oxygen from the external tank and prevents ice from forming on the tank's nose, would could fall off and damage Endeavour during launch.

1854 GMT (1:54 p.m. EST)

T-minus 3 hours and holding. Countdown clocks have entered a planned two-hour built-in hold. We're awaiting word from NASA that fueling has been completed.

1745 GMT (12:45 p.m. EST)

Fueling continues at launch pad 39A with no problems reported on a beautifully clear November day here at the Cape.

1612 GMT (11:12 a.m. EST)

The launch team began pumping cryogenic propellants into space shuttle Endeavour's external tank at 10:45 a.m. EST, marking the start of the three-hour fueling process. This is the third time Endeavour has been fueled for this shuttle mission. Liftoff is scheduled for 7:50 p.m. EST.

To recap, mission managers met this morning and opted to move forward with tonight's launch attempt even though there are still weather concerns at the TAL abort landing sites in Spain, which scrubbed last night's try.

Low clouds and rain showers expected at the Moron Air Base in southern Spain and a chance for more showers in the vicinity of Zaragoza, 394 miles to the northeast.

NASA requires that one site have good weather to allow Endeavour to land in the case of a engine failure during launch. A shuttle has never made an emergency landing in the 21-year history of the program.

The local weather here in Florida is near-perfect with a 95 percent chance of acceptable launch weather conditions.

If Endeavour does not fly tonight, there are two options being discussed:

• Skip Sunday and top off the shuttle's hydrogen reactants in the fuel cells, which generate electricity and drinking water during the mission. That would allow for launch attempts on Monday and Tuesday. If Endeavour still hasn't launched by then, both hydrogen and oxygen reactants would need to be serviced, pushing the next opportunity to Friday.
• The other option would see a launch try on Sunday. If the launch didn't occur, hydrogen and oxygen reactant supplies would be replenished, making the next attempt around Thanksgiving.

The TAL weather improves as days go by but the Florida weather will worsen.

1532 GMT (10:32 a.m. EST)

NASA has made the decision, despite "no go" forecasts for both overseas abort landing sites in Spain, to fuel space shuttle Endeavour and make another launch attempt tonight. Liftoff is scheduled for 7:50 p.m. EST, the middle of a 10-minute launch window.

1515 GMT (10:15 a.m. EST)

This morning's forecast from SMG is calling for a chance of showers within 20 miles at Zaragoza and low clouds and showers within 20 at Moron. Again, one of those two sites in Spain must have acceptable weather to support an emergency landing by Endeavour should the shuttle have a major problem during ascent.

1500 GMT (10:00 a.m. EST)

Mission managers have convened their pre-tanking meeting to decide whether to press ahead with another launch attempt tonight.

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

And all seven crew members have now crawled out of Endeavour following tonight's scrub. We'll conclude our coverage for the night. The Mission Management Team meets at 9:45 a.m. EST to review the weather before deciding whether to begin fueling Endeavour for another launch attempt tomorrow.

0211 GMT (9:11 p.m. EST Fri.)

The Spaceflight Meteorology Group in Mission Control has just offered an updated briefing on the predicted conditions Saturday night in Spain. Moron is expected to have similar weather as was experienced tonight; Zaragoza could have some improvement.

Meanwhile, the weather here at Kennedy Space Center is expected to be near-ideal with a 95 percent chance of acceptable conditions.

0206 GMT (9:06 p.m. EST Fri.)

The astronauts are now making their way off Endeavour. They will head back to the crew quarters for dinner and then to bed for the night.

0155 GMT (8:55 p.m. EST Fri.)

Launch of the shuttle Endeavour was called off this evening because of hard-to-predict rain showers at an emergency runway near Moron, Spain. The launch team now is recycling for another launch attempt Saturday night at 7:49:47 p.m. EST, weather permitting. Again, the launch window will last just five minutes and again, the weather in Spain is expected to be marginal at best. Read our full story.

0111 GMT (8:11 p.m. EST Fri.)

Saturday's launch window extends from 7:44:48 to 7:54:46 p.m. EST. The preferred launch time will be 7:49:47 p.m. EST.

0107 GMT (8:07 p.m. EST Fri.)

SCRUB! Tonight's launch attempt has been scrubbed due to unstable weather conditions at the emergency landing sites in Spain. NASA requires that one of two locations -- Zaragoza or Moron -- must have acceptable weather to ensure Endeavour has a place to safely land in the event of a major problem during launch.

Another launch attempt is being planned for tomorrow night.

0106 GMT (8:06 p.m. EST Fri.)

The hold at T-minus 9 minutes has been extending. A scrub has not been called. In addition, the Range is reporting a computer problem.

0105 GMT (8:05 p.m. EST Fri.)

Ascent Flight Director Wayne Hale reports weather in Spain will not cooperate tonight.

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

Still reporting "no go" weather in Spain and very little hope remains.

0102 GMT (8:02 p.m. EST Fri.)

The final readiness poll by NASA Test Director Steve Altemus 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.

However, Mission Control gave a "no go" due to TAL weather.

0101 GMT (8:01 p.m. EST Fri.)

The forecasters in Houston report they don't feel like the chance of showers at Moron can be removed from the forecast tonight.

0100 GMT (8:00 p.m. EST Fri.)

Countdown activities are continuing to ensure the vehicle and ground systems are ready to support an on-time launch if the weather in Spain allows tonight.

0057 GMT (7:57 p.m. EST Fri.)

The weather watch continues. Moron is appearing the like best hope at this point. But there is a shower that could be the spoiler for launch tonight. Again, one TAL site must have acceptable weather before Endeavour launch.

0045 GMT (7:45 p.m. EST Fri.)

Now 30 minutes away from launch time.

Two solid rocket booster recovery ships -- the Freedom Star and Liberty Star -- are reported 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 yesterday 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 weekend.

0039 GMT (7:39 p.m. EST Fri.)

The payload team has been polled with everyone reporting "go" for launch.

0028 GMT (7:28 p.m. EST Fri.)

The Spaceflight Meteorology Group at Mission Control reports conditions at Moron is currently observed "go", but predicted to be marginally "no go" by launch time due to a chance of showers within 20 miles. For the past couple days, forecasters had expected Moron to be solidly "no go" tonight. Conditions have been improving tonight, however. At Zaragoza, which had been expected to be the best hope, remains iffy at best.

0023 GMT (7:23 p.m. EST Fri.)

For those keeping tracking at home, the pilots of the weather reconnaissance aircraft tonight are Ronald Garan at Zaragoza and Doug Hurley at Moron.

0021 GMT (7:21 p.m. EST Fri.)

T-minus 9 minutes and holding. Countdown clocks have gone into the planned 45-minute, 30-second built-in hold. Today's launch remains set for 8:15:30 p.m. EST. There are no significant technical problems being reported. Weather in Spain remains the main concern.

0017 GMT (7:17 p.m. EST Fri.)

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

0015 GMT (7:15 p.m. EST Fri.)

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

0010 GMT (7:10 p.m. EST Fri.)

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 8:15:30 p.m. EST.

Endeavour'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.

In about one minute, the astronauts will configure the backup computer to MM-101 and the test team will verify backup flight control system (BFS) computer is tracking the PASS computer systems.

0004 GMT (7:04 p.m. EST Fri.)

With their work all completed, the Orbiter Closeout Crew is now leaving the pad.

0000 GMT (7:00 p.m. EST Fri.)

T-minus 20 minutes and holding. The countdown has paused for a 10-minute built-in hold. Launch remains scheduled for 8:15:30 p.m. EST.

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

FRIDAY, NOVEMBER 22, 2002
2355 GMT (6:55 p.m. EST)

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 Endeavour'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.

Commander Jim Wetherbee has pressurized the gaseous nitrogen system for Endeavour's Orbital Maneuvering System engines, and pilot Paul Lockhart has activated the gaseous nitrogen supply for the orbiter's Auxiliary Power Units' water boilers.

2345 GMT (6:45 p.m. EST)

The ground pyro initiator controllers (PICs) are scheduled to be powered up at 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.

Endeavour'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.

A short time ago, the Ground Launch Sequencer mainline activation has been completed.

2339 GMT (6:39 p.m. EST)

Launch Director Mike Leinbach and Ascent Flight Director Wayne Hale have received another weather briefing. Conditions are just fine here in Florida at Kennedy Space Center. There is no change to the forecast at Zaragoza, with the concern of showers within 20 miles. A slight improvement at Moron might be occurring, but it is too soon to tell. The concern at Moron has been low clouds, rain and turbulence.

The bottom line, NASA commentator George Diller says, is there remains some hope and worth continuing the coutdown. There are no technical issues being worked.

2332 GMT (6:32 p.m. EST)

Mission Control has confirmed there is NO change to tonight's launch window of 8:10:31 to 8:20:30 p.m. EST. The preferred launch time is still 8:15:30 p.m. EST.

2320 GMT (6:20 p.m. EST)

The pre-flight alignment of Endeavour's Inertial Measurement Units is now beginning, 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 are shifting from low power to high power. The site will provide voice, data and telemetry relay between Endeavour and Mission Control during the first few minutes of flight. Coverage then is handed to a NASA Tracking and Data Relay Satellite in space.

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

Endeavour'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.

2310 GMT (6:10 p.m. EST)

The ice team has completed its briefing to the launch management with no problems of note.

2258 GMT (5:58 p.m. EST)

The red crew looking at the actuator issue with the Orbiter Access Arm has wrapped up its work and there is no contraint for launch. Meanwhile, the ice team has finished its inspections of the pad and shuttle. No concerns were reported.

And the Orbiter Closeout Crew reports all non-flight items have been removed from Endeavour in advance of closing the hatch for flight.

2250 GMT (5:50 p.m. EST)

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 8:15:30 p.m. EST.

With all seven astronauts strapped inside Endeavour's crew module, preparations are now beginning 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 flight.

2236 GMT (5:36 p.m. EST)

The last of the astronauts to board Endeavour today -- mission specialist No. 2 and flight engineer John Herrington -- has climbed through the shuttle's hatch. He will sit in the aft-center seat on the flight deck. Read Herrington's bio here.

It's an absolutely beautiful night here at Kennedy Space Center. A spectacular sunset on a clear evening. But the weather in Spain, at the two available TAL abort landing sites, remains a real concern. The rain is in bands and the hope is there will be a clearing around launch time at Zaragoza. Moron is solidly "no go" tonight.

An engine failure during the first two mintues and 26 seconds of flight would result in a return-to-launch-site abort and a landing back at the Kennedy Space Center. The trans-Atlantic abort option kicks in immediately thereafter and remains an option during most of the ascent. But for Endeavour's flight, the practical TAL window only extends to launch plus five minutes and four seconds. After that, the shuttle could make it into a lower-than-planned orbit on just two main engines. But an engine failure during that two-minute 38-second TAL window of vulnerability would leave Endeavour without enough fuel to make it back to Florida or enough to get into orbit. In that case, Spain would be the only viable option.

2227 GMT (5:27 p.m. EST)

Expedition 6 science officer Don Pettit, the mission specialist No. 5 for launch, has boarded the shuttle and taken his center seat on the mid deck. Pettit replaced Don Thomas on the crew due to a medical issue. Read Pettit's bio here.

2220 GMT (5:20 p.m. EST)

Endeavour mission specialist no. 1 Mike Lopez-Alegria has just climbed through the hatch. He will be seated on the flight deck aft right seat. Read Lopez-Alegria's bio here.

Meanwhile, a red team has been dispatched to the pad to examine some actuators associated with the Orbiter Access Arm. The arm is swung away from the shuttle at T-minus 7 minutes, 30 seconds. But it also must be able to move back into position very quickly in the event the astronauts need to evacuate the orbiter.

2207 GMT (5:07 p.m. EST)

Expedition 6 commander Ken Bowersox, the mission specialist No. 3 for launch, has boarded the shuttle and taken his left seat on the mid deck. Read Bowersox's bio here.

2202 GMT (5:02 p.m. EST)

Commander Jim Wetherbee, a veteran of five previous shuttle missions, was the first to climb aboard Endeavour. He has taken his front-left seat on the flight deck. Read Wetherbee's bio here.

Next came mission specialist No. 4 and Expedition 6 flight engineer Nikolai Budarin. His position is the right seat on the mid deck. Read Budarin's bio here.

And most recent to board was pilot Paul Lockhart, taking his front right seat on the flight deck. This is Lockhart's second shuttle mission of the year. He stepped in to replace Gus Loria on this mission. NASA says Loria was removed from the flight after he injured his back at home. Read Lockhart's bio here.

2139 GMT (4:39 p.m. EST)

The astronauts have arrived at launch pad 39A.

The crew will take the elevator to the 195-foot level of the pad structure where the Orbiter Access Arm is located with the White Room. In the White Room the crew will be outfitted with the rest of their gear and communications hat before entering Endeavour's crew module hatch.

2132 GMT (4:32 p.m. EST)

The "AstroVan" with the astronauts aboard just drove past the Kennedy Space Center Press Site en route to launch pad 39A.

The crew departed their quarters at the Operations & Checkout Building in Kennedy Space Center's Industrial Area bound around a little while ago and boarded the "AstroVan" for the 20-minute ride to the pad located on the edge of the Atlantic Ocean, about 10 miles away.

2120 GMT (4:20 p.m. EST)

T-minus 3 hours and counting. The countdown has resumed on scheduled from this planned two-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. Liftoff remains set for 8:15:30 p.m. EST.

At the time of launch, the orbiting International Space Station will be flying over the Pacific Ocean, due west of Ecuador. Docking of Endeavour to the station is expected around 5:19 p.m. EST Sunday, given an on-time launch tonight.

2050 GMT (3:50 p.m. EST)

The astronauts are currently receiving a weather briefing by the Spaceflight Meteorology Group at Mission Control. The latest forecast is still calling for problems at Zaragoza tonight -- with the chance of showers within 20 nautical miles and light turbulence. At Moron, forecasters are expecting low cloud ceilings, rain and light turbulence. One of the two sites must have acceptable weather for Endeavour to be permitted to launch.

Making the meteorologists' jobs more difficult is the fact they have to give their "go/no go" call on weather before launch time, almost an hour before the time Endeavour would attempt an emergency landing at one of the Spanish sites.

2020 GMT (3:20 p.m. EST)

Endeavour's external fuel tank is now full with 528,000 gallons of super-cold liquid oxygen and liquid hydrogen. Tanking was completed at about 3:14 p.m. EST.

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 are being dispatched to the pad to perform their jobs. The closeout crew will ready Endeavour'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 from fueling.

1920 GMT (2:20 p.m. EST)

T-minus 3 hours and holding. Countdown clocks have entered a planned two-hour built-in hold. Liftoff remains scheduled for 8:15:30 p.m. EST (0115:30 GMT) tonight from Kennedy Space Center, weather permitting. There are no technical issues being reported by NASA.

1900 GMT (2:00 p.m. EST)

Fueling of Endeavour continues. No problems have been reported as tanking passes the half-way point. The weather here in Florida is near-perfect. But at the abort sites in Spain, it is raining at Zaragoza and ugly in Moron. The only hope at this point is Zaragoza clears enough by launch time.

The launch team is pumping a half-million gallons of cryogenic oxygen and hydrogen into Endeavour's external fuel tank. There are actually two tanks inside the orange 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 Endeavour's aft compartment and finally into the external fuel tank.

1725 GMT (12:25 p.m. EST)

Technicians have begun pumping rocket fuel into space shuttle Endeavour's bullet-shaped external tank for tonight's blastoff at 8:15 p.m. EST. The earlier gaseous nitrogen purge valve issue has been put to rest. A team went out to the pad, ran some tests and found no problems, a NASA spokesman said.

The three-hour shuttle fueling process got underway at 12:14 p.m. EST. The hazardous operation will see 528,000 gallons of super-cold liquid hydrogen and liquid oxygen loaded into the external tank to fuel Endeavour's three main engines during the 8 1/2 minute climb to orbit.

So as the countdown rolls on, the wildcard tonight will be weather at overseas abort landing sites in Spain. Moron is solidly "no go" and Zaragoza has an "iffy" forecast at best. One of the sites must be available for Endeavour to make an emergency landing if a major problem occurs during launch.

1715 GMT (12:15 p.m. EST)

Still waiting on word that tanking has started.

1645 GMT (11:45 a.m. EST)

Workers have apparently resolved the nitrogen valve issue at the launch pad. The purge valve is needed during an on-pad abort. A "go" to begin fueling Endeavour has been given by managers.

1600 GMT (11:00 a.m. EST)

A special "red crew" has been dispatched to launch pad 39A to troubleshoot a gaseous nitrogen valve on the mobile launcher platform. The valve in question is needed for purging. It isn't clear how long it might take to fix this valve. Fueling of Endeavour -- which can't start until that crew has left the pad -- needs to start by about 1:30 p.m. EST to preserve an on-time launch tonight.

1555 GMT (10:55 a.m. EST)

Fueling of space shuttle Endeavour is being delayed by about a half-hour, a NASA spokesperson said, apparently by a technical issue. More details as we get them.

1500 GMT (10:00 a.m. EST)

NASA mission managers will be meeting this hour to discuss the status of the countdown and reivew the weather forecast before giving the launch team a "go" to start loading Endeavour's external fuel tank with a half-million gallons of super-cold liquid hydrogen and liquid oxygen propellants. Tanking could begin by 10:50 a.m.

The key concern going into tonight's launch attempt is the predict bad weather at emergency landing sites in Spain. At least one of the two abort sites -- Zaragoza or Moron -- must have acceptable weather or else Endeavour will not launch. The shuttle would use one of the sites shortly after liftoff in the event of a main engine failure.

The latest update from forecasters in Mission Control indicates there will be showers within 20 nautical miles at Zaragoza and low clouds, showers and visibility concerns at Moron.

0100 GMT (8:00 p.m. EST Thurs.)

Countdown clocks are currently in the T-minus 11 hour built-in hold. Here is a look ahead at the key events remaining in the count: (all times EST)

• Move Rotating Service Structure to the park position (about 12:00 a.m.)
• Perform ascent switch list
• Fuel cell flow-through purge complete
• Resume countdown at T-11 hours (4:20 a.m.)
• Activate the orbiter's fuel cells (5:30 a.m.)
• Clear the blast danger area of all nonessential personnel
• Switch Endeavour's purge air to gaseous nitrogen (6:35 a.m.)
• Enter planned 2-hour built-in hold at the T-6 hour mark (9:20 a.m.)
• Clear pad of all personnel
• Begin loading the external tank with about 500,000 gallons of cryogenic propellants (as early as 10:50 a.m.)
• Resume countdown at T-6 hours (11:20 a.m.)
• Complete filling the external tank with its flight load of liquid hydrogen and liquid oxygen propellants (about 1:55 p.m.)
• Final Inspection Team proceed to launch pad
• Enter planned 2-hour built-in hold at T-3 hours (2:20 p.m.)
• Perform inertial measurement unit preflight calibration
• Align Merritt Island Launch Area (MILA) tracking antennas
• Perform open loop test with Eastern Range
• Resume countdown at T-3 hours (4:20 p.m.)
• Begin Eastern Range final network open loop command checks
• Primary ascent guidance data is transferred to the backup flight system
• Complete inertial measurement unit preflight alignments
• Enter planned 10-minute hold at T-20 minutes (7:00 p.m.)
• Transition the orbiter's onboard computers to launch configuration
• Start fuel cell thermal conditioning
• Close orbiter cabin vent valves
• Transition backup flight system to launch configuration
• Resume countdown at T-20 minutes (7:10 p.m.)
• Enter estimated 45-minute hold at T-9 minutes (7:21 p.m.)
• Launch Director, Mission Management Team and NASA Test Director conduct final polls for go/no go to launch
• Resume countdown at T-9 minutes (about 8:09 p.m.)
• Start Auxiliary Power Units (T-5:00)
• Ground Launch Sequencer go for auto sequence start (T-0:31 seconds)
• Ignition of three Space Shuttle main engines (T-6.6 seconds)
• SRB ignition and liftoff (T-0)

0001 GMT (7:01 p.m. EST Thurs.)

NASA has revealed Friday's launch window for space shuttle Endeavour's flight to the space station. The 10-minute window will extend from 8:10:31 to 8:20:30 p.m. EST. The preferred liftoff time will be 8:15:30 p.m. EST when the station's orbital plane is directly over Endeavour's launch pad.

See the NASA Television schedule here.

THURSDAY, NOVEMBER 21, 2002

Here's the latest from Bill Harwood:

With concerns about Endeavour's damaged robot arm behind them, engineers are marching smoothly through the shuttle's countdown to a delayed launch Friday on a space station assembly mission. There are no technical problems at pad 39A and forecasters are predicting an 80 percent chance of good weather in Florida. The only local concern is the possibility of high crosswinds at the shuttle's emergency runway.

But it's a different story overseas. Low clouds, showers and turbulence are expected at or near Endeavour's two emergency landing sites in Spain, where commander James Wetherbee would have to attempt a return to Earth in the event of a main engine failure midway into the climb to orbit.

One of the Spanish runways - either at Zaragoza or Moron - must be available for a shuttle to be cleared for flight. For Friday night, forecasters are predicting a chance of showers within 20 nautical miles of Zaragoza with low ceilings, clouds and turbulence at Moron.

Even so, launch managers are optimistic about finally getting Endeavour off the ground.

"The count's going real well," NASA test director Steven Altemus said in a telephone interview. "With those (robot arm and oxygen leak) issues we put behind us yesterday, we're feeling really good about our chances. I think we're on the border of what they call 'the plus side of iffy' on Zaragoza. So Zaragoza may come in for us."

The trans-Atlantic landing weather in Spain is expected to be marginal to no-go throughout the weekend. Florida's weather will improve to 95 percent "go" if launch is delayed to Saturday but conditions will deteriorate somewhat as the weekend progresses, with forecasters calling for a 40 percent chance of a delay if launch slips to Sunday.

MONDAY, NOVEMBER 11, 2002

Launch of the shuttle Endeavour on a space station assembly mission is off at least a week - and possibly longer - because of troubleshooting to fix a leak in one of two systems that feed oxygen to the ship's crew cabin. But the delay to the evening of Monday, November 18, is a best-case scenario and launch could slip even more depending on what is actually needed to fix the problem. Read our full story.

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

NASA is holding the post-scrub news conference at this moment here at Kennedy Space Center. Shuttle program manager Ron Dittemore says launch will be delayed until the evening of November 18.

This evening, the launch team noted a one-pound per hour leak of oxygen from one of the two oxygen feed systems to the shuttle's crew cabin. Both systems were last checked when Endeavour was in the hangar and were OK. But when valves were opened this evening to flow oxygen to the cockpit, the leak was found. Troubleshooting made it clear that the launch would have be postpone to understand what has caused the leak.

Plans call for workers to access the orbiter's mid-body area, beneath the payload bay, this week for inspections and repairs. At this point, officials believe the P1 truss structure won't have to be removed from the payload bay because the area that workers need to reach is above the cargo.

If all goes well, the shuttle's fuel cells will be serviced and another countdown started in a few days.

0354 GMT (10:54 p.m. EST Sun.)

The engineering meeting is now underway. Spokespeople say the leak is likely on the primary oxygen loop to the shuttle's cabin. It is expected that the P1 truss will have to removed from the payload bay of Endeavour to gain access to the leaky line for repairs. The line is located in the orbiter's mid-body. Launch would be delayed at least week under such a scenario. But all is speculation at this point. A NASA briefing for reporters is expected later tonight.

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

The flight crew, riding in the Astrovan, has driven away from the launch pad.

An engineering meeting is scheduled for 10:45 p.m. EST tonight to discuss the oxygen leak. A NASA news conference will follow tonight.

To recap, there is an oxygen leak in one of two feed lines to the crew module. It is not known how the leak started or whether it would grow during the vibrations of launch. So given the uncertainty tonight, officials had no choice but to scrub for the day.

The leak is located in the mid-body of Endeavour, beneath the payload bay. So gaining access to this area on the launch pad won't be the easiest thing to do.

0303 GMT (10:03 p.m. EST Sun.)

Here's the conversation between NASA Test Director Steve Altemus and Endeavour commander Jim Wetherbee:

"I'd like to welcome you aboard, WX, but tonight's not our night," Altemus said. "The MMT has declared a scrub for a potential leak in the O2 system. We're going to continue to troubleshoot that tonight and try to understand where we're at with that before we declare the length of the scrub necessary here. I know you guys are going to be disappointed but I think we want to give you a healthy vehicle before we cut you loose from the Cape here."

"Absolutely, you guys are doing great. Thank you," Wetherbee replied from the cockpit.

0301 GMT (10:01 p.m. EST Sun.)

Commander Wetherbee and cosmonaut Nikolai Budarin are now off the shuttle.

0300 GMT (10:00 p.m. EST Sun.)

NASA is planning a news conference in a couple hours to provide more information about this oxygen leak. And NASA commentator George Diller in the launch control center now says another shot at launch in 24 hours in rather unlikely -- that a longer delay is expected at this point.

0253 GMT (9:53 p.m. EST Sun.)

The Expedition 5 crew aboard the international space station has just been radioed the news of tonight's scrub.

Commander Jim Wetherbee, already strapped into his seat in Endeavour, just spoke with NASA Test Director Steve Altemus in the firing room. The team is developing a plan to troubleshoot this mysterious oxygen leak tonight. Although NASA is protecting the option of launching tomorrow night, the exact length of the delay won't be known until more information about the leak is determined.

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

The launch team has been told to prepare for another launch attempt tomorrow night. However, that is just to protect their options and a longer delay may very well occur.

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

SCRUB! Tonight's launch attempt has been scrubbed due to the oxygen leak to the shuttle's crew cabin.

The crew members that had already boarded Endeavour will now come off the shuttle. And later tonight the shuttle's external tank will be drained. There is no word on how long this delay might last.

Watch this page for the very latest.

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

Mission specialist No. 4 and Expedition 6 flight engineer Nikolai Budarin has boarded the shuttle and taken his right seat on the mid deck. Read Budarin's bio here.

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

Commander Jim Wetherbee has climbed aboard the shuttle and taken his front-left seat on the flight deck. Read Wetherbee's bio here.

Meanwhile, the Mission Management Team is about to convene a meeting to discuss this oxygen leak aboard Endeavour. Engineers say the leak is on one of two feed lines in the shuttle's mid-body that supply oxygen to the crew cabin. It remains to be seen if this is a significant enough issue to halt tonight's launch.

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

NASA has lifted the remaining secrecy surrounding the countdown by announcing the Endeavour astronauts have arrived at launch pad 39A.

The crew took the elevator to the 195-foot level of the pad structure where the Orbiter Access Arm is located with the White Room. In the White Room the crew will be outfitted with the rest of their gear and communications hat before entering Endeavour's crew module hatch.

Meanwhile, the launch team is now assessing an oxygen leak in the crew cabin that feeds the crew's helmets during liftoff. It is unknown how this problem will impact tonight's launch attempt. The concern is the leak could get worse during the vibrations of launch.

0220 GMT (9:20 p.m. EST Sun.)

The "AstroVan" with the astronauts aboard just drove past the Kennedy Space Center Press Site en route to launch pad 39A.

The crew departed their quarters at the Operations & Checkout Building in Kennedy Space Center's Industrial Area bound around a little while ago and boarded the "AstroVan" for the 20-minute ride to the pad located on the edge of the Atlantic Ocean, about 10 miles away.

The AstroVan convoy stopped at the Launch Control Center for some members of NASA management and officials to exit. The managers will take their positions in the Firing Room.

0203 GMT (9:03 p.m. EST Sun.)

T-minus 3 hours and counting. The countdown has resumed on scheduled from this planned two-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. Liftoff remains set for 12:58:40 a.m. EST.

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

Now entering the final five hours to the launch of Endeavour. All launch weather rules are currently within limits.

Endeavour stands fully fueled with liquid hydrogen and liquid oxygen. Filling of the external tank officially began at 4:32 p.m. and was completed at 7:27 p.m. EDT.

Following tanking procedures, a team called the Final Inspection Team was dispatched to the pad to check the vehicle one last time prior to liftoff. The team, comprised of engineers and a safety official, is currently performing the inspections at pad 39A. At the conclusion of their two-hour tour-of-duty, they 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 that could break-off during ignition and damage the spacecraft. The team is also searching for any loose debris that could possibly fly up and strike the vehicle at launch. And the third item of interest to the team is the thermal 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. One team member is also responsible for photo documentation.

Each member of the Final Inspection Team is in constant contact with NASA Test Director Steve Altemus in the Firing Room.

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.

Following the Final Inspection Team's activities, they will meet with NASA Launch Director Mike Leinbach, the Mission Management Team, and engineering directors in the launch control center, providing a detailed report on the inspections and findings at the pad 39A.

A full inspection of the vehicle and pad was performed yesterday and the external tank received a thorough check prior to fueling today.

An inspection of the launch pad and beach will be made following launch. That inspection will be to look for anything unusual, particularly anything that could have fallen off of the vehicle during the first few seconds of flight. Later, there will be a meeting to review high-speed videotape and film of the launch and early ascent to determine if there was any damage to the vehicle.

0034 GMT (7:34 p.m. EST Sun.)

Good evening from Kennedy Space Center where all systems are "go" for tonight's launch of space shuttle Endeavour. Countdown clocks are currently holding at T-minus 3 hours for a two-hour planned hold. Liftoff is still set for 12:58:40 a.m. EST.

Endeavour's external fuel tank is now full with 528,000 gallons of super-cold liquid oxygen and liquid hydrogen. Tanking was officially completed at 7:27 p.m. EST.

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 are being dispatched to the pad to perform their jobs. The closeout crew will ready Endeavour'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 from fueling.

SUNDAY, NOVEMBER 10, 2002
2305 GMT (6:05 p.m. EST)

Fueling of Endeavour continues. No problems have been reported as tanking nears the half-way point.

The launch team is pumping a half-million gallons of cryogenic oxygen and hydrogen into Endeavour's external fuel tank. There are actually two tanks inside the orange 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 Endeavour's aft compartment and finally into the external fuel tank.

2137 GMT (4:37 p.m. EST)

Technicians have begun pumping cryogenic rocket fuel into space shuttle Endeavour's bullet-shaped external tank for tonight's blastoff at 12:59 a.m. EST. The minor camera issue has been put to rest so there are now no problems being worked by the launch team, NASA reports, and the weather forecast is favorable.

The three-hour shuttle fueling process got underway at 4:32 p.m. EST. The hazardous operation will see 528,000 gallons of super-cold liquid hydrogen and liquid oxygen loaded into the external tank to fuel Endeavour's three main engines during the 8 1/2 minute climb to orbit.

2103 GMT (4:03 p.m. EST)

T-minus 6 hours and counting. The countdown clock at Complex 39 has resumed after a two-hour planned hold. The count will now proceed to the T-minus 3 hour mark where another two-hour hold is scheduled.

2100 GMT (4:00 p.m. EST)

Tanking operations remain on hold for the moment while the camera problem is fixed. NASA says the launch team has until around 6 p.m. to start fueling without impacting the launch time.

2038 GMT (3:38 p.m. EST)

Fueling of Endeavour should begin shortly. Technicians are trying to fix a camera at the launch pad. Although not a requirement for fueling, the camera is something the launch team would like to have working. So the repair efforts have held up tanking briefly this afternoon.

Meanwhile, weather officials say the forecast for launch time has improved to a 90 percent chance of acceptable conditions for liftoff at 12:59 a.m. EST.

1903 GMT (2:03 p.m. EST)

T-minus 6 hours and holding. The countdown clock has entered a planned two-hour hold as preparations continue for tonight's launch of space shuttle Endeavour on an 11-day mission to the international space station.

The Mission Management Team will be convening their pre-tanking meeting in a little while to review the status of the shuttle, station, ground systems and weather. If there are no problems, the "go" will be given to start fueling Endeavour's external tank with a half-million gallons of super-cold liquid hydrogen and liquid oxygen around 3:30 p.m. EST.

Watch this page for updates throughout the evening and the entire flight of Endeavour.

0001 GMT (7:01 p.m. EST Sat.)

NASA has revealed Monday's launch window for space shuttle Endeavour's flight to the space station. The 10-minute window will extend from 12:53:39 to 1:03:39 a.m. EST (0553:39-0603:39 GMT). The preferred liftoff time will be 12:58:40 a.m. EST (0558:40 GMT) when the station's orbital plane is directly over Endeavour's launch pad.

With no technical problems being worked, the countdown remains on schedule for liftoff. Air Force meteorologists are calling for an 80-percent chance of good launch weather.

Here is a look ahead at the key events in the count: (all times EST)

• Move Rotating Service Structure to the park position (about 5:00 a.m.)
• Perform ascent switch list
• Fuel cell flow-through purge complete
• Resume countdown at T-11 hours (9:03 a.m.)
• Activate the orbiter's fuel cells (10:13 a.m.)
• Clear the blast danger area of all nonessential personnel
• Switch Endeavour's purge air to gaseous nitrogen (11:18 a.m.)
• Enter planned 2-hour built-in hold at the T-6 hour mark (2:03 p.m.)
• Clear pad of all personnel
• Begin loading the external tank with about 500,000 gallons of cryogenic propellants (about 3:30 p.m.)
• Resume countdown at T-6 hours (4:03 p.m.)
• Complete filling the external tank with its flight load of liquid hydrogen and liquid oxygen propellants (about 6:30 p.m.)
• Final Inspection Team proceed to launch pad
• Enter planned 2-hour built-in hold at T-3 hours (7:03 p.m.)
• Perform inertial measurement unit preflight calibration
• Align Merritt Island Launch Area (MILA) tracking antennas
• Perform open loop test with Eastern Range
• Resume countdown at T-3 hours (9:03 p.m.)
• Complete close-out preparations in the white room
• Check cockpit switch configurations
• Begin Eastern Range final network open loop command checks
• Primary ascent guidance data is transferred to the backup flight system
• Complete inertial measurement unit preflight alignments
• Enter planned 10-minute hold at T-20 minutes (11:43 p.m.)
• NASA Test Director conducts final launch team briefings
• Transition the orbiter's onboard computers to launch configuration
• Start fuel cell thermal conditioning
• Close orbiter cabin vent valves
• Transition backup flight system to launch configuration
• Resume countdown at T-20 minutes (11:53 p.m.)
• Enter estimated 46-minute hold at T-9 minutes (12:04 a.m.)
• Resume countdown at T-9 minutes (about 12:50 a.m.)
• Start automatic ground launch sequencer (T-9:00 minutes)
• Start Auxiliary Power Units (T-5:00)
• Ground Launch Sequencer go for auto sequence start (T-0:31 seconds)
• Ignition of three Space Shuttle main engines (T-6.6 seconds)
• SRB ignition and liftoff (T-0)

Read our earlier status center coverage.