BY SPACEFLIGHT NOW

December 5, 2000 -- Follow the four-month mission of first resident crew of the international space station as well as the STS-97 flight of space shuttle Endeavour to deliver the first solar array module to the orbiting outpost. Reload this page for the very latest.

FRIDAY, DECEMBER 8, 2000

During launch of shuttle Endeavour November 30, one of two explosive cartridges used to separate a strut holding the base of the orbiter's left-side solid-fuel booster to the ship's external fuel tank failed to fire. Read our full story.

2300 GMT (6:15 p.m. EST)

The space station's new solar wings responded to shuttle jet firings today in a structural dynamics test exactly as expected. In addition, an instrument installed at the top of the P6 solar power tower during a spacewalk Thursday was turned on today and initial data indicates there is no dangerous buildup of electrical charges on the huge arrays.

Two instruments called plasma contactors are attached to the station's hull to eliminate the buildup of potentially dangerous charges as the station plows through the charged particle environment of the extreme upper atmosphere.

The plasma contactors work by spewing a steady stream of xenon atoms into space, closing a huge circuit to prevent any buildup that could, in theory at least, injure - or kill - a spacewalking astronaut.

While flight controllers know the plasma contactors are working, the station was not equipped with any instrumentation showing just how well they are mitigating charge buildup.

Concerned about the potential threat to spacewalkers, NASA added an instrument called a floating potential probe to Endeavour's cargo at the last minute and it was installed on the P6 array Thursday.

Lead flight director William Reeves said today the FPP was activated and showed the plasma contactors keeping the charge buildup minimal.

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

We have posted video of the Endeavour crew boarding the space station.

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

Hatches between the shuttle Endeavour and the international space station were finally opened today, allowing the two crews to meet fact-to-face for the first time since the orbiter docked last Saturday.

Shuttle skipper Brent Jett and station commander William Shepherd - both graduates of the U.S. Naval Academy - greeted each other in traditional Navy fashion at 9:36 a.m. as the two spacecraft sailed 240 miles above the southern Pacific Ocean.

"Alpha, Endeavour, the crew requests permission to come aboard," Brent formally requested before floating through the last hatch into the station's Unity module.

"Endeavour, permission granted," Shepherd replied.

Jett and his crewmates -- pilot Michael Bloomfield, Canadian Marc Garneau and spacewalkers Joseph Tanner and Carlos Noriega -- then floated into the roomy multi-hatch connecting module, smiling, shaking hands and sharing hugs with Shepherd and his two crewmates, Sergei Krikalev and Yuri Gidzenko.

"On behalf of the crew on Alpha, I would like to commend Endeavour and its crew on the tremendous technical challenge and the great achievement of putting (the) P6 (solar power system) together," Shepherd radioed ground controllers. "We really appreciate it. I can't think of a mission that we've flown for a long time that's been a bigger challenge. It's been awesome."

The station crew then followed their shuttle colleagues up to Endeavour's flight deck to get their first good look at the space station's new P6 solar power tower and its two huge wings through a pair of large overhead windows.

"And they're pretty impressed with the arrays," Jett radioed and Shepherd, Gidzenko and Krikalev admired the view.

The station crew then returned the favor, leading Jett and company back into the space station for a tour of the Russian-built, NASA-financed Zarya module and the Zvezda command module where Shepherd, Gidzenko and Krikalev live and work. Television cameras mounted along the way allowed flight controllers -- and the public -- to follow along.

Stopping again in the Unity module, the crews paused for more pictures. At one point, six different still and video cameras could be seen as the astronauts and cosmonauts took pictures of each other. Then they floated through hatch into Zarya and headed for Zvezda at the far end of the station.

After a safety review to brief the shuttle astronauts on space station procedures, the joint crews planned to get down to work, transferring equipment and supplies and carrying out tests to measure the station's response to shuttle jet firings.

For Tanner -- another Navy veteran -- getting a chance to explore the space station is a dream come true.

"First of all, we want to go in and see what the station feels like," he said in a pre-launch NASA interview. "We want to get in there and just get the atmosphere of the place. I didn't get a chance to go to Mir on my other two flights, and Carlos and, I think, Mike and Brent have all been there, and so I want to see what a station is like."

But there won't be much time for sightseeing. The hatches will be closed Saturday morning and the shuttle will undock later that afternoon. In between, the two crews will be busy transferring equipment and supplies from the shuttle to the station and moving trash and no-longer-needed equipment from the station to Endeavour.

"We have some transfers to complete," Tanner said. "We'll bring over more water, we'll take the equipment back that they are done with and put it back on the shuttle for return to Earth. And I think we'll just be enjoying their company a lot."

1437 GMT (9:37 a.m. EST)

Following full navy tradition the space shuttle Endeavour astronauts boarded the international space station at 1436 GMT (9:36 a.m. EST). They are the first visitors to the complex since the arrival of the station's first inhabitants just over a month ago.

1255 GMT (7:55 a.m. EST)

The Endeavour astronauts were awakened at 7:08 a.m. to begin a busy day of work to transfer equipment and supplies into the international space station. Commander Brent Jett plans to open a final hatch between the shuttle and the station at 9:36 a.m., allowing the two crews to greet each other face to face for the first time.

Jett and station skipper William Shepherd, both Navy veterans, have some sort of formal greeting ceremony planned, but the details have not been revealed.

"Well, we might have something planned," Jett said before launch. "Shep and I have talked a little bit about some of the Navy traditions and whether or not those would be appropriate to establish for the space station; you'll just to have to tune in and find out what happens.

"We'll do our best to get TV down during that, because we know there's a high amount of interest in that particular activity. But you know, our main goal is just going to be to get in and start, you know, see Shep and his crew and give them a chance if they want to come over to the shuttle for a little more room than they've had on station to do that as well. So I think it'll be interesting."

The two crews will only have one day of joint operations before the shuttle hatches will be resealed for undocking Saturday afternoon.

Along with transferring equipment and supplies from the shuttle to the station, unneeded gear and trash will be moved from the station to the shuttle for return to Earth. In addition, Jett plans to fire Endeavour's small maneuvering jets later this morning in a structural test to study how the station - and its new solar array wings - respond to dynamic loads.

A centerline camera system that will be used in January to help install the U.S. laboratory module, Destiny, will be checked out later this today and Shepherd will use a large-format IMAX camera to film "day-in-the-life kinds of scenes for a future IMAX production," said station flight director Jeff Hanley.

"The (equipment and supplies) transfer operations really are the primary objectives of the activity," he said. "The rest of the time will be spent with the crews spending some time together just to swap stories over the last few days, have a meal together, there'll be a crew (news) conference with the ground and then we'll just leave them alone to socialize a little bit."

The two crews have not been able to meet until now because the shuttle's cabin air pressure was lowered to 10.2 pounds per square inch - equivalent to an altitude of 10,000 feet on Earth - shortly after launch to help spacewalkers Joseph Tanner and Carlos Noriega avoid decompression problems when using their 5 psi spacesuits. After the conclusion of their third spacewalk Thursday, Endeavour's air pressure was raised back up to 14.7 psi to match the station's, clearing the way for hatch opening later this morning.

THURSDAY, DECEMBER 7, 2000
2126 GMT (4:26 p.m. EST)

Space shuttle Endeavour's airlock is now being repressurized, ending a highly successful spacewalk by astronauts Joe Tanner and Carlos Noriega that repaired the limp space station starboard solar array wing. The excursion ended at 4:23 p.m. EST, bringing the total elapsed EVA time today to 5 hours and 10 minutes.

Today's spacewalk marked the 95th in the history of the U.S. space program, the 57th from a space shuttle and third and final planned on this mission of STS-97. It was the fifth EVA for Joe Tanner and the third for Carlos Noriega.

The total spacewalk time for this flight of Endeavour over the three EVAs is 19 hours and 20 minutes.

2119 GMT (4:19 p.m. EST)

The airlock outer hatch has been closed and today's spacewalk will officially conclude once repressurization begins in the next few minutes.

2100 GMT (4:00 p.m. EST)

Today's spacewalk is winding down with the crew back in Endeavour's payload bay near the airlock stowing tools and equipment. They have completed all their major tasks and will soon conclude the excursion.

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

The spacewalkers are attaching their portable foot restraint platforms to the station's exterior for use by future crews. In addition, they are preparing to install some temperature sensors to the station's P6 cooling radiator and cone-shaped Wireless Instrumentation System antennas to the complex, which are "get-ahead tasks" being added by Mission Control today because the spacewalk has gone so well and ahead of the timeline.

1956 GMT (2:56 p.m. EST)

The Floating Potential Probe has been installed to the top of the international space station, completing the final planned task of today's ongoing spacewalk by Joe Tanner and Carlos Noriega. A picture of evergreen tree adorns the side of the probe in honor of a tradition to place such a tree atop any new construction project.

With the spacewalk approaching nearly four hours in duration, the two men will now move on to mounting some communications antennas to the station before calling it a day and returning to Endeavour's airlock.

1930 GMT (2:30 p.m. EST)

The spacewalkers have installed the antenna for the Floating Potential Probe to the Unity node and are now making their way to the top of the space station's new P6 solar array truss where the small device will be mounted. The probe is currently disassembled in a couple of pieces. The spacewalkers will put it together and attach the probe to a stand on the very tip of the 49-foot tall P6 truss.

Meanwhile, Mission Control has decided to add a few additional tasks for this spacewalk since Tanner and Noriega are running significantly ahead of schedule. The extra work will include installing wireless data antennas to the station.

1853 GMT (1:53 p.m. EST)

The protective panel on the Unity node's hull has been reattached as the spacewalkers continue steps to install the Floating Potential Probe. From today's preview story:

The probe was designed to measure how well two other components, called plasma contactors, are working to keep potentially dangerous electrical charges from building up.

As the station plows through charged particles in the extreme upper atmosphere, its new solar arrays will build up an electrical charge. The plasma contactors emit a steady stream of xenon atoms to close a giant space circuit, eliminating that potential.

Without the contactors, a spacewalking astronaut could get receive a potentially dangerous -- perhaps deadly -- shock from a sudden discharge.

The plasma contactors are on and performing normally as far as anyone can tell. But there are no instruments to measure the electrical environment around the station. The floating potential probe will do just that, presumably proving once and for all that lightning bolts are not on the list of threats spacewalkers need fear.

To be on the safe side, however, the P6 solar arrays will be "shunted" during the spacewalk today and oriented edge on to the station's direction of travel to minimize any electrical buildup.

1827 GMT (1:27 p.m. EST)

The spacewalkers have temporarily removed a section of the micro-meteor shield on the U.S. Unity node and some thermal blankets to gain assess to electrical connectors in preparation for the Floating Potential Probe installation today.

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

The television cable has been connected for the centerline video camera to be used during attachment of the U.S. Destiny science laboratory in January, completing another chore in today's spacewalk.

The spacewalk's remaining objective is mounting the so-called Floating Potential Probe atop the P6 solar array tower. The device will measure the electrical potential of plasma around the international space station.

1813 GMT (1:13 p.m. EST)

Now two hours into today's spacewalk.

1803 GMT (1:03 p.m. EST)

Here is the exchanges between the shuttle crew and Mission Control when the second and final tension cable had been re-threaded to its reel:

"We have completed the interior tensioning reel and it was just like the outer one and it looks nominal," Marc Garneau, coordinating the spacewalk from Endeavour's cockpit, told Houston after both cables had been put back on their reels.

"That is absolutely outstanding work," replied astronaut Shannon Lucid in mission control.

"Joe and Carlos are quite the team," Garneau said. "And we might add all the hard work that's been done by the ground to come up with this procedure."

"Yeah, that procedure they gave us was fantastic, it was perfect," added Noriega.

"This was almost - I'm not going to say a no brainer because everyone would make fun of me for not having one - but it was perfect," Tanner agreed.

"Well Endeavour, Houston, the ground is ecstatic," Shannon said.

1754 GMT (12:54 p.m. EST)

With the solar array fix now complete, the spacewalkers are moving ahead to their other planned tasks. The next job will be the routing of a television cable on the station that will used during the shuttle flight in January when the Destiny laboratory module is mounted to the outpost.

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

The spacewalkers are now removing their portable foot restraint platforms and preparing to move clear of the solar arrays. Today's repair has gone extremely well and fast. Mission controllers had set aside about three hours to make the repairs but the spacewalkers finished the job less than 90 minutes after beginning their excursion.

1738 GMT (12:38 p.m. EST)

The newly-fixed right-hand solar array blanket on the starboard wing has been tensioned, bringing to an end the successful repair job 235 miles above the Earth by spacewalking astronauts Joe Tanner and Carlos Noriega. The international space station's two solar array wings spanning 240 feet are now completely taut and fully operational.

1736 GMT (12:36 p.m. EST)

The left blanket is now tightened. This is the blanket next to the one the spacewalkers repaired today.

1735 GMT (12:35 p.m. EST)

The wing has been fully deployed to its near 115-foot length. Tensioning of the left solar array blanket is starting.

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

Redeployment has started. The tensioning reels are turning as planned, the spacewalkers report.

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

Endeavour's crew has just been given a "go" to redeploy the starboard solar array wing, which was retracted about three feet to aid in the spacewalker's repair today. Once fully extended, the solar array blankets will be tensioned.

1723 GMT (12:23 p.m. EST)

Moving extraordinarily swiftly, the spacewalkers have successfully reattached the second solar blanket tensioning cable to its reel, completing the repair effort to the international space station's new solar wing. The wing will be redeployed shortly and the blankets tensioned for the first time.

1714 GMT (12:14 p.m. EST)

Now passing one hour into today's scheduled six-hour spacewalk. Tanner and Noriega are currently preparing to re-thread the second of two solar array blanket tensioning cables that jumped their reels during solar wing deployment on Sunday evening.

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

Canadian astronaut Marc Garneau just radioed Mission Control and said spacewalkers Tanner and Noriega fixed the outer tension reel on the first try. They are now getting into position to re-thread the inner reel.

1656 GMT (11:56 a.m. EST)

Success on the first reel. That is the report from Endeavour as the spacewalkers have placed one of the two tensioning cables back on its reel.

1653 GMT (11:53 a.m. EST)

Endeavour's steering thrusters have been disabled to ensure there isn't any sudden movement while the spacewalkers handle the solar array tensioning cables.

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

The spacewalkers have reached their work site nearly 90 feet above the space shuttle Endeavour's payload bay. Joe Tanner has placed himself in a portable foot restraint platform and reported his initial inspections of the solar array blanket. He says the tension cables are off their pulleys. Carlos Noriega is now beginning to get into position, also.

1617 GMT (11:17 a.m. EST)

Spacewalkers Joe Tanner and Carlos Noriega have switched their suits from shuttle-supplied power to internal batteries. This milestone --at 11:13 a.m. EST) -- signals the official start of today's spacewalk.

The spacewalk is the 95th in the history of the U.S. space program, the 57th from a space shuttle and third and final planned on this mission of STS-97. It is the fifth EVA for Joe Tanner and the third for Carlos Noriega.

In the next few minutes, the two men will float out of Endeavour's airlock and begin gathering tethers, tool and equipment needed for the spacewalk. They will then head nearly 90 feet above the shuttle's payload bay to the top of the newly-installed P6 solar array truss on the international space station. Priority No. 1 for this spacewalk is to tighten a solar array blanket that was never tensioned after deployment on Sunday because small cables inside the structure designed to bring the blanket taut jumped their pulleys. The spacewalkers' job is to get those cables back on the pulleys. It is a task they have never practiced or simulated on Earth.

1557 GMT (10:57 a.m. EST)

The space station's starboard solar wing has been retracted slightly and two astronauts are suited up and depressurizing the space shuttle's airlock in preparation for today's impromptu spacewalk to repair slack tension wires on a solar array blanket.

Spacewalkers Joe Tanner and Carlos Noriega are about 15 minutes away from beginning their excursion today. Read our full story previewing the spacewalk.

1245 GMT (7:45 a.m. EST)

The Endeavour astronauts were awakened at 7:06 a.m. today to begin preparations for a third, hopefully final, spacewalk by astronauts Joseph Tanner and Carlos Noriega. The excursion is scheduled to begin around noon EST (1700 GMT) and end around 6 p.m. (2300 GMT).

The top priority is to tighten up a loose solar array blanket on the P6 power tower's starboard solar wing. Now-secondary objectives include installation of television equipment to help the next crew attach the U.S. laboratory module, Destiny, in January and an instrument to measure the electrical environment around the outpost.

The space station's three-man crew, meanwhile, has spent the morning preparing equipment for transfer to the shuttle on Friday and rigging the now-open U.S. Unity module for day-to-day use, installing air ducts and activating emergency systems.

WEDNESDAY, DECEMBER 6, 2000
2030 GMT (3:30 p.m. EST)

NASA managers today formally approved a bold plan for two spacewalking astronauts, working nine stories above the shuttle Endeavour, to tighten up a loose solar array blanket, one of four on the international space station's new $600 million solar power tower. Read our full story.

1400 GMT (08:00 a.m. EST)

Space station commander William Shepherd re-entered the U.S. Unity module around 5:30 a.m. today to make preparations for shuttle-to-station and station-to-shuttle equipment transfers Friday. Crewmates Yuri Gidzenko and Sergei Krikalev, meanwhile, are working to repair an air conditioner in the Russian Zvezda command module to reduce high humidity levels in the space station.

Concern about humidity and possible condensation buildups in the Unity module have prompted flight controllers to limit Shepherd's access to the module to just six hours or so. Engineers are assessing whether that time limit can be extended to give the commander more time to complete pre-transfer preparations.

The Endeavour astronauts were awakened at 7:36 a.m. (1236 GMT). The five-man crew faces a relatively light schedule today and plans to enjoy a bit of off-duty time this afternoon. At 1:11 p.m. EST (1811 GMT), the crew will field questions from the Fox News Network, Space.com and Bob Vila Productions.

They also will set up and check out a device that will be installed on the space station during a third and final spacewalk Thursday to monitor the electrical environment around the outpost. The new P6 solar array wings will collect a charge as the station plows through the tenuous extreme upper atmosphere.

Devices called plasma contactors, already attached to the station, emit xenon atoms to allow that charge to dissipate, preventing potentially dangerous arcs, or discharges, that could injure or possibly kill a spacewalking astronaut. The "floating potential probe" that will be installed Thursday will tell engineers just how well the plasma contactors are working.

The astronauts will begin an off-duty period at 4:06 p.m. (2106 GMT) and go to bed at 11:06 p.m. (0406 GMT.

TUESDAY, DECEMBER 5, 2000
0415 GMT (11:15 p.m. EST)

NASA flight controllers briefed the shuttle Endeavour's crew this evening on a still-evolving plan to have spacewalkers Joseph Tanner and Carlos Noriega tighten up a loose solar blanket on the P6 solar array's starboard wing.

The procedure, if approved by NASA's mission management team Wednesday, would be implemented Thursday, during the crew's third and final spacewalk. A detailed story outlining the proposed fix will be posted shortly.

In the meantime, the Endeavour astronauts have called it a day. Along with carrying out a successful spacewalk, the crew also deployed a set of radiator panels on the side of the P6 solar array truss. The deployment originally was scheduled for Wednesday, but it was moved up to lighten the crew's workload.

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

For readers scoring at home, the duration of today's spacewalk was six hours 37 minutes and a few seconds. Given a 12:21 p.m. EST start time, that works out to an ending time of 6:58 p.m. NASA's official stop time, however, is 6:59 p.m.

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

Flight controllers are revising the shuttle crew's timeline for this evening. The astronauts have asked to press ahead with deployment of a set of radiator panels on the side of the P6 solar array truss this evening instead of waiting until Wednesday.

The radiator panels were unlatched during today's spacewalk by Carlos Noriega and Joseph Tanner. A mission status briefing, originally scheduled for 8 p.m. and then moved up to 7:30 p.m., has been pushed back to 8 p.m.

0005 GMT (7:05 p.m. EST)

Astronauts Carlos Noriega and Joseph Tanner began repressurizing the shuttle Endeavour's airlock at 06:59 p.m., officially ending a six-hour 37-minute excursion. It was the 56th spacewalk in shuttle history, the 95th in U.S. space history and the 12th devoted to building the international space station.

Encountering virtually no problems, Tanner and Noriega successfully wired the P6 solar array into the space station's power system; moved an S-band antenna array to its permanent mounting point atop the P6 truss; connected ammonia coolant lines between P6 radiators and the station; and prepared docking port PMA-2 for for relocation during the next assembly flight.

The spacewalkers also installed work platforms for the next station assembly crew, hooked up jumpers allowing power from the P6 array to flow into the Russian and Zvezda modules and released latches to free up a radiator for deployment Wednesday.

A mission status briefing with lead flight director William Reeves, originally planned for 8 p.m., has been moved up to 7:30 p.m. A complete wrapup story will be posted later this evening, along with updated EVA totals.

2335 GMT (6:35 p.m. EST)

The shuttle's robot arm is being cradled as astronauts Joseph Tanner and Carlos Noriega complete cargo bay cleanup work prior to ending a successful spacewalk. Noriega is back in Endeavour's airlock stowing tools and equipment while Tanner makes his way down the space station "stack." The spacewalk will officially end with the start of airlock repressurization.

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

Spacewalkers Tanner and Noriega are wrapping up their second spacewalk. Five hours and 14 minutes into the excursion, the astronauts have completed virtually all of their major objectives and are in the process of completing release of restraints holding a radiator in place.

Space station commander William Shepherd and his crewmates have signed off for the day. During a final tagup with space station control, Shepherd voiced concern about his crew's work schedule, asking NASA managers to work with their Russian counterparts to defer tasks that are not absolutely essential.

Otherwise, he said, the station crew will not be ready Friday - flight day nine - when hatches between the shuttle and station will finally be opened for the combined crews to transfer cargo and supplies.

"What we need to do tomorrow, we need to organize the cargo that's going to go down on 4A (Endeavour) and I need to get on top of IMAX so we can get some shooting done," Shepherd said. "Then on Thursday, we need to try and lay stuff out in the node (Unity module), including the cargo, and set up IWIS (internal wireless instrumentation system).

"Unless we can park the things that are not essential for getting through 4A, we're not going to be ready for flight day nine."

"Shep we copy that and we concur strongly," replied station communicator Joan Higginbotham. "We will do our best to get most of the things that are not 4A related and critical off of your timeline."

2154 GMT (4:54 p.m. EST)

Running a bit ahead of schedule, spacewalkers Carlos Noriega and Joseph Tanner are now four hours and 33 minutes into their second spacewalk. They have completed all electrical connections between the P6 solar arrays and the Z1 truss; relocated the S-band antenna array to the top of P6; connected ammonia coolant lines between P6 and Z1; and readied docking port PMA-2 for removal during a shuttle mission in January.

During that flight, the U.S. laboratory module, Destiny, will be attached to the U.S. Unity module where PMA-2 currently is located. PMA-2 ultimately will be attached to the far end of Destiny for future shuttle dockings.

Noriega currently is releasing cinches holding a set of radiators folded against the side of the P6 central tower. The radiator, one of two that ultimately will be deployed to help cool Destiny's electronic systems, will be extended Wednesday. The other radiator will be extended during the lab installation mission.

Tanner, meanwhile, is working to install so-called "H-jumpers," cables that will permit P6 power to flow into the Russian Zvezda and Zarya modules. Before wrapping up today's spacewalk, the astronauts will mount foot restraints on the station's hull that will be used by the next assembly crew in January.

Engineers at the Johnson Space Center are continuing to assess potential fixes to tighten up a loose solar array blanket on the starboard wing of the P6 power tower. Videotape showing closeup views of the blanket's tensioning system, downlinked earlier from cameras in Noriega's helmet, was replayed on NASA television shortly before 5 p.m., presumably for the benefit of array experts in California.

"Currently a plan being put together that could potentially be used on the third spacewalk of the mission, coming up on Thursday, to work with this tensioning system and increase, tighten basically, the blankets on this solar array," said NASA mission control commentator James Hartsfield.

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

Now three hours and 35 minutes into a planned six-hour spacewalk. Running right on schedule, astronauts Joseph Tanner and Carlos Noriega have completed power line connections between the Z1 truss and the P6 solar arrays.

Station commander William Shepherd, meanwhile, working inside the Unity module, has completed internal connections permitting P6 power to flow into the space station's electrical system. Shepherd then began backing out and sealing the module off while flight controllers carried out a slow warm-up procedure.

"Hopefully, we'll get you in ther permanently tomorrow," astronaut Joan Higginbotham radioed from Houston. "We're shooting for somewhere around lunch time, running around 1300 GMT."

2025 GMT (3:25 p.m. EST)

Joseph Tanner is connecting ammonia coolant lines between the P6 array and the Z1 truss. The coolant lines ultimately will run to the U.S. laboratory module, Destiny, which is scheduled for launch in January.

Worried about leaks, Tanner took his time hooking up ammonia quick-disconnect fittings, following directions from spacewalk coordinator Marc Garneau in the shuttle's cockpit.

"OK, unlock the (quick-disconnect) collar, depress the button and slowly push the bail bar until it locks," Garneau radioed at one point.

"OK. As my dad used to say, here goes nothing," Tanner said. "The collar's unlocked, the button's pushed... moving slowly. No leaks... no leaks... no leaks. The bail bar is pushed all the way, the button is popped up."

"Lock the collar," Garneau reminded.

"The collar's locked."

"OK, that complete's Q-D eight."

"Eight is complete," Tanner confirmed, "Verified it's on eight."

The ammonia lines run to a pair of radiators mounted on the P6 array's central tower. A third radiator, used to dissipate heat generated by the power system's electronics, was deployed Sunday. One of the two main radiator panels will be deployed Wednesday. The other will be extended after the lab module is attached early next year.

Carlos Noriega, meanwhile, is pressing ahead making electrical connections between the P6 array and the Z1 truss, part of a complex procedure to route power from the now deployed solar wings to the rest of the space station.

The work is proceeding smoothly with no significant problems.

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

Joseph Tanner, anchored to the end of the shuttle's robot arm, has mounted a large S-band antenna array atop the space station's P6 solar power tower 90 feet above shuttle Endeavour's cargo bay. He and Carlos Noriega currently are connecting ammonia coolant lines and reconfiguring electrical cables between the P6 array and the Z1 truss.

Earlier, Noriega completed a detailed inspection of the power system's starboard solar wing, beaming down sharp color television images from cameras mounted on his space helmet. One and possibly both of the wing's solar cell blankets failed to pull taut after the wing was extended Sunday.

Tanner reported today that tension cables had jumped off their guide pullies at the base of one blanket.

"The outboard tension is not on the guide pully, it's not going around that pully," Tanner told flight controllers in Houston. "You see? From my angle, I can really see it. ... It probably means the inboard one isn't, either."

"I can't see that it's not on the reel but I can deduce it, because the arc of the cable is different from the arc of the pully itself," Noriega commented.

"We could put it back on that one pully, but the other one is going to be a little work," Tanner said.

Veteran spacewalker Jerry Ross, working with Lockheed solar array engineers in California to develop a possible fix, then asked Noriega to move around the array's central mast to inspect the other blanket making up the starboard solar array wing.

"The guide wires look good, the tension wires have about the same amount of tautness," Noriega reported. "The tension bar looks in good shape as do the ribbon cables."

"OK, copy, and that goes for both the inboard and outboard systems?" Ross asked from mission control.

"That's affirmative."

"OK, guys, what you told us about the side that's not tensioned is about what the guys at Suynnyvale had expected to see and we think we've got, hopefully, a pretty good handle on it and can probably fix it."

"Great!"

Any attempt to tighten up the one loose blanket would not be made until a third and final already planned spacewalk Thursday.

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

The spacewalkers have soft-docked the S-band communications antenna to its final position on the P6 truss.

Meanwhile, Carlos Noriega has moved on to inspect the solar array tension wires on the starboard wing.

Tanner has completed the first phase of power cable reconfiguration between the P6 solar array and the Z1 truss where the array is attached. Many cable connections will be performed during the spacewalk today as circuits are wired in and tests conducted.

The spacewalkers also reported an impact of some sort on one of two cold plates mounted on the side of the Z1 truss. It is not clear whether the impact was caused by a collision with space debris or by spacewalk activity on this or a previous assembly missions.

"It looks like an impact, a point impact on it at one point," Tanner said.

"Could you assess its depth and circumference?" Canadian astronaut Marc Garneau asked from inside Endeavour.

"The impact is about the diameter of a ballpoint pen," Tanner said. "And it's got a scratch emanating about a sixteenth of an inch out one direction, then another scratch that's almost an inch long. It's small, youy can't even see it unless the light's just right."

1825 GMT (1:25 p.m. EST)

Now one hour into today's spacewalk and things are proceeding well. Joe Tanner is making his four EVA and Carlos Noriega is on his second excursion.

The duo are currently releasing the S-band communications antenna mounted to the international space station's Z1 truss for transport to the top of the new P6 truss structure for instellation.

1724 GMT (12:24 p.m. EST)

The second spacewalk of this space shuttle mission officially began at 12:21 p.m. EST. Spacewalkers Joe Tanner and Carlos Noriega have switched their suits from shuttle-supplied power to internal batteries, which signals the EVA start time.

This planned 6.5-hour excursion will see the P6 solar array truss wired to the international space station, the S-band communications antenna relocated and inspections of the tension cables in the starboard solar array.

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

Today's spacewalk is expected to begin about a half-hour early as Joe Tanner and Carlos Noriega are ahead of the timeline. They have about 15 minutes left in the pure-breathing of pure oxygen and then the 15-minute process of depressurization of the airlock will begin. Mission Control expects the EVA to begin around 12:23 p.m. EST.

1400 GMT (09:00 a.m. EST)

The shuttle Endeavour's crew was awakened at 8:06 a.m. (1306 GMT) to begin preparations for a spacewalk to electrically connect the new P6 solar power tower to the international space station. All 12 batteries in the P6 truss have now been charged and both channels of the huge two-wing array are working normally.

Appropriately enough, the astronauts were awakened by a recording of "Fight On," the University of Southern California's football fight song, for USC graduate Carlos Noriega.

"Good morning, Endeavour, and good morning especially to veteran spacewalker Carlos," astronaut Gerhard Thiele radioed from mission control.

"Good morning, Gerhard, thanks for the wakeup music," Noriega replied. "After the array went out yesterday, we've been in a fantastic mood out here. We're ready to go fight on today."

"We are looking forward to another touchdown," Thiele said.

Noriega and crewmate Joseph Tanner are scheduled to begin their second spacewalk at 12:56 p.m. (1756 GMT). The main goals of today's excursion are to electrically connect the P6 arrays to the station's main bus and to move the station's S-band antenna system from its current location on the Z1 truss to a point atop the P6 array tower.

To complete the necessary electrical connections, station commander William Shepherd, Yuri Gidzenko and Sergei Krikalev will enter the U.S. Unity mode during today's spacewalk to install grounding straps and make internal connections.

Tanner and Noriega, meanwhile, also plan to release latches holding one of the P6 array's two main radiators in place, allowing it to be extended later, and to prepare one of the station's docking ports - PMA-2 - for relocation during the next shuttle visit.

If all goes well, today's spacewalk will end around 7 p.m. (0000 GMT). A mission status briefing is scheduled for 8 p.m. and the crew will begin an eight-hour sleep period at 11:36 p.m. (0436 GMT).

TUESDAY, DECEMBER 5, 2000
0600 GMT (1:00 a.m. EST)

The Endeavour astronauts successfully deployed a second solar array wing on the international space station Monday evening, using a cautious stop-and-start approach to avoid putting too much stress on cables designed to keep the array's two blankets taut. Read our full story.

0249 GMT (9:49 p.m. EST)

The now-deployed port wing is now completely tensioned. Mission Control reports the structure is fully taut. The starboard wing deployed last night, however, remains slack. Engineers are still debating what to do with that wing.

0246 GMT (9:46 p.m. EST)

WING DEPLOYED! The port solar array wing has been fully extended after a lengthy but successful deployment tonight by the crew of space shuttle Endeavour.

The international space station's power-generating solar wings have been spread 240 feet tip-to-tip, increasing the outpost's available power nearly five-fold.

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

Both stuck solar array panels have popped apart. Now the wing will be fully extended and locked into place.

0232 GMT (9:32 p.m. EST)

The solar array wing has been retracted a very slight amount. It will be reextended momentarily in an effort to pop apart one stuck panel on each of the two solar array blankets. The blankets contain 84 panels each, of which 82 are populated with power-generating solar cells.

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

Engineers believe thermal warming and a slight retraction of the solar array wing and subsequent extension will release to the two stuck panels, which is keeping the 110-foot wing from being fully deployed.

0204 GMT (9:04 p.m. EST)

The is one sticking solar array panel on each blanket. Not wanting to stress the blankets, controllers are going to wait and let them warm up.

0147 GMT (8:47 p.m. EST)

The last section-and-a-half of the 31.5-segment of the mast is about to be deployed. The blankets will then be tensioned and latched into place.

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

Endeavour's astronauts have slowly resumed the wing extension. It is believed that the remaining panels were sticking because they have been packaged up for launch for the past nine months.

0130 GMT (8:30 p.m. EST)

Deployment has stopped while three of the remaining panels are examined on the blanket. The panels appear to be sticking together. There are some 84 panels on each solar array blanket.

0124 GMT (8:24 p.m. EST)

The deployment is going much faster than officials had anticipated with 28 of 31.5 segements already extended.

0118 GMT (8:18 p.m. EST)

Ground controllers report the partially deployed port solar array is already generating about 4 amps worth of power. The 110-foot extension continues with the wing remaining steady and taut.

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

Mission Control reports two of the 31-and-a-half segments of the solar array wing mast have been deployed. The operation is going smoothly, officials report.

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

Deployment of the port solar arry wing has begun with a command issued by Endeavour's skipper, Brent Jett. Unlike last night's deployment of the starboard wing that took less than 14 minutes, tonight's extension is expected to take at least an hour. Deployment of the 110-foot long mast, which acts as the wing's backbone, will be stopped at points throughout the extension to allow any motion in the structure to damp out and ensure tension in the two solar array blankets remains tight.

0027 GMT (7:27 p.m. EST)

Following lengthy engineering discussions to ensure the repeated starting and stopping of the solar array mast during deployment tonight would not create any new problems, NASA is finally given its final "go" for the port wing to be unfurled. That deployment could begin very shortly.

MONDAY, DECEMBER 4, 2000
2314 GMT (6:14 p.m. EST)

Mission Control has decided to again delayed deployment of the port solar array wing of the new P6 truss structure. The astronauts were told the ground controllers had a few issues to sort out before the deployment could begin. The operation to extend the 110-foot wing will slip at least one orbit, or 90 minutes, beyond the targeted 6:23 p.m. EST start time.

2200 GMT (5:00 p.m. EST)

The Endeavour astronauts were cleared today to unfurl a second solar array on the international space station, using a stop-and-start approach to avoid stressing tension cables designed to keep the array blankets taut. Read our full story for a look ahead to tonight's deployment.

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

Engineers are still reviewing data from last night's deployment of the starboard solar array wing. As a result, NASA has pushed back the possible deployment of the port wing to no sooner than 6:23 p.m. EST (2323 GMT) today, one orbit later than had been previously targeted.

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

NASA managers have approved a plan to attempt deployment of a second solar wing on the international space station this afternoon, pausing the wing's extension periodically to ensure its solar blankets maintain the proper tension.

The starboard wing of the P6 solar array was deployed Sunday evening after a series of false starts. When the 115-foot wing unfurled, however, one of its two delicate solar blankets was not as taut as expected and NASA managers decided to hold off deploying the port wing to give engineers time to assess the issue.

The concern was that whatever caused the loss of tension in the P6 array's starboard wing could be repeated during deployment of the port wing. During the starboard wing's extension, blanket panels could be seen rippling back and forth along the long axis of the wing, bunching up and suddenly popping free as the wing's mast drew the blankets out of their storage boxes. The deployment was more dynamic than engineers expected and it may have contributed to the tensioning problem.

Early today, NASA's mission management team approved a plan to extend the port wing in deliberate steps to make sure the tensioning system in that wing is not over stressed.

The Endeavour astronauts were awakened at 9:30 a.m. (1430 GMT) to begin their fifth day in space. Before flight controllers could explain the MMT's plan, commander Brent Jett chimed in with his own suggestions about how they might tighten up the port wing and go about deploying the second.

"The more we look at that left blanket box on the starboard array, the tensioning cables, they don't really appear to be broken, it looks like they might be off track or have jumped off the mechanism," he said. "We were thinking about maybe another way to tension the arrays using PRDs (payload retention devices) to tension it and a long duration tether to secure it.

"The other thing we were thinking about, and I'm sure you are as well, is to deploy the other array, maybe doing it manually and letting the EVA guys control the rate. You guys might have a lot more insight than we do, but we just thought we'd let you know what we're thinking about up here in case you hadn't considered those already."

"Thanks, Brent, for sharing your ideas with us," replied astronaut Gerhard Thiele in mission control. "We were thinking along the same tracks. Currently, we are planning to deploy the second array today with pause points. However, the orbit one shift will come back with more info on that."

Engineers have tentatively scheduled an attempt to deploy the port array for 4:41 p.m. What, if anything, might be done to increase tension on the port array's loose blanket is not yet known.

The astronauts will discuss all of this during interviews with three television networks starting at 3:16 p.m. The crew is scheduled to take the rest of the afternoon off.

MONDAY, DECEMBER 4, 2000
0550 GMT (12:50 a.m. EST)

Endeavour's five astronauts are now asleep after a very busy day in orbit that saw the 35,000 pound P6 power truss attached to the international space station, increasing the orbital complex's mass to 97 tons. Spacewalking astronauts Joe Tanner and Carlos Noriega bolted the truss into place and connected nine command, data and power cables between P6 and the rest of the station.

The spacewalkers moved on to release launch restraints holding the two solar array assemblies into place and readied the $600 million station element to be activated.

After several nagging glitches were resolved, the starboard solar array wing was extended to its full length of 110 feet. But ground controllers quickly noted that one of the two solar array blankets that make up the wing was not taut. Tension struts in the blanket were clearly not tight and slack was noted in the structure in television downlinked by the shuttle.

NASA officials opted to cancel plans to deploy the second wing on Sunday night, instead deciding to allow engineers more time to study the tension issue. Deployment of the port wing could occur as early as Monday afternoon.

Initial data showed the starboard wing was generating adequate power to recharge onboard batteries despite the slack blanket.

The P6 solar arrays are designed to quintuple the available power on the station.

Mission Control told Endeavour's crew they will extend their sleep period an extra hour tonight. The wakeup call is now expected at 9:36 a.m. EST (1436 GMT).

0421 GMT (11:21 p.m. EST)

The Photovoltaic Radiator has been fully extended from the international space station's new P6 truss segment. Deployment took six minutes and six seconds to complete. The radiator will be used to dissipate heat into space from the power-generating P6 module.

This is the final major task for Endeavour's five-man crew tonight. They are scheduled to begin an eight-hour sleep period at 12:36 a.m. EST. Monday had been slated to be a relatively light work day for the astronauts, but deployment of the second solar array wing may be ordered if engineers complete analysis of the slack tension noted on one of the blankets in the first wing extended tonight.

0415 GMT (11:15 p.m. EST)

The radiator is part of the Integrated Equipment Assembly of the P6 truss structure.

0413 GMT (11:13 p.m. EST)

The 44-foot Photovoltaic Radiator is now deploying like an accordion.

0410 GMT (11:10 p.m. EST)

The first step in the deployment sequence is beginning for the Photovoltaic Radiator on the P6 solar array truss mounted the international space station just hours ago. The Endeavour astronauts have powered up the system for deployment of the radiator, which is expected very soon.

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

NASA has revised the duration of today's spacewalk to 7 hours and 33 minutes, one minute shorter than previously announced.

0355 GMT (10:55 p.m. EST)

A news conference with NASA officials just wrapped up and lead STS-97 flight director Bill Reeves says the starboard solar array wing is definitely deployed to its full length. However, the tension in one of the two blankets that make up the wing is a little slack. The loose tension is not considered a major problem but officials opted not to deploy the port wing tonight while further engineering analysis is underway.

The second wing could be unfurled as early as Monday pending NASA managers' decision.

Meanwhile, deployment of the PV radiator is still upcoming this evening. The cooling structure has not yet been commanded to deploy by the shuttle crew.

0248 GMT (9:48 p.m. EST)

The decision has been made to postpone deployment of the second of two solar array wings of the international space station's newly-installed P6 truss structure for tonight. Deployment won't be performed until at least sometime Monday.

Officials have decided, however, to go ahead and deploy the photovoltaic radiator on the truss tonight as planned. That will be upcoming in about 45 minutes.

The starboard wing extended earlier tonight is generating sufficient power to charge batteries in the P6 truss. But it is thought that the tension in the 110-foot wing is not completely tight. Engineers will continue to review the situation overnight before allowing the second wing to be unfurled.

0237 GMT (9:37 p.m. EST)

NASA officials continue discussions whether to deploy the port solar array wing tonight while engineering analysis goes on with the two tensioning cables on the deployed starboard wing that appear slack.

0222 GMT (9:22 p.m. EST)

The latches were commanded open on the port array box and the cycling effort appears to have worked. All the pins are open and the wing is now free to deployed, possibly this evening.

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

The restraint latches on the port solar array wing have been commanded closed in an effort to later drive them open to free the stuck pin.

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

Flight controllers have decided the starboard solar array wing tensioning is acceptable for now because power-generation is within limits for battery recharging, and the astronauts should not help in troubleshooting of a restraint pin holding the port wing into its launch box.

0209 GMT (9:09 p.m. EST)

Today's spacewalk officially concluded at 9:09 p.m. EST (0209 GMT) with the start of airlock repressurization. This 11th spacewalk devoted to international space station assembly lasted a total duration of seven hours and 34 minutes. The spacewalk was the 94th in the history of the U.S. space program, the 55th from a space shuttle and first of three planned on this mission of STS-97. It was the third EVA for Joe Tanner and the first for Carlos Noriega.

0202 GMT (9:02 p.m. EST)

Endeavour's airlock hatch has been closed and locked by the spacewalkers. Pressurization of the airlock will begin shortly, officially ending today's spacewalk. Mission Control has told the astronauts they may want to prepare an eye wash to spacewalker Carlos Noriega who complained of irritation.

0157 GMT (8:57 p.m. EST)

Commander Brent Jett reports he believes one of the solar array blankets may not have deployed entirely with one small section, or panel, still folded. The deployed wing has two blankets, with each blanket comprised of 84 panels.

0152 GMT (8:52 p.m. EST)

Mission Control just told the spacewalkers it is time to wrap up their excursion for the day.

Meanwhile, controllers are carefully looking at two tensioning cables on one of the deployed solar array blankets that appear slack.

0144 GMT (8:44 p.m. EST)

A decision on whether the crew should send commands to add more tension to the starboard array wing has not been made. Also, the issue with a restraint pin holding the port solar array box is still being discussed. It is unclear if one of the pins holding that box closed has been released. So the second half of the P6 solar arrays won't be extended until the pin problem is cleared up.

0138 GMT (8:38 p.m. EST)

Controllers are looking to see if more tension needs to be applied to the solar array wing that has been deployed.

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

The first of two solar array wings for the international space station has been fully extended. The wing has two solar array blankets, each with 84 panels, of which 82 are populated with solar cells. Each blanket contains 200 solar cells.

0135 GMT (8:35 p.m. EST)

Spacewalker Carlos Noriega is returning to the airlock now. He reported minor eye irritation and will purge his helmet.

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

About two-thirds of the starboard solar arrays have been extended.

0128 GMT (8:28 p.m. EST)

Deployment of one side of the power-generating solar arrays of the P6 truss continues without incident.

0126 GMT (8:26 p.m. EST)

The telescoping mast structure for the solar arrays is the same design used by the antenna of the Shuttle Radar Topography Mission back in February.

0123 GMT (8:23 p.m. EST)

DEPLOYMENT BEGINS. The right side solar arrays of the P6 structure are now unfurling. The process will take about 15 minutes to complete, with the wings stretching nearly 110 feet in length. There are two array blankets being extended with an extendable mast serving as a backbone between the two.

The left side arrays will be deployed later.

0122 GMT (8:22 p.m. EST)

Deployment of the starboard solar array of the P6 truss is about to begin in the next few moments

0117 GMT (8:17 p.m. EST)

Space station ground controllers report all the pins on the port arrays are indeed open. The "go" for deployment is still to come, however.

0108 GMT (8:08 p.m. EST)

To recap, deployment of the two solar arrays on the port side of the P6 truss is on hold while ground controllers verify the position of one restraint pin keeping the right solar blanket box closed. The pin must be open for deployment but there is the indicate the pin may be closed.

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

Today's spacewalk now passing 6 hours and 30 minutes in duration.

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

Carlos Noriega is moving back into Endeavour's airlock to hook his spacesuit back to shuttle-supplied consumables because his oxygen supplies is getting a little low.

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

Mission Control had given a "go" for deployment of the port arrays. However, that "go" was taken back while a further review is made to confirm that the No. 3 pin has been opened on the starboard array box on the port side of P6. The pins hold the solar array blankets folded up in their compact boxes.

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

All the restraint pins on the two port solar array boxes have been verified open. This sets the stage for the two solar array wings on port side with the extendable backbone boom between them.

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

NASA reports the latches on the starboard solar array box of the port side of P6 are now opening.

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

The spacewalkers are trying to look to verify the solar array latch pins have fully retracted on the port box.

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

Finally success! The latest attempt to command the port solar array box latches has worked. So deployment of the arrays could begin shortly.

0035 GMT (7:35 p.m. EST)

Another attempt to release the port side solar array latches has been unsuccessful. The commanding was halted and ground controllers report they are puzzled what is causing the problem.

0029 GMT (7:29 p.m. EST)

Mission Control just informed the shuttle crew that they spacewalk will likely be extended an additional hour to a duration of about 7.5-hours while the ground continues to sort out the solar array latch commanding problem. The walk has already lasted nearly six hours.

0027 GMT (7:27 p.m. EST)

The space station flight controllers in Houston are planning to send an automatic command from the ground to release the latches holding the solar arrays folded up in their boxes. Should that fail, then the spacewalkers could manually open the latches.

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

Flight controllers plan to restart the software in hopes of correcting the commanding problem experienced tonight with the new solar arrays. The next attempt to unlock the arrays for deployment won't come for another half-hour or so.

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

The spacewalkers have been told to start cleaning up the payload bay, putting away their tools and equipment and head back to Endeavour's airlock. Once in the airlock, they will switch their suits back to shuttle-supplied consumables. They won't repressurize the airlock since there is a chance the spacewalkers will need to climb back up the truss and manually deploy the arrays. This spacewalk has lasted nearly six hours.

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

Flight controllers have seen the same temporary dropout in the commanding path for routing of the power from the arrays to P6 truss electronics on the starboard side. So the deployment of the arrays on both port and starboard sides is now on hold. Controllers believe this is a software problem.

0008 GMT (7:08 p.m. EST)

A new game plan is being developed to deploy the starboard solar array first and while the spacewalkers are still outside in the payload bay. The original plan called for the port array to be unfurled to first and the astronauts to return to the airlock before any deployment was performed. But the shuttle-station stack has been maneuvered to a special position that will allow good attitude for deployment while protecting the spacewalkers.

0003 GMT (7:03 p.m. EST)

Mission Control is discussing the possibility of deploying the starboard side solar array first instead of the port side, which is the original plan. This will allow engineers more time to examine the routing issue that has come up.

2359 GMT (6:59 p.m. EST)

Flight controllers are looking at an issue with devices that route power from arrays to the P6 truss electronics. A NASA spokesman reports this is not expected to a big problem, but something the ground is looking at.

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

International space station flight director Jeff Hanley reports the power channels on the P6 truss have checked out fine and the station control team are "go" for the port solar array wing to be deployed. That extension will occur shortly once the spacewalkers return to the airlock.

Also, both solar array blanket boxes have been configured for deployment.

The spacewalkers will stay in the airlock for safety sake. However, they will be prepared to climb back up the P6 truss to manually deploy the arrays if a problem arises.

2335 GMT (6:35 p.m. EST)

Now five hours into today's spacewalk. Tanner and Noriega will be headed back into Endeavour's airlock shortly after cleaning up the payload bay and putting away their tools. Once in the airlock, commander Brent Jett will sent the crucial commands to deploy the power-generating solar arrays for the international space station.

2329 GMT (6:29 p.m. EST)

Noriega has completed releasing the launch restraints holding the PV radiator. The radiator will be extended later tonight after the solar arrays are unfurled.

Meanwhile, Tanner has deployed the port side solar array boxes.

2326 GMT (6:26 p.m. EST)

The spacewalk winding down, Mission Control has told the crew to begin maneuvering the shuttle and station stack to the solar array deployment attitude. The deployment is at least a half-hour away.

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

Spacewalker Joe Tanner reports three of the latches have engaged on the port beta gimbal assembly, which is sufficient for solar array deployment on that side. The starboard side was locked into place a little earlier by Noriega.

2308 GMT (6:08 p.m. EST)

Noriega has released three bolts on the end of the telescoping boom canister to allow the mast to be deployed. The boom forms the backbone of the solar arrays when extended.

He will now move to release six "cinches" restraints holding the photovoltaic radiator into its stowed position. The radiator is slated for deployment later tonight.

2259 GMT (5:59 p.m. EST)

Carlos Noriega is working to rotate the two 15-foot long boxes containing the solar arrays from their stowed launch position the deploy position. Once rotated, a locking arm holds the boxes into place.

2255 GMT (5:55 p.m. EST)

Spacewalker Joe Tanner is preparing to deploy the port beta gimbal assembly.

2239 GMT (5:39 p.m. EST)

Mission Control has told the spacewalkers to forego any further attempt to engage the fourth latch on the starboard beta gimbal assembly. The three latches that are engaged are enough to support the assembly for deployment of solar arrays.

The spacewalkers are now pressing ahead to deploy the port assembly.

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

Now four hours into today's spacewalk.

2233 GMT (5:33 p.m. EST)

The third of four latches has engaged on the starboard assembly, the minimum needed for deploying the solar arrays. They will continue to try to get the fourth latch to engage, though.

2228 GMT (5:28 p.m. EST)

Using a ratchet strap, the spacewalkers are applying extra force to get the starboard beta gimbal assembly to latch into its deployed positioned. Just two of the four latches have engaged.

Meanwhile, Mission Control has told the crew not to attempt to deploy the port assembly until the starboard is latched into place.

2222 GMT (5:22 p.m. EST)

Noriega is releasing the pip pin launch restraints holding the two solar array boxes on the starboard side.

2208 GMT (5:08 p.m. EST)

Only two of the four latches have engaged on the starboard beta gimbal assembly. The spacewalkers are getting a tool to pull the assembly to get at least a third latch to engage, which is required before solar array deployment. The tool may be used again to aid in deployment of the port assembly.

The beta gimbal assemblies, measuring 8 by 8 by 2 feet, consist of the mast canister that holds the telescoping boom on which the arrays are connected, the Bearing, Motor and Roll Ring module uses to rotate the array to track the sun, the Electronic Control Unit used to control the gimbal's motor and mast rotation and the Sequential Shunt Unit needed to regulate the wing output voltage.

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

Tanner is now releasing the launch restraint to free the two port solar array boxes. The boxes (20 inches thick and 15 feet in length) are currently folded down, but will soon be extended upward 90 degrees to form a T-shape in preparation to unfurl the solar arrays.

2203 GMT (5:03 p.m. EST)

Noriega has gone off to retrieve a tool that will be used to latch the gimbal assemblies into place.

2200 GMT (5:00 p.m. EST)

The spacewalkers have taken a moment today to reattach some multi-layer thermal insulation blankets on the beta gimbal assemblies of the P6 truss. The insulation because loose during launch and the velco needed to be pushed down.

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

Once the port beta gimbal launch restraints are released, the assembly will be pushed outward to its deployed position. This assemblies contain the folded solar arrays tucked away in compact boxes. The spacewalkers will shortly rotate the boxes 90 degrees from the launch position to a deploy configuration. You can watch a video clip from NASA animation showing this operation.

2145 GMT (4:45 p.m. EST)

Noriega is now pushing the starboard beta gimbal outward to its deployed position.

2143 GMT (4:43 p.m. EST)

Spacewalker Noriega has released two bolts holding the starboard solar array beta gimbal. This will allow the assembly to swing outward from its stowed position on the P6 truss. Tanner will be doing this same task on the port assembly.

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

Now three hours into today's spacewalk.

2129 GMT (4:29 p.m. EST)

Noriega has climbed to the top of the P6 truss where Tanner has been worked for about the last hour. His helmet-mounted video camera provided a stunning view of Noriega's near-50-foot journey.

The spacewalkers are releasing bolts that are holding the solar arrays against the side of the P6 structure in advance of deploying the wings about two hours from now.

2119 GMT (4:19 p.m. EST)

The nine power, command and data umbilicals from the Z1 framework to the P6 truss have been mated by spacewalker Carlos Noriega. He will not join fellow spacewalker Joe Tanner near the top of the P6 tower release the launch restraints holding the starboard solar array beta gimbal assembly.

2117 GMT (4:17 p.m. EST)

Noriega has completed eight of the nine cable connections.

2106 GMT (4:06 p.m. EST)

Working near the top of the P6 truss some 90 feet above the payload bay of space shuttle Endeavour, spacewalker Joe Tanner has released the launch restraints holding the starboard solar array blanket box. He will release the port side box next. There are eight 5/8ths-inch bolts on each box -- two on the nadir and six on the zenith ends of the boxes -- that Tanner is releasing.

2100 GMT (4:00 p.m. EST)

The umbilical connections by spacewalker Carlos Noriega continue. He has not reported any significant trouble with this chore.

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

Noriega is in the process of hooking up the nine cables between the newly-installed P6 truss and the rest of the international space station.

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

Now two hours into today's spacewalk. Noriega is getting into position on the end of the shuttle's robot arm to be maneuvered by arm operator Mike Bloomfield from inside Endeavour. He will connecting nine power, command and data umbilicals from the Z1 framework to the forward face of the P6 structure. The cables provide power to the Orbital Replacement Units. As Bloomfield controls the arm, Marc Garneau has moved into his role as the spacewalk choreographer to oversee the EVA activities.

Upcoming for spacewalker Tanner will be the release of launch restraints holding the two solar array blanket boxes into place against the side of the P6 truss.

2019 GMT (3:19 p.m. EST)

Today's spacewalk continues to proceed extremely well. Spacewalker Noriega is about to retrieve the tools he will need to connecting various electrical cables between P6 and the Z1 truss. The cables will allow power to be routed to P6.

Also, the shuttle's robot arm has ungrappled the P6 truss now that it is part of the international space station. The arm will be used to move the spacewalkers around for the rest of the day.

2009 GMT (3:09 p.m. EST)

All four corner bolts have been tightened by the spacewalkers, making the power-generating P6 solar array truss a permanent piece of the international space station. This 17-ton structure increases the total mass of the station to 97 tons.

2001 GMT (3:01 p.m. EST)

Along with installing the four bolts, the spacewalkers will be attaching grounding straps and umbilical cables between P6 and the Z1 trusses as the day goes along.

1951 GMT (2:51 p.m. EST)

Two of the four bolts have been fully tightened. The other two bolts (diagonal from each other) are in work by spacewalkers Tanner and Noriega.

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

The crew of Endeavour are making it look easy in space today. The giant P6 truss has been attached to the international space station, and the spacewalkers are now bolting the structure into place.

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

Noriega has driven the capture claw closed to solidly mate the P6 truss to the station. One bolt in each of the four corners of the truss will now be installed by the spacewalkers.

The P6 solar array segment is made up of three elements: The two photovoltaic solar wings themselves; an integrated electronics assembly housing batteries and other critical gear; and a truss section called the "long spacer" that includes thermal control equipment.

The P6 truss also houses a deployable radiator. Ammonia coolant lines from the U.S. laboratory module ultimately will be connected through the Z1 truss to the radiator to dissipate heat generated by the lab's electronic gear.

This 17-ton package is the heaviest and largest element yet delivered to the station by a space shuttle.

1932 GMT (2:32 p.m. EST)

The P6 truss has been berthed to the international space station. The spacewalkers will now engage a large mechanical claw to physically hold the 49-foot tall structure to the Z1 truss of the station. Four bolts will be driven later to permanently keep the two pieces firmly docked together.

1929 GMT (2:29 p.m. EST)

The spacewalkers are providing visual guidance cues to robot arm operator Marc Garneau as he slowly maneuvers the truss. About 21 inches to go before attachment.

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

Endeavour's robot arm is now moving the P6 truss towards mating to the international space station.

There is a claw-like device on the Z1 truss of the space station that is designed to capture a bar on the bottom of the P6 truss. That will initially connect the truss to the station with four bolts to be added later by the spacewalkers this afternoon.

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

Tanner and Noriega report they like the current alignment of the P6 solar array truss as it is suspended about three feet about the capture plate. Installation is upcoming shortly.

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

The spacewalkers are getting themselves set up to prepare for the P6 installation.

1858 GMT (1:58 p.m. EST)

Tanner and Noriega are making their way to toolboxes mounted to the Z1 truss of the international space station to retrieve equipment they will need for today's spacewalk.

1850 GMT (1:50 p.m. EST)

During this spacewalk Joe Tanner can be distinguished as his spacesuit has red stripes on the legs. Carlos Noriega's is solid white.

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

Today's spacewalk is the 94th in the history of the U.S. space program and 55th from a space shuttle. It also marks the 11th spacewalk dedicated to assembly of the international space station. For Joe Tanner, this is his third spacewalk after performing two EVAs to service the Hubble Space Telescope in 1997. Carlos Noriega is making is first spacewalk today.

1839 GMT (1:39 p.m. EST)

Astronauts Joe Tanner and Carlos Noriega switched their spacesuits from shuttle-provided powered to internal batteries at 1:35 p.m. EST, signalling the official start of today's planned 6.5-hour space station construction spacewalk.

The two men will float outside the shuttle's airlock hatch in the next few minutes and head up to the Z1 framework truss on the Unity node of the international space station where the P6 solar array truss is to be mounted this afternoon. From that vantage point, they will be able to provide a first-hand view of the capture plate and assist robot arm operator Marc Garneau to align the structure for its attachment. Once lowered into place, the spacewalkers will bolt the truss to the station.

This is the first of three spacewalks planned on this shuttle mission -- with the others to follow on Tuesday and Thursday. The subsequent excursions will be to wire the solar arrays to the space station's electrical system and to install instrumentation to measure the orbiting complex's electrical environment, respectively.

1831 GMT (1:31 p.m. EST)

The spacewalkers are preparing to open the airlock's outer hatch. The spacewalk will officially begin when the two astronauts switch their suits to battery power.

1824 GMT (1:24 p.m. EST)

The airlock pressure has dropped to 5 psi where it is holding for a leak check. Once that check is conducted, the pressure will be reduced to vacuum so the spacewalkers can open the airlock hatch and begin today's excursion.

1818 GMT (1:18 p.m. EST)

Commander Brent Jett reports Endeavour's airlock hatch has been closed and locked. The spacewalkers have also completed their oxygen prebreathing, so the 15-minute process to depressurize the airlock is starting in advance of beginning the EVA.

1807 GMT (1:07 p.m. EST)

The spacewalkers have another 10 minutes left to go in their pure oxygen breathing exercise. After that they will begin to depressurize Endeavour's airlock. The EVA is expected to start at half-past this hour.

1740 GMT (12:40 p.m. EST)

Spacewalkers Joe Tanner and Carlos Noriega have donned their suits and are now breathing pure oxygen in advance of starting today's adventure outside the shuttle. The spacewalk is slated to get underway just about on-time, Mission Control believes, at about 1:30 p.m. EST.

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

The P6 Integrated Truss Segment is now in its so-called premate position about three feet above its attachment point on the international space station. The truss, riding on the end of the shuttle's robot arm, will hold in this position until after the spacewalk begins in about two hours.

Activities for the spacewalk are continuing aboard Endeavour with the Tanner and Noriega having donned their liquid-cooled undergarments. They are now in the process of testing the voice and data communications from their EMU spacesuits before pressing ahead to suit up.

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

Canadian astronaut Marc Garneau has resumed the job to maneuver the giant P6 solar array truss structure -- extending 49 feet in length and 35,000 pounds in mass -- from its overnight parking position on the end of the shuttle's robot arm about 10 feet above Endeavour's payload bay. The P6 is being hoisted to a point just three feet above its attachment port on the international space station's Z1 framework truss. The Z1, as you may remember, was added to the complex during the October shuttle flight.

Meanwhile, astronauts Joe Tanner and Carlos Noriega are in the middeck of Endeavour preparing for their spacewalk later today. The two will be suiting up and later enter the shuttle's airlock for the scheduled start of the EVA expected around 1:30 p.m. EST (1830 GMT). However, they are running a bit ahead of the timeline so the spacewalk could begin early.

The spacewalkers' first task will be to climb up to the Z1 truss to assist Garneau with visual cues for the actual mounting of the P6 structure.

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

The move of the P6 Truss to the "pre-mate position" has been brought forward to about 10:30 a.m. EST at the request of Russian flight controllers. Moving the truss earlier will provide better power margins for the Zvezda service module.

1340 GMT (08:40 a.m. EST)

The Endeavour astronauts were awakened at 1336 GMT (08:36 a.m. EST) today to begin preparations for a complex spacewalk this afternoon to attach a $600 million set of solar arrays to the international space station.

Joseph Tanner and Carlos Noriega are scheduled to officially begin the spacewalk at 1831 GMT (01:31 p.m. EST), but the excursion could begin up to 45 minutes early if the astronauts complete preparations in time.

The astronauts were awakened by a recording of "Sunshine of Your Love" radioed up from mission control. "Good morning, Endeavour, and especially good morning for Carlos and Joe T," called astronaut Gerhard Thiele from the control center.

"Good morning, Houston, and thanks for the tune," replied Tanner. "And for the thousands of people who have worked for years to see the sun shine on these arrays, you won't find five guys more eager to make that dream come true today."

This will be the 55th spacewalk in shuttle history - the 94th by U.S. astronauts - and the 11th devoted to space station outfitting and assembly. During five previous shuttle missions, station EVA crews logged 69 hours and 35 minutes of station assembly time during 10 spacewalks, or EVAs. During Endeavour's mission, Tanner and Noriega plan three EVAs, each one lasting six to six-and-a-half hours.

The Endeavour astronauts docked with the space station Friday. Canadian astronaut Mark Garneau used the shuttle's robot arm to pluck the 17.5-ton P6 array out of the cargo bay and into an overnight "thermal park" position to keep it from getting too hot or too cold.

The astronauts also briefly opened a hatch leading into the PMA-3 docking port to leave computer gear, fresh coffee, vice grip pliers and other supplies for the station's three-man crew. Station commander William Shepherd and his crewmates retrieved the welcome supplies early today and then exited PMA-3 and the U.S. Unity module, sealing hatches behind them.

The two crews will not be able to greet each other in the flesh until late this week, after all three spacewalks are complete. That's because the air pressure in the shuttle is being maintained at 10.2 psi - about 5 psi less than the station's - to help Noriega and Tanner avoid the bends when using their 5-psi spacesuits.

We will provide detailed play-by-play coverage of today's spacewalk, along with a detailed wrapup story after a post-EVA news conference at the Johnson Space Center.

Read our earlier status center coverage.