History > 2007 > USA > Space (III)

ISS016-E-006573 (28 Oct. 2007) ---

Space Shuttle Discovery,

docked to the Pressurized Mating Adapter (PMA-2)

on the International Space Station,

is featured in this image photographed by a spacewalker

during the second session of extravehicular activity (EVA)

for the STS-120 mission.

NASA

http://www.nasa.gov/images/content/195067main_iss016e006573_hires.jpg

http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts120/multimedia/fd6/fd6_gallery.html

S120-E-007003 (28 Oct. 2007) ---

Astronaut Daniel Tani, Expedition 16 flight engineer,

participates in the second of five scheduled sessions of extravehicular activity (EVA)

as construction continues on the International Space Station.

During the 6-hour, 33-minute spacewalk

Tani and astronaut Scott Parazynski (out of frame), STS-120 mission specialist,

worked in tandem to disconnect cables from the P6 truss,

allowing it to be removed from the Z1 truss.

Tani also visually inspected

the station's starboard Solar Alpha Rotary Joint (SARJ)

and gathered samples of "shavings"

he found under the joint's multi-layer insulation covers.

Also the spacewalkers outfitted the Harmony module,

mated the power and data grapple fixture

and reconfigured connectors on the starboard 1 (S1) truss

that will allow the radiator on S1 to be deployed from the ground later.

NASA

http://www.nasa.gov/images/content/195079main_s120e007003_hires.jpg
http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts120/multimedia/fd6/fd6_gallery.html

ISS016-E-007421 (30 Oct. 2007) ---

Astronaut Scott Parazynski, STS-120 mission specialist,

participates in the third scheduled session of extravehicular activity (EVA)

as construction continues on the International Space Station.

During the 7-hour, 8-minute spacewalk

Parazynski and astronaut Doug Wheelock (out of frame), mission specialist,

installed the P6 truss segment with its set of solar arrays to its permanent home,

installed a spare main bus switching unit on a stowage platform,

and performed a few get-ahead tasks.

Also, Parazynski inspected the port Solar Alpha Rotary Joint (SARJ)

to gather comparison data for the starboard rotary joint.

Various components of the station are visible

in the reflections in Parazynski's helmet visor.

NASA

http://www.nasa.gov/images/content/195460main_iss016e007421_hires.jpg
http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts120/multimedia/fd8/fd8_gallery.html

Shuttle Astronauts Greeted

in Houston

November 8, 2007
Filed at 10:18 p.m. ET
By THE ASSOCIATED PRESS
The New York Times

HOUSTON (AP) -- A day after ending a grueling and historic 15-day mission, the seven astronauts of the space shuttle Discovery arrived in Houston to a cheering crowd of relatives, friends and colleagues.

''It's just wonderful to be here, finally, face to face with you again,'' said Commander Pamela Melroy, who became only the second woman to land a shuttle and whose leadership coincided with the first woman-led crew of the international space station.

The shuttle, which landed Wednesday in Florida after its first coast-to-coast re-entry since the Columbia disaster five years ago, also brought Clay Anderson back to Earth after 152 days aboard the space station.

Anderson had left on his father's birthday and returned on his own 15th wedding anniversary, the astronaut said after the crew arrived at Houston's Ellington Field.

''You can't write a script that's any better than that,'' he said.

President Bush, in Houston for a fundraiser, took time to shake hands and be photographed with astronauts and their families.

The most dramatic and challenging moments of the mission came on Saturday, when the shuttle crew and the three astronauts aboard the space station teamed up to repair a damaged solar wing.

Using wire cutters, pliers and homemade tools, Scott Parazynski made the repairs in a single unplanned spacewalk. His seven-hour excursion -- one of the most dangerous repairs ever attempted in orbit -- also marked the farthest anyone had ventured from the space station.

Melroy described herself as a bit of a ''terrified mom'' when she sent Parazynski out to repair the array. ''Maybe you heard me squeak: 'Be careful,''' she joked.

''I thought you said, 'Don't break anything,''' responded Parazynski, who described himself as ''verklempt'' when he thanked his family for their support.

The successful repair to the 110-foot solar panel allows the space agency to go ahead with the next flight to the space station in early December. A European space lab will be launched aboard Atlantis.

Shuttle Astronauts Greeted in Houston, NYT, 8.11.2007, http://www.nytimes.com/aponline/us/AP-Space-Shuttle.html

Shuttle Touches Down

After Tough Mission

November 8, 2007
Filed at 3:42 a.m. ET
By THE ASSOCIATED PRESS
The New York Times

CAPE CANAVERAL, Fla. (AP) -- Space shuttle Discovery's 15-day mission already seemed a bit like a dream to commander Pamela Melroy just hours after the crew's safe landing.

She recalled Wednesday how she and her crewmates cheered on the way home while admiring their makeshift patches to a wing on the international space station.

''That's one thing that we'll always look at the station and remember,'' she said. ''So it feels a little more real to us in that way.''

The shuttle touched down on a crisp and bright fall afternoon after safely crossing the continent in the first coast-to-coast re-entry since the Columbia disaster almost five years ago.

The seven shuttle astronauts and three residents of the international space station teamed up during the mission to save the mangled solar wing.

It was one of the most difficult and dangerous repairs ever attempted in orbit, but the future of the space station was riding on it and Scott Parazynski pulled it off in a single spacewalk. The repair allows the space agency to press ahead with the next shuttle flight to the space station in early December.

On its way home, Discovery crossed over Canada's British Columbia and made a diagonal descent over Montana, Wyoming, the Great Plains, the Deep South and, finally, down into Florida. NASA opted for the more populous route to avoid a riskier landing in darkness, and to give the crew some extra rest after such a long and strenuous flight.

Double inspections of the spaceship's wings in orbit confirmed the thermal shielding would hold up to the 3,000-degree heat of atmospheric re-entry. A quick look at the shuttle on the landing strip showed little if any damage.

NASA Administrator Michael Griffin said the flight, from start to finish, demonstrated ''NASA at its very best.'' He described the landing as ''spot on'' and also ''just as pretty as it gets -- if that matters.''

Even before the mission began Oct. 23, the astronauts knew they were in for one of the most challenging and complicated space station construction missions ever.

They had no trouble installing a pressurized compartment named Harmony and moving a girder from one side of the space station to another. They even managed to peek into a clogged joint needed to turn the right-sided set of solar wings.

But the flight took a dramatic turn Oct. 30 when it came time to unfurl the solar wings on the relocated girder on the left side of the space station. The first wing popped out fine, but the second one became snagged in a clump of tangled wires and ripped in two places.

Flight controllers rushed to come up with a repair plan. On Saturday -- just four days after the damage occurred -- Parazynski floated outside with wire cutters, pliers and some homemade tools and fixed the torn wing.

No one had ever ventured so far from the safe confines of the space station before or worked right up against a solar wing coursing with more than 100 volts of electricity and swaying back and forth. Parazynski was propped on the end of a 90-foot extension beam that just barely reached the wing's damaged section.

Parazynski admitted Wednesday night that he had more butterflies than usual before venturing outside that day. The fine print in the procedures sent up from Mission Control read, ''`You may expect some sparkling or sparking in the damaged array,' and I thought, wow, that's pretty exciting. That's more exciting than I bargained for.''

The astronauts gathered samples of the steel grit that was discovered inside the joint and brought them back in a plastic bag. It was one of the first items NASA grabbed following touchdown. By analyzing the shavings, engineers hope to pinpoint the source of the problem and devise a way to replace the grinding parts and clean up the mess, possibly with magnets.

Discovery also brought back a former space station resident, Clayton Anderson. He left the planet in June and spent 152 days in orbit. Wednesday was his 15th wedding anniversary, and he couldn't wait to be reunited with his wife, Susan.

Melroy, meanwhile, became only the second woman to land a space shuttle. Her flight coincided with the first female-led space station crew, and catapulted Melroy and station skipper Peggy Whitson into NASA history books.

------

On the Net:

NASA: http://spaceflight.nasa.gov 

    Shuttle Touches Down After Tough Mission, NYT, 8.11.2007, http://www.nytimes.com/aponline/us/AP-Space-Shuttle.html

Astronauts Prepare for Return Home

November 6, 2007
Filed at 10:54 a.m. ET
By THE ASSOCIATED PRESS
The New York Times

HOUSTON (AP) -- Discovery's astronauts got their spaceship ready for the ride home on Tuesday, wrapping up a 15-day mission that kept the crew far busier than planned.

NASA said the preliminary weather forecast looked good for Wednesday's planned early afternoon touchdown at Kennedy Space Center in Florida.

The landing originally was scheduled before dawn, but commander Pamela Melroy said she asked Mission Control to switch it to daylight to make it easier on herself and her crew.

The schedule change also allowed the seven astronauts to shift their sleep time later instead of earlier, she said in an interview with The Associated Press.

This 15-day mission is longer than most -- and more stressful, too, with the astronauts required to carry out repairs to a torn solar energy panel at the space station.

Melroy said she was ''extremely concerned'' when spacewalker Scott Parazynski went outside to work on the ripped wing Saturday.

''You may have heard me at one point kind of squeak out 'Be careful' as I saw the solar array coming toward him,'' she told the AP. ''But I got more comfortable because I was watching him very closely ... and he was using good body position and hand techniques.''

She also took comfort in the fact that another astronaut, Douglas Wheelock, was watching over everything from the base of the solar wing.

Parazynski said that he barely managed to reach the wing's snagged wires and cut them.

''Another foot beyond that and I don't think we could have reached it,'' he said. ''If it had been any farther away, it would have been a Plan B or C or D. I don't know what it would have been.''

After leaving the space station on Monday, the astronauts used a laser- and camera-tipped boom to hunt for possible micrometeorite damage to the shuttle's wing and nose that might have occurred during the 11 days the shuttle was docked to the orbiting outpost.

NASA was finishing up its analysis of the latest laser data and expected to let the astronauts know later Tuesday if they are cleared for landing.

Because of the schedule switch to a daytime landing, Discovery will make the first coast-to-coast re-entry since Columbia disintegrated over Texas in 2003.

Discovery's original landing plan called for the ship to glide up from the southwest over Central America and the Caribbean before landing in Florida. But now the shuttle will descend over the Pacific Northwest and all the way across the country into Florida.

The astronauts woke up Tuesday morning to Deep Purple's ''Space Trucking,'' played for astronaut Clayton Anderson, who's headed home after a five-month stay on the space station.

''You know they say all great things have to come to an end, and I'm really sorry that I have to agree with that for now, but I had an awesome ride with several awesome crews,'' Anderson said. ''I miss my family and I miss my friends and I'm looking forward to being back on the ground.''

Anderson said he's looking forward to ice-cold drinks and ice cream, which are unavailable on the space station.

Shuttle Atlantis, meanwhile, is being prepped for launch as early as Dec. 6. It is set to deliver a new European laboratory called Columbus to the space station.

------

On the Net:

NASA: http://spaceflight.nasa.gov

    Astronauts Prepare for Return Home, NYT, 6.11.2007, http://www.nytimes.com/aponline/us/AP-Space-Shuttle.html

Shuttle Undocks From Station

November 5, 2007
Filed at 8:29 a.m. ET
By THE ASSOCIATED PRESS
The New York Times

HOUSTON (AP) -- After a week and a half of intense and unprecedented work, the astronauts aboard shuttle Discovery undocked from the international space station on Monday to begin their two-day journey home.

''Thank you guys for the module and all your help,'' space station commander Peggy Whitson said as Discovery pulled away from the orbiting outpost.

Discovery's crew arrived at the station on Oct. 25 and quickly accomplished the ambitious tasks of moving a massive solar power tower and installing the module, a school bus-sized compartment that will serve as a docking port for future laboratories.

But their toughest assignment emerged when one of the newly installed tower's wings ripped in two places as it was being unfurled.

Fearing the damage could worsen and the wing could be ruined, NASA sent a spacewalking astronaut far from the safety of the station to make emergency repairs on what amounted to a live electrical generator.

Saturday's history-making spacewalk has allowed the space agency to push forward with plans to launch the shuttle Atlantis and its major cargo -- a new European lab -- in December.

Shortly after undocking, the shuttle flew a full lap around the station, primarily so crew members could take pictures of the outpost's new configuration. Engineers were particularly interested in seeing how the newly mended solar wing was affected by the vibrations of undocking.

Computer problems forced pilot George Zamka to navigate the loop without help from software that provides information about the shuttle's path. But Discovery commander Pamela Melroy and Mission Control said he did a perfect job.

''We would never know that he doesn't have the data. It looks great,'' Mission Control said.

Astronaut Daniel Tani, who flew to the station aboard Discovery and will remain in orbit for two months, radioed the shuttle crew a last goodbye as they finished circling the outpost.

''I miss you already,'' he said. ''Fly safe. Get home safe. I'll see you on the ground.''

''Yep, we'll see you on the ground,'' Discovery commander Pamela Melroy replied.

Later, the crew planned to take another close-up laser survey of Discovery's wings and nose cap, this time to check for any possible micrometeroid damage. Inspections conducted earlier in the mission found no evidence of significant damage from debris shed during liftoff.

Discovery is scheduled to land Wednesday afternoon.

Whitson and Melroy are the first women to simultaneously manage two spacecraft in the 50-year history of spaceflight.

Whitson and her crew plan to move the compartment, named Harmony, to its permanent location next week.

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On the Net:

NASA: http://spaceflight.nasa.gov/

    Shuttle Undocks From Station, NYT, 5.11.2007, http://www.nytimes.com/aponline/us/AP-Space-Shuttle.html

Astronauts Revel in Wing Repair Success

November 4, 2007
Filed at 9:10 a.m. ET
By THE ASSOCIATED PRESS
The New York Times

HOUSTON (AP) -- Astronauts aboard the shuttle Discovery and the international space station reveled Sunday in their successful solar wing repair, and prepared to close the hatches between their linked spacecraft and part ways.

Crew members were transferring supplies and equipment between Discovery and the station Sunday morning and then planned to some enjoy time off.

They earned it after Saturday's history-making spacewalk.

Astronaut Scott Parazynski performed emergency surgery on the wing as it coursed with more than 100 volts of electricity. He did it while perched at the end of a 90-foot robotic arm and boom extension, farther from the safety of the station than any spacewalker had ever been.

The repairs allowed the crew to unfurl the wing to its full 115-foot length, making it possible for NASA to move ahead with plans to expand the station in the coming months.

''This one will go down as one of our biggest successes in (spacewalking) history,'' flight controllers told the crew in morning briefing documents. ''Words can not express how proud you made everyone with the execution by the entire team.''

The spacewalk -- the fourth for Discovery's space station visit -- wrapped up station construction work for the seven shuttle astronauts.

The crews planned to close the hatches on Sunday afternoon, and the shuttle is set to pull away Monday. Discovery is scheduled to land on Wednesday.

Astronaut Clayton Anderson, who has lived on the space station since June, was spending his last day there. He thanked flight controllers, other NASA workers and his wife, Susan.

''Part of me is ready to go and part of me wants to stay,'' he said.

The space station's three occupants have a lot of work to do after Discovery leaves.

They need to move the pressurized compartment that was delivered and installed by the Discovery crew -- and conduct three spacewalks -- before the planned December launch of shuttle Atlantis carrying the first of two new laboratories.

NASA still has to figure out what to do about a malfunctioning rotary joint that turns another set of the station's solar power wings toward the sun. Last weekend, a spacewalker found steel shavings inside the joint, apparently the result of grinding parts.

Discovery's crew will bring samples of those shavings back to Earth to help pinpoint the source of the trouble.

------

On the Net:

NASA: http://spaceflight.nasa.gov

    Astronauts Revel in Wing Repair Success, NYT, 4.11.2007, http://www.nytimes.com/aponline/us/AP-Space-Shuttle.html

Space Station Is Repaired

in Spacewalk

November 4, 2007
The New York Times
By JOHN SCHWARTZ

An astronaut on a daring spacewalk yesterday repaired a damaged solar array on the International Space Station.

Dr. Scott E. Parazynski, a former emergency room physician, mended wounds on the wing, which developed two tears while being deployed Tuesday.

If the procedure had not been successful, the array, on the left side of the station, might have had to be discarded. The loss of a solar array would have reduced the ability to produce power, possibly constraining future construction on the station.

Mission managers knew that wires had become snagged and had torn the array during deployment. But they did not know the nature of the snag. They had hoped that repairs would be a simple matter of moving a wire off a hinge.

Dr. Parazynski, riding on an extension of the station’s robotic arm to reach the damaged array, said his view of the repair site revealed a “hairball” of wire, with guide wire for the array caught in another wire running through the hinge connecting the panels.

Looking at a close-up view available from Dr. Parazynski’s helmet camera, Pamela A. Melroy, the commander of the space shuttle Discovery’s current mission, said, “Sounds like you have some surgery to do, Dr. Parazynski.”

He inserted the first “cufflink,” a wire-and-metal contraption created by the astronauts using instructions from the ground, into place along the array shortly before 9 a.m. Eastern time. That stabilized the area around the tears so he could work on the wire.

With the sun at his back and his shadow sharp against the brilliantly golden array, Dr. Parazynski began cutting wires, cautiously planning each snip in consultation with Ms. Melroy and mission controllers on the ground.

Dr. Parazynski took care to keep clear of the swaying array, occasionally dampening its motion with a prodder shaped like a hockey stick. He cut out two offending lengths of wire and moved on to insert the remaining cufflinks.

Astronauts inside the station then began the delicate process of extending the array to its full length, with Dr. Parazynski and Col. Douglas H. Wheelock, stationed at the base of the array, watching for any hint of trouble.

The cufflinks held. Cheers could be heard over the communications loop.

Concerns going into the spacewalk focused on electrical hazards and possible damage to space suits. A list of warnings read to Dr. Parazynski by Paolo A. Nespoli, the Italian astronaut who was choreographing the spacewalk from the station, included touching sharp edges of bolts, solar cells, hinges and other areas of the array.

“I’m not sure there’s much left to touch,” Dr. Parazynski replied.

Mr. Nespoli said, “We’re not even halfway through the warnings,” and went on to warn against touching areas with “pinch points” and high electrical current, which carry a risk of shock and “molten metal.”

During the procedure, Dr. Parazynski said he saw no sparks.

Dr. Parazynski, by coincidence, was one of the best astronauts for the unusual spacewalk. Now on his fifth trip to orbit, he has spent more time in spacewalks than all but four others in the history of the program. And, at 6 feet 2 inches, he is among the tallest astronauts and well-suited to work on the array from a safe distance.

“It’s a bit of a reach here,” he said at one point.

Ms. Melroy responded, “That’s what those monkey arms are for,” and then added, “Not many people in the office could do what you’re doing right now.”

To which Dr. Parazynski replied, “I hope they don’t have to.”

The only apparent slip-up came at the end of the spacewalk, which lasted more than seven hours. An errant set of needle-nose pliers floated away and could be spotted drifting below the station. Mission managers said the tool is not likely to pose a threat to the shuttle or station before falling back to Earth, but said they would track it on radar.

The successful repair makes it possible to shoot for launching the next module for the station, the European-made Columbus laboratory, early next month, said Michael T. Suffredini, the manager of the station program.

Even after the spacewalk yesterday, the station still has one major problem: a damaged rotary joint on the right-hand side.

The crew of Discovery will bring back some of the metal shavings from the joint when they return this week, as early as Wednesday. Those shavings, Mr. Suffredini said, will provide clues about which part is damaged.

A full inspection of the joint, which was scheduled to take place during this mission, is now likely to be pushed back into next year, as will any repair.

Mr. Suffredini said the station’s current power set-up, with one set of two arrays rotating and the right-side arrays parked but drawing a reasonable amount of sunlight, should give the station enough power to get through the December mission and perhaps well beyond.

The repairs made to the solar array should hold through the predicted end of United States involvement in the station program in 2015, Mr. Suffredini said. It did, however, leave the array looking as though it had acquired a dueling scar.

“The idea for this was to regain the functionality of the solar array,” Mr. Suffredini explained. “It wasn’t about looking good when it was over with.”

The array, he acknowledged, “Doesn’t quite look like we’d expected. But you know, it’s just like anybody — you have your baby, your baby is beautiful to you. Our baby is still beautiful to us.”

    Space Station Is Repaired in Spacewalk, NYT, 4.11.2007, http://www.nytimes.com/2007/11/04/science/space/04shuttle.html

Astronauts Conduct

Dangerous Spacewalk

November 3, 2007
The New York Times
By JOHN SCHWARTZ

Astronauts are conducting a risky spacewalk to repair a torn solar array on the International Space Station.

Dr. Scott E. Parazynski, riding on an extension of the station’s robotic arm, said that his close-up view of the repair site revealed a “hairball” of wire with guide wire for the array caught up in the wire running through the connecting the panels.

Mission managers knew that wires had become snagged and had torn the array in its deployment, but did not know the nature of the snag and had hoped that it would be as simple as moving a wire off of a hinge. The description by Dr. Parazynski, an astronaut who has been an emergency room physician, confirmed a description from Pamela A. Melroy, the commander of the mission, who was watching from inside the station with binoculars at the beginning of the spacewalk. “It doesn’t look like an easy, just rattle-it-and-shake-loose-the-grommet kind of situation,” she said.

With the close-up view now available, she said, “Sounds like you have some surgery to do, Dr. Parazynski.”

He replied, “I think so.”

The spacewalk calls for clearing the snag and then using five straps with ends like cufflinks to bind the damaged panels. Dr. Parazynski, a veteran spacewalker on his fifth NASA mission, is working to restore the structural integrity of the 110-foot-long solar “wing” so that it can continue to provide power to the orbital outpost.

Mission managers said that while the set-up for the spacewalk was arduous, and involved higher risk and less planning and practice than normally go into such activities , the tasks themselves might be accomplished relatively simply.

“It’s a snag clear; it’s not rocket science,” Dina Contella, the lead spacewalk officer for the mission, said in a briefing on Friday with reporters.

And though concern outside of NASA had run high over the possibility that Dr. Parazynski might suffer electric shocks, perhaps even a fatal one, from the solar array, the mission managers stressed at the Friday news conference that such an event was highly unlikely. Derek Hassmann, the lead flight director for the station, said that an astronaut would have to be touching the array with a metal part of his suit at a point in which the array’s insulation had come off, and have another part of the suit touch a different part of the array “in order to complete the circuit,” he said.

Still, the list of warnings read to Dr. Parazynski by Paolo Nespoli, who was choreographing the spacewalk from the station, was extensive, and included warnings about touching sharp edges from bolts, solar cells, hinges and other areas of the array. “I’m not sure there’s much less to touch,” Dr. Parazynski said.

“We’re not even halfway through the warnings,” Mr. Nespoli said, and went on to warn against touching areas with “pinch points” and high electrical current, which carry a risk of shock and “molten metal.”

Col. Douglas H. Wheelock is also taking part in the spacewalk, positioned at the base of the array to provide visual cues to Dr. Parazynski.

If the procedure does not work, the array might have to be jettisoned, and future construction on the station might be constrained by its reduced ability to produce power, especially since the solar arrays on the right-hand side of the station are currently parked because of mechanical problems with the rotary joint that helps point them toward the sun.

Derek Hassmann, the lead flight director for the station, said, “We need to address one of these two problems before we proceed” with further construction missions.

The job puts Dr. Parazynski farther from the safety of the airlock than any astronaut has gone in the history of the space station program. If there are problems — for example, glove damage or a failure of the suit’s oxygen supply — returning to safety could take somewhat longer than the 30 minutes that his backup oxygen supply would cover.

Mission managers say they are confident that despite the additional risk, Dr. Parazynski will be safe. Astronauts have covered exposed metal on his suit and tools with insulating tape to prevent arcing. Mr. Hassmann said that the likelihood of risk from shock was extremely small.

“We don’t expect there to be any issue,” he said.

    Astronauts Conduct Dangerous Spacewalk, NYT, 3.11.2007, http://www.nytimes.com/2007/11/03/science/space/03cnd-shuttle.html?hp

Spacewalk Canceled,

Torn Wing New Focus

November 1, 2007
Filed at 2:31 a.m. ET
By THE ASSOCIATED PRESS
The New York Times

CAPE CANAVERAL, Fla. (AP) -- NASA canceled Thursday's spacewalk to inspect a snarled joint for a set of solar panels and instead instructed its orbiting astronauts to go out a day later to try to fix a torn solar wing.

The newly ripped wing is now the more pressing of the two problems at the international space station, both of which involve the crucial power system and threaten to disrupt future construction work.

NASA fears the damage could worsen and the wing could lose all power-collecting capability and become unstable. If that happened, the wing would have to be junked, said NASA's space station program manager, Mike Suffredini.

''We've made it a priority to go repair it,'' Suffredini said Wednesday.

Engineers scrambled to put together a plan for a spacewalk as early as Friday to tackle the wing, which remains partially deployed. It ripped in two places as it was being unfurled by astronauts aboard the linked shuttle-station complex Tuesday, and a hinge may have been yanked and partially ripped.

Suffredini said engineers suspect the wing became snagged on a support for one of the wing's guide wires. They do not want to reel it in to make it easier to access for spacewalkers, for fear it could be further damaged.

The torn section of the wing cannot be reached with the space station's 58-foot robot arm. So NASA plans to attach the shuttle inspection boom to the station's robot arm, and put Scott Parazynski on the boom to free the snagged part of the wing.

It helps that Parazynski is tall -- 6-foot-2 -- and has long arms. NASA doesn't want him bumping the wing or touching its sunlight-collecting blankets. There would be no need to mend the tears.

''It's not really very far outside of our scope of experience, and I'm comfortable that it's something we're going to be able to put together,'' said flight director Derek Hassmann.

He added: ''It's going to be fast and furious over the next couple of days.''

Astronauts awoke Thursday to the repetitive ''o-wim-o-weh, o-wim-o-weh'' of ''The Lion Sleeps Tonight,'' a song sent up by their training team.

''You have made them look really good,'' Mission Control told the astronauts.

''That was a lot of fun,'' Discovery commander Pamela Melroy said. ''That certainly gets you going first thing in the morning.''

If more time is needed to prepare, the spacewalk will be deferred until Saturday. But NASA would prefer to attempt it on Friday in case something goes wrong and another spacewalk is needed to finish the job.

Meanwhile, on the opposite side of the space station from the torn wing, a rotary joint that controls the solar wings over there is out of action. A spacewalking astronaut discovered steel shavings in the right joint last weekend, the apparent result of grinding parts.

Suffredini said he and others will figure out what to do about the joint once Discovery undocks from the space station.

The space station can live with the reduced power caused by the two problems for now. But it poses huge challenges for NASA's plans to deliver European and Japanese laboratories on back-to-back shuttle missions beginning in December.

Suffredini said at least one of the problems will need to be resolved before shuttle Atlantis can lift off with Europe's lab. That launch is currently scheduled for Dec. 6.

NASA is under presidential orders to complete space station construction and retire its space shuttles by 2010, to make way for new rocketships that will aim for the moon.

Melroy acknowledged the emotional roller coaster of the past few days.

''What's holding us up together and keeping us all upbeat is that we're all doing something that we believe in so strongly and that we love, and we're having a ton of fun together doing it,'' the Discovery commander said at a news conference.

Halloween, for instance, did not go unnoticed in orbit.

Clay Anderson, who's winding up a five-month space station stay, wore a black cape as he went about his work. Daniel Tani, his replacement, wore a black eye patch.

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On the Net:

NASA: http://spaceflight.nasa.gov

Spacewalk Canceled, Torn Wing New Focus, NYT, 1.11.2007,
http://www.nytimes.com/aponline/us/AP-Space-Shuttle.html