"It's going to be a challenge for us, but we're looking forward to going out there and doing our part to help the station," Noreiga told SPACE.com CEO Lou Dobbs in a space-to-ground interview Wednesday.

Added Tanner: "I think it's going to be real exciting."

Here's the situation:

Two thin cables designed to tighten a glimmering blue-and-gold blanket on one of the wings failed to do so when the array was unfolded Sunday like a huge accordion in space.

A spacewalking inspection Tuesday showed that the cables jumped off their reel-and-pulley assemblies, leaving the giant solar panel a bit slack.

A tight blanket is crucial to making sure the fragile solar wing would not be damaged by forces imparted upon it when U.S. shuttles and Russian spacecraft dock at the station.

What's more, the loose cables must be taut so the arrays can be retracted prior to a planned repositioning of the station's power tower in late 2002 or early 2003.

"We would have to pull the cables in to retract [the arrays]," NASA launch package manager Ron Torcivia told SPACE.com during a news briefing late Tuesday. "And in order to do so, we would have the astronauts actually pull those two loose cables forward."

Look for the impromptu repair job to unfold during a spacewalk scheduled to begin at 11:51 a.m. Eastern Standard Time (16:51 GMT) Thursday. The six-hour excursion will be broadcast live on SPACE.com.

A plan approved by mission managers Wednesday calls for Tanner and Noriega to use a hook-like tool to pull the loose cables back onto their reel-and-pulley assemblies. The cables then will be rewound a bit to tighten the slack blanket.

What sounds relatively easy, though, might in fact prove to be difficult.

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NASA astronauts Michael Foale and John Grunsfeld have spent the past few days trying to simulate the job in a giant NASA pool that serves as a training ground for spacewalkers. Pulling off the task on Earth has taken repeated attempts.

Consequently, Tanner told Dobbs he'd be "overjoyed if we get it on the first try."

Mission Endeavour

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"I don't anticipate that," the veteran spacewalker added. "We're going to keep working at it, and I think [ultimately] we can do it."

The spacewalkers face another important job Thursday: Mounting a device designed to gauge whether the new solar wings create a shock hazard to astronauts working outside the station.

Stretching 240 feet (73 meters) from tip to tip, the arrays are capable of generating 64 kilowatts of direct current (DC) power - or enough electricity to adequately supply 30 average American homes (minus air conditioning).

The high-voltage arrays, in fact, are so powerful that under certain circumstances, they can create an electric arc that would shoot out from metal station structure into the surrounding environment.

In a worst-case scenario, NASA officials say the resulting shock could be similar to being struck by a deadly lightning bolt.

Two electrical grounding rods known as Plasma Contactor Units already are mounted on a girder-like truss located just below the electric power tower, where Tanner and Noriega will be carrying out the repair job.

The problem is that NASA engineers are uncertain whether the grounding rods - which are designed to neutralize dangerous electrostatic discharges - will work as advertised.

Tanner and Noriega, as a result, will be setting up a so-called "Floating Potential Probe" atop the station's five-story power tower, which serves as a base for the mammoth solar wings.

The job was added to the shuttle crew's "to-do" list in mid November after exhaustive engineering analysis showed the grounding rods might not operate as expected. The so-called FPP device is expected to help NASA determine if a shock hazard in fact exists.

The uncertainty about the work environment, meanwhile, will prompt NASA to put in place extra safety measures to protect Tanner and Noriega during the sortie outside the station.

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First, both of the electrical grounding rods will have to be up and operating before the astronauts are sent outside to work on the slack blanket.

In addition, ground controllers will maneuver the 97-ton station and its twin solar wings into a position that effectively will inhibit the generation of electricity.

Expedition One

Look here for the latest news about the first crew to live and work aboard the International Space Station.

"So we're being doubly cautious by eliminating the concern in the first place," said NASA lead flight director Bill Reeves.

Ground controllers quietly put the same so-called "inhibits" in place before Tanner and Noriega wired up the new solar wings during a spacewalk Tuesday.

Both told Dobbs they weren't troubled by the potential shock hazard during that foray.

"You know, we worried a lot about that in the last couple of months and frankly, yesterday, I didn't even think about it," Tanner said.

But there were plenty of people on the ground and inside the shuttle fretting about the potentially dangerous situation.

"They were thinking about it in the crew module -- and on the ground, they're thinking about it all the time," Tanner said.

But, he added: "We've got three inhibits to a hazardous condition. All three of those inhibits were invoked [Tuesday], and we were in no danger."

The spacewalk will be the final one of three planned for Endeavour's mission.

Coming up Friday: The Endeavour astronauts plan to float inside the station to meet up with its first full-time tenants - U.S. astronaut Bill Shepherd and his two Russian colleagues, Yuri Gidzenko and Sergei Krikalev.

The Endeavour astronauts will deliver Christmas presents, fresh fruit and a small load of supplies to the station crew during a hatch-opening "welcome ceremony" scheduled for 9:30 a.m. EST (14:30 GMT) that day.

The two crews will bid adieu Saturday as Endeavour pulls away from the station and heads off on a two-day trip back to Earth. The winged spaceplane and its five astronauts remain scheduled to land at Kennedy Space Center at 6:19 p.m. EST (23:19 GMT) Dec. 11.