CAPE CANAVERAL, Fla. -- Spacewalking astronauts rambled around the outside of the International Space Station Saturday, laying the foundation for a planned expansion of the 17-story outpost early next year.

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With the station's third full-time crew working inside the complex, Daniel Barry and Patrick Forrester traipsed across the outer hull of the U.S. Destiny science laboratory, hooking up handrails and power cables in advance of a February 2002 outpost construction mission.

"I'll bet the Expedition Three crew thought they had squirrels in the attic today," Forrester joked as he and his partner wrapped up the day's work outside the orbital research facility.

"Yeah, I bet they did," Barry replied.

Like an initial spacewalk earlier in the week, Barry and Forrester remained intently focused on the job at hand as visiting shuttle Discovery and the station flew in tandem 246 miles (394 kilometers) above the planet.

But this time, the two took a moment or two to take in the panoramic view.

After a heads-up from Mission Control, the spacewalkers spied a rejuvenated Tropical Storm Chantal as the swirling weather system churned over the Caribbean Sea, heading west toward Mexico's Yucatan peninsula.

They posed for pictures in front of shuttle cockpit windows, and then working two stories above their mothership, they came into view of station cameras being operated by the outpost's new skipper.

"We have a great view that we weren't expecting to have - that Frank Culbertson is shipping over from an ISS camera," shuttle pilot Rick Sturckow told the spacewalkers.

"Tell Frank `Thanks,'" Barry replied. "I'm waving at him now."

And during the course of their sortie, the two also spotted a glimmering curtain of light on the horizon as the joined shuttle-station complex passed from the dark to the sunlit side of Earth.

"That is an unbelievable sunrise," Barry exclaimed. "It's all different shades of red, all different shades of blue."

For the most part, though, the spacewalkers were workmanlike as they crawled around the shiny lab, installing handrails on both its starboard and port sides. Barry and Forrester also strung 45-foot (13.6-meter) electrical cables along the metal bars - a job that proved to be a bit tricky.

Working side by side, the astronauts found it to be quite a stretch to unwind the coiled cable between them. Only the lengthy arms of lanky Barry made the work possible.

"Sometimes it's nice to have that long wingspan working for you," said Sturckow, who was directing the spacewalking excursion from the flight deck of Discovery.

"Occasionally it comes in handy, but then again, those long feet tend to bang into stuff," Barry joked. "So you know, it's a tradeoff."