Shuttle Astronauts Rocket Through Last Spacewalk of Mission

Astronauts completed the last spacewalk of their shared shuttle and station mission Monday, breezing through some rewiring, camera setups and other outdoor chores.

Christopher Cassidy and Thomas Marshburn got so far ahead on the flight's fifth spacewalk that they even took on extra work, a welcome change from earlier excursions that were bogged down by balky equipment and other obstacles.

"We're out of tasks," Mission Control finally called up.

Only one item was left undone. Mission Control was reluctant to have the spacewalkers take on a drawn-out storage platform job, given the time remaining.

The spacewalk ended up lasting just under five hours and set the stage for shuttle Endeavour's scheduled departure Tuesday.

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Compared with the previous outings, this one included a hodgepodge of relatively mundane jobs.

The spacewalkers rearranged electrical hookups for a pair of gyroscopes, giving them separate power supplies, and folded down a piece of popped-up insulation on a small robot hand at the international space station. Then they hooked up two TV cameras on the brand new porch of a Japanese lab, installed by the two crews last week. The cameras will assist in experiment work on the porch and in the docking in two months of a Japanese cargo carrier.

"Congratulations, you guys just completed the ... assembly," Mission Control radioed once the second camera was secured. Japan's enormous $1 billion lab, named Kibo, or Hope, required three shuttle flights and took more than a year to finish.

"I can verify from up close it is, indeed, a beautiful laboratory," Marshburn said.

Shuttle commander Mark Polansky had cautioned his crewmates to keep their guard up, despite the simple tasks. Only a few other shuttle flights have had five spacewalks squeezed into them.

"Most shuttle crews are content with three or four," Mission Control said in a morning message. "Today, you'll be joining a very select group by doing your fifth! Thanks for going the extra mile ... or the extra 125,000 miles as the case may be."

With the spacewalk coming in under five hours, the total mileage ended up being closer to 90,000, given an orbital speed of 17,500 mph.

The five spacewalks together spanned a total of 30 hours.

With all that accomplished, Endeavour is scheduled to undock from the space station Tuesday afternoon, then spend three more days in orbit before returning to Earth on Friday.

The joint week-and-a-half mission created the largest space gathering ever, with 13 people. Seven of them will be coming back on the shuttle.

Cassidy took his time, as promised, during Monday's spacewalk in order to keep his carbon dioxide levels down. His first spacewalk, last Wednesday, had to be cut short because of elevated carbon dioxide levels in his suit. He made it all the way to the end of Friday's outing, despite a slight buildup.

No increase was noted Monday, and his metabolic rate was brisk but steady, officials said. Nonetheless, he went through the carbon-dioxide absorber in his suit more quickly than his partner's.

That prompted Mission Control to skip the one remaining chore, the opening of a platform for big spare station parts. Flight director Holly Ridings said there barely would have been enough time to perform the operation, so she decided to play it safe and save the job for future spacewalkers.

"We could not be happier with the success that we've had," she told reporters.

Mission Control officials said Cassidy's background as a Navy SEAL makes him go at things pretty aggressively, even when he's 220 miles up.