CAPE CANAVERAL, Fla. – Astronauts took 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.
"Since you guys are cruising, we're running out of tasks," Mission Control called up as the spacewalk neared the four-hour mark.
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.
Shuttle commander Mark Polansky said neither he nor his crew mates were letting their guard down, despite the simple tasks, because "in my book, the last one you do is always the one that you have to watch out for the most."
Only a handful of 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."
That's the mileage, more or less, that the shuttle and station were expected to log during Monday's spacewalk, given an orbital speed of 17,500 mph.
Cassidy and Marshburn were so eager to get started on spacewalk No. 5 that they floated out an hour early as the linked spacecraft sped across the Atlantic, halfway between South America and Europe. Fifteen minutes later, they crossed over Italy; the toe and heel of the boot were clearly visible 220 miles beneath them.
Endeavour is scheduled to undock from the space station Tuesday, then spend three more days in orbit before returning to Earth on Friday.
The joint 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, at the outset of Monday's spacewalk 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.
To everyone's delight, Cassidy and Marshburn started out easy and soon were running well ahead of schedule without a single snag.
"If you go even slower, we'll get further ahead," astronaut David Wolf called out to Cassidy from inside. "Exactly," replied Cassidy. Later, as the spacewalkers tackled several extra tasks, Wolf reminded them again, "There's no hurry at all."
Mission Control officials say Cassidy's background as a Navy SEAL makes it difficult for him to slow down.
The only thing left undone was the opening of a platform for big spare station parts, which would have been too time-consuming.