Two astronauts will venture outside the U.S. space shuttle Endeavour again Thursday to perform surgery on the international space station's robot arm.
In the last of three spacewalks this week, Endeavour crewmen Franklin Chang-Diaz and Philippe Perrin will replace a faulty joint on the mechanical arm.
Mr. Perrin, a French astronaut, told reporters that the spacewalk, called an EVA by the U.S. space agency, is important for future space station construction. "You're talking about a critical EVA," he explained. "It's true that we need that arm to be working for the rest of the station assembly, but actually it's a very simple EVA."
The robot arm repair is part an eight-day shuttle maintenance and supply visit to the space station. Endeavour has also carried up three new U.S. and Russian crewmembers to replace the trio in orbit since December.
On Tuesday, outgoing station astronauts Dan Bursch and Carl Walz set a U.S. space endurance record, surpassing the 188 days Shannon Lucid spent on the Russian station Mir.
It falls well short of the world space endurance record of 438 days established in 1996 by Russian cosmonaut Valery Polyakov aboard Mir. Even so, Dan Bursch says flying in close quarters with the same people all the time can be trying, even if the crewmembers are good friends. His comment suggests that he, Carl Walz, and cosmonaut Yuri Onufrienko have bickered from time to time.
"I think it's just living in the same confined area with anybody," said Dan Bursch. "If you think about taking a family trip, whether it's with your spouse or your family and never getting out of the car, you can imagine some problems are going to crop up, no matter how well you get along. That's about what it amounts to."
The replacement station crew, astronaut Peggy Whitson and cosmonauts Valery Korzun and Sergei Treschev, will face the same social situation until October, but Ms. Whitson notes that based on nearly one week in space, she is not daunted. "It's going to be even better than I expected," she said. "I'm really looking forward to this."