Two astronauts climbed out of an airlock on the international space station Saturday, starting a spacewalk to fix the complex's rail transporter and test whether a boom can be used to make repairs to the space shuttle.

The planned 6 1/2-hour jaunt, which began as the space station passed over Asia 220 miles below, was the first spacewalk for Mike Fossum and the fourth for British-born Piers Sellers.

"Enjoy the view, gentlemen!" NASA communicator Megan McArthur said from Houston.

Before exiting the space station, Sellers asked for an update on the World Cup and was told the finalists were Italy and France. Sellers and his crew mates on the space shuttle Discovery were launched on their trip to the space station on Tuesday, before the finalists were known.

Click here to visit FOXNews.com's Space Center.

The spacewalkers quickly dispatched of their first task, immobilizing a cable cutter on the station's mobile transporter, or railroad car, and rerouting a cable through it. A duplicate cable cutter accidentally cut a cable leading to the transporter late last year, and NASA wanted to make sure it does not happen again because the cable is a conduit for power, data and video images.

The transporter moves along the space station and is used for constructing the complex. The severed cable will be replaced during a second spacewalk set for Monday.

The spacewalkers were then to test whether a new robotic boom, with astronauts attached at the end, could be used for inspecting or making repairs to hard-to-reach places on the shuttle's underside. Fossum and Sellers planned to simulate repair-related movements while at the end of the boom, which will be attached to the shuttle's 50-foot robotic arm.

"Have fun today bouncing on the boom (sounds like a new country song)," flight controllers in Houston wrote earlier in a daily electronic message to the astronauts.

The technique was developed to make sure there is never a repeat of the Columbia disaster, which killed seven astronauts in 2003. Foam from the shuttle's external tank struck Columbia's wing during launch, creating a breach that allowed fiery gases to penetrate the shuttle during the return flight to Earth.

Fossum and Sellers may get a chance to use the boom for a real repair on their third spacewalk, now scheduled for next Wednesday. NASA managers are evaluating whether a piece of fabric filler protruding from the thermal tiles on Discovery's belly needs to be removed by the spacewalkers.

Two pieces of gap filler had to be removed from Discovery's belly during a spacewalk last year because of concerns they would cause problems during re-entry.

In their morning message, flight controllers told the Discovery crew that they wanted to take additional pictures of slightly damaged thermal blankets using a camera on the space station.

NASA managers do not think two of the blankets pose any problems but want to make sure the other two small blankets don't tear off during re-entry into Earth's atmosphere. The thermal blankets are used to protect the shuttle against searing heat during ascent and descent.

The flight controllers also had a request for the shuttle crew: Stop pouring unused drinks down the shuttle's toilet. "An example of how closely Big Brother watches," they wrote.

The space shuttle crew awoke Saturday to "God of Wonders," a popular Christian music recording chosen by Fossum's family.

"I do think it's particularly appropriate as I prepare to step outside for about 4 1/2 trips around this chunk of creation we call Earth," Fossum radioed Houston.