A pair of spacewalking astronauts left the safe confines of the international space station Tuesday to take care of a little outside maintenance.

Russian Gennady Padalka (search) and American Mike Fincke (search) floated outdoors in the early-morning hours, on their third spacewalk in just over a month. This time, the work involved relatively mundane housekeeping chores, such as installing laser reflectors and antennas for a new type of cargo ship due to arrive in another year and swapping out science experiments.

At the end of June, the men had to make their way across the entire space station to reach a fried circuit breaker that needed to be replaced on the U.S. side of the orbiting outpost. It took two spacewalks to accomplish the job; a spacesuit problem cut short their first foray.

All of the tasks on Tuesday's lineup were on the Russian side of the 220-mile-high complex, just a short hop from the main exit, making for a much easier endeavor.

The European Space Agency (search) is working on a cargo ship to supplement the U.S. and Russian vessels that fly to the space station. The grounding of NASA's shuttles following last year's Columbia disaster highlighted the need for a more diversified fleet.

To prepare for Europe's supply ship, which has been in the pipeline for years and is running late, Padalka and Fincke had to hook up antennas and remove outdated laser reflectors and put in newer models. The six old reflectors were built in the late 1990s and have been in orbit since 2000, and the new ones will make it easier for the unmanned ships to close in and pull up, NASA (search) officials said.

In addition, a TV camera needed for the docking of the new supply ships already is broken, and the spacewalkers had to disconnect its electrical cable. The camera will be replaced by a future crew.

Padalka and Fincke — more than halfway through a six-month mission — left the space station empty during their spacewalk. In what is becoming routine, although not preferred, flight controllers in Moscow and Houston kept watch over the vacated outpost.

The halt in shuttle deliveries has reduced the station crew size from three to two. Until this year, someone always remained in charge inside during a spacewalk.

Padalka and Fincke will venture out once more, early next month, again in Russian spacesuits. The U.S. spacesuits on board are unusable because of inadequate cooling; engineers have yet to pinpoint the problem, after more than two months of analysis.