MOSCOW - Two Russian crewmembers at the International Space Station on Monday ventured outside the orbiting outpost to install some equipment and check the exterior.

During a spacewalk that lasted 5 1/2 hours, Gennady Padalka and Mikhail Kornienko mounted devices that will ease the movement of crew on future spacewalks.

They also replaced a communications antenna, cleaned windows of one of the station's modules and took pictures of its outer surface. In addition, the duo removed an experiment intended to study the impact of the space plasma environment on the station.

Monday's spacewalk was the 10th for Padalka, who has spent more time in space than any other human.

The other crewmembers - NASA astronauts Scott Kelly and Kjell Lindgren, Russian Oleg Kononenko and Kimiya Yui of the Japanese space agency - remain inside the station.

On Monday, the crew for the first time tasted red romaine lettuce leaves grown on the space outpost as part of an experiment to harvest plants in zero gravity. They left some for Padalka and Kornienko to sample after their return.