Two Russian crewmembers at the International Space Station have begun a spacewalk to install new equipment and inspect the orbiting outpost's exterior.

Gennady Padalka and Mikhail Kornienko are to mount devices that will ease the movement of crew on future spacewalks. They are also to replace an antenna, clean windows of one of the station's modules and take pictures of its outer surface. The duo is also set to remove an experiment intended to study the impact of the space plasma environment on the station.

Monday's six-hour spacewalk is 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.