Moscow (Agencies): Two Russian cosmonauts, Dmitry Kondratyev and Oleg Skripochka, have begun a spacewalk, their second venture outside the International Space Station in less than a month.

The cosmonauts are expected spend about six hours outside the orbiting laboratory doing tasks, including installing equipment for experiments on sensing earthquakes and lightning.

They also are gathering two panels that had been left outside the station to expose various materials to space, an effort to determine what materials are best for space construction.

One Russian, two Americans and an Italian remain inside the station during the Wednesday spacewalk. A video feed from Russian mission control outside Moscow reported the spacewalk beginning about 15 minutes late.