(AP) -- Two Russian cosmonauts on Wednesday conducted a five-hour-long spacewalk outside the International Space Station to install equipment for experiments on sensing earthquakes and lightning.

In their second venture outside the space station in less than a month, Dmitry Kondratyev and Oleg Skripochka also gathered 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 remained inside the station during the Wednesday spacewalk.

The mammoth station consists of 10 modules built by the United States, Russia, Canada, Japan and the 18-nation European Space Agency.