Russian cosmonauts from the 2nd permanent expedition to the International Space Station /ISS/ Vladimir Dezhurov and Mikhail Tyurin are preparing for their first space walk which will begin within next hour, it was said at the Russian Mission Control Centre in Korolyov, outside Moscow. The cosmonauts are "checking the airtightness of Orlan spacesuits and the air lock of the new Russian docking unit Pirs, through which they are expected to emerge onto the ISS surface," it was said at the centre. The aim of their walk is to bring the Pirs docking unit into a functioning state. To do so they will attach to this unit a Russian-made jib which will later be used to unload arriving Russian cargo ships. Besides that, they will fasten a valve to the air lock, and link the electrical connectors of the Pirs docking unit and the Russia's Zarya cargo module. On the station surface they will also put additional railing to ease the moving of cosmonauts about its surface, it was indicated at the centre. American astronaut Frank Culbertson, commander of the 2nd permanent ISS expedition, will watch the Russian cosmonauts from the Zarya module and, if necessary, will be ready to get out to help them, it was reported at the centre. The walk is expected to take 4-4.5 hours and will be filmed by a television camera installed on the surface of the station, the centre said.