Preparations have begun at the International Space Station /ISS/ for a space walk by Russian cosmonaut Vladimir Dezhurov and US astronaut Frank Culbertson, commander of the 3rd permanent expedition to the ISS, said Russian Mission Control on Monday. Extra vehicular activities will begin in the early hours of Tuesday, at 00.01 - 00.05 Moscow time. The total period the cosmonauts are going to spend in space will be around 6 hours. Mission control specialists say that the cosmonauts are to prepare the Kursk radar system to ensure the docking with the Russian mooring unit Pirs of "freighter and manned spacecraft arriving at the station". This requires installing an aerial and attaching the necessary cables and apparatus to it Also, the cosmonauts will test a cargo boom installed near the mooring unit and designed to unload cargo from spacecraft. They will also check the new solar batteries and film them. The third crew member - Mikhail Tyurin - will be observing them and monitoring their actions in free space," it was noted at Mission Control.