Two Russian cosmonauts, Vladimir Dezhurov and Mikhail Tyurin, are expected to perform a space walk on the International Space Station (ISS) at about 04:00 PM Moscow time. Frank Culbertson, an American astronaut and the commander of Expedition 3 to the ISS, will survey and control their actions from aboard the station. This information was unfolded by the Russian Mission Control. Mission Control's officials also stated that this unplanned space walk would be conducted in order to repair the malfunction, which had appeared in the docking unit during the docking of the Russian Progress M1-7 cargo space ship. Experts believe that the 4mm gap between the ship and the station's docking unit has been caused by an object, which now prevents the tight joining of the two space vehicles. According to the Russian Mission Control, the space walk may last from 3 to 6 hours because of the mission's difficulty. The cosmonauts will have to use the electric motor of the docking unit to manually un-dock the Progress M1-7 to the distance of not more than one meter from the station. Then, they will examine the docking unit from within. The space walk period will decrease if they successfully remove the object located in the gap between the ship and the docking unit. If the malfunction is more serious, the Mission Control will set the cosmonauts another mission. The Russian Mission Control also reported that the forthcoming launch of the American Endeavour space shuttle totally depended on the success of the aforementioned "repair works." Experts believe that the shuttle will be unable to dock the ISS if the Russian cargo ship is not tightly secured to the station. Otherwise, the dynamic blow of the docking shuttle may set the Russian ship "swaying" which might damage the ISS. There has already been a similar incident in space. In 1987, the Kvant module was not secured either. The cosmonauts who performed a space walk, successfully repaired the malfunction.