ISS crew returns after sheltering during air leak repair

Astronauts on the International Space Station have returned to normal operations after sheltering in a docked spacecraft. The crew took shelter because of a worsening air leak in the Russian segment. Five of the seven crew members went into the SpaceX shuttle Dragon Freedom on Friday. They put on their spacesuits and prepared for a possible evacuation. Two Russian cosmonauts, Sergey Kud-Sverchkov and Sergei Mikaev, stayed behind to fix the leak. They used a saw to try to reach the crack. Nasa ordered the five astronauts to take safe-haven procedures. Later, Nasa told them to come back to the station. The air leak has been a problem for about six years. It has persisted on and off. The leak is in a tunnel called PrK, which leads to the Zvezda service module. The station always leaks about half a pound of air per day, according to retired astronaut Chris Hadfield. When the leak increases to a pound or more, the crew must act. The cosmonauts planned a more extensive repair after a Russian cargo ship arrived last month. Roscosmos noticed a fresh slow pressure drop. Nasa disagreed with the method of using a saw. So the cosmonauts paused the repair. The crew was safe throughout the event. The ISS has been continuously operated since 1998 by a consortium including the US, Russia, Canada, Japan, and 11 European countries. It is the largest human-made object in space, as long as a football field.