Astronauts return to ISS after sheltering during air leak repair attempt

The trigger for the order was a worsening air leak in the transfer tunnel, known as PrK, leading to a section of the Russian segment of the station called the Zvezda service module.Russian cosmonauts, station commander Sergey Kud-Sverchkov and flight engineer Sergei Mikaev, attempted to fix the problem. Their escape route was the separately docked Soyuz MS-28 spacecraft.It is not the first time the station has had to deal with this problem - the cracks responsible have persisted on and off for around six years.However, following the arrival of a Russian cargo ship last month, the Russian space agency Roscosmos noticed a fresh slow pressure drop in the tunnel, prompting the decision to move beyond patchwork fixes and attempt a more extensive repair operation on Friday.But it was the method they were planning to use that prompted the order to take shelter, according to news agency Reuters.Kud-Sverchkov and Mikayev were said to be using a saw to try and get into an area to access the crack that was leaking air.NASA disagreed with the method they were using and mission control in Houston ordered five crew to take "safe-haven" procedures on the Dragon ship.