"Spacecraft communicator James Kelly said flight controllers were analyzing their data but said it is not yet known if the alarm was actually triggered by a leak or whether the situation was caused by a faulty sensor or by a problem in a computer relay box that sends data and commands to various systems on the station," NASA public officer Joshua Buck told Sputnik.
It was also reported in a live NASA TV update that there has been no confirmation about what caused the alarm.
"The Expedition 42 crew members are safe and in good shape inside the Russian segment of the International Space Station following an alarm in the U.S. segment at about 4:00 a.m. EST. [09:00 GMT]," Buck said.
The current ISS crew comprises specialists from the United States, Russia and the European Union. Expedition 42 includes NASA's Barry Wilmore and Terry Virts, Roscosmos' Elena Serova, Alexander Samokutyaev and Anton Shkaplerov, and the European Space Agency's Samantha Cristoforetti.
