It was detected at 1:45 a.m. tonight shortly before Russian cosmonauts Sergey Prokopyev and Dmitri Petelin began an already planned extravehicular activity. The cause and severity of the problem is not yet known at this time.

There is no danger to the crew, said Rob Navias, a Nasa spokesman through NasaTv, and efforts will be made in the coming hours to fix the problems on the Soyuz MS-22, which is the lifeboat and return to Earth for 3 of the 7 current crew members.

The discovery was made by Russian ground technicians who had noticed a significant leak of an unknown substance from the aft part of the Soyuz MS-22 capsule docked to the Rassvet module. Leakage clearly visible on video, in which it appears as a steady spillage of snow-like material. Simultaneously, a pressure drop in the capsule’s external cooling circuit had been shown. The cause of the leak is not known at the moment, whether it is due to the impact of some micrometeorite or a malfunction of the Soyuz systems.

There are currently seven astronauts on the Space Station (ISS): four who arrived in orbit on the SpaceX Crew-5 mission – Japan’s Koichi Wakata, Americans Josh Cassada, Nicole Mann and Russia’s Anna Kikina – the two Russians Dimitri Petelin and Sergey Prokopyev and American Frank Rubio who arrived on the Soyuz MS-22, which has now encountered the problem.

The Soyuz is also the shuttle that is expected to bring the 3 astronauts back to Earth at the end of the mission on March 28 and is intended as a rescue shuttle in case of any problems on the Station. If engineers assess that the Soyuz is no longer capable of bringing the astronauts back to Earth, a replacement shuttle capable of docking to the Iss in an automated manner could be launched.