The oxygen supply has just failed in part of the ISS,...

The oxygen supply system on the Zvezda module in the orbital laboratory went down late Wednesday, but a second system in the American segment is functioning normally, a Roscosmos spokesman told AFP.

“Nothing threatens the safety of the crew and the ISS,” the spokesman said, adding that this repair work to fix the problem would be carried out on Thursday.

The problem arose after three new crew members – two Russian cosmonauts and one American astronaut – reached the ISS on Wednesday to increase the number of current crew members to six.

The problem is the recent incident on the ISS, the first module of which was launched over two decades ago in 1998 after the crew discovered an air leak on board in August.

Roscosmos emphasized at the time that the leak was not significant and posed no danger. Part of the problem, however, was figuring out exactly where it was coming from.

The crew believe they have found the source of the leak. The Roscosmos spokesman said he would receive specific instructions from mission control to carry out future work on the problem.

Veteran Russian cosmonaut Gennady Padalka, quoted by the RIA Novosti news agency, said Russian equipment aboard the ISS was well past its expiration date.

“All the modules in the Russian segment are exhausted,” said Padalka, who holds the world record for most days in space.

He added that the equipment was only intended to be used for 15 years while it was now two decades old.

© Agence France-Presse