Space agency says the clip was from a training exercise which was accidentally put on YouTube,

Nasa has confirmed audio shared widely on social media of astronauts in distress was a simulation broadcast on its YouTube channel in error.

In the clip, intended to be used for training purposes, a voice said an astronaut on the International Space Station (ISS) had a “tenuous” chance of survival.

The broadcast of the clip on Wednesday evening sparked speculation online about a possible emergency in space - but Nasa said all members of the ISS are safe.

“This audio was inadvertently misrouted from an ongoing simulation where crew members and ground teams train for various scenarios in space and is not related to a real emergency,” it said on the ISS X page.