NASA has told worried space fans that there has been no emergency on the International Space Station.
The statement followed the accidental broadcast of a medical drill on the official ISS livestream.
At 17:28 US Central Time (22:28 UTC) on 12 June 2024, footage from the livestream was replaced with a message stating that the feed had been temporarily interrupted.
There then followed audio apparently indicating that an astronaut on the Space Station was experiencing decompression sickness.
A voice asked the crew to “get the commander back in his suit, get it sealed,” following with “I would like you to check his pulse one more time.”
Concerned members of the public posted on social media, asking whether the situation that appeared to be unfolding on the ISS was genuine.
However, NASA denied there was any such incident on its International Space Station social media accounts.
The apparent emergency was later revealed to be a training drill taking place at SpaceX mission control centre in Hawthorne, California.
"There is no emergency situation going on aboard the International Space Station," the ISS X (formerly Twitter) account said.
"At approximately 5:28 p.m. CDT, audio was aired on the NASA livestream from a simulation audio channel on the ground indicating a crew member was experiencing effects related to decompression sickness (DCS).
"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.
"The International Space Station crew members were in their sleep period at the time. All remain healthy and safe, and tomorrow’s spacewalk will start at 8 a.m. EDT as planned."
On SpaceX's feed, a post promptly followed, stating "This was only a test. The crew training in Hawthorne is safe and healthy as is the Dragon spacecraft docked to the Space Station."
Decompression sickness explained
According to Harvard Medical School, 'decompression sickness' is the name given to injuries that are caused by a "rapid decrease in the pressure that surrounds you, of either air or water."
In the case of astronauts, decompression sickness, also known as 'the bends', could occur during a spacewalk as a result of sudden change in pressure caused by donning a spacesuit and exiting through the airlock.
It could be one of the biggest dangers on the International Space Station, but astronauts avoid risk of the bends by going through a 24-hour protocol before any extra vehicular activity (EVA) begins, to avoid the onset of decompression sickness.