Astronauts have had to use tape to temporarily fix a tiny hole on the International Space Station.
Flight controllers noticed a drop in air pressure overnight on Wednesday, and alerted the crew.
The air leak was the result of a hole in a Soyuz aircraft attached to the Russian segment of the ISS.
The hole in question was only two millimetres in diameter, but could have caused serious consequences for the crew if left unfixed.
One astronaut had to plug the hole with his thumb while supplies were found to fix the problem.
The former astronaut Chris Hadfield took to Twitter to explain how such issues are typically dealt with, using durable 'Kapton' tape and a sealant called epoxy.
— Chris Hadfield (@Cmdr_Hadfield) August 30, 2018
Efforts are under way to establish the cause of the leak.
In a statement, the agency said: "Throughout the day, the crew was never in any danger, and was told no further action was contemplated for the remainder of the day."
Yesterday showed again how valuable our emergency training is. We could locate and stop a small leak in our Soyuz, thanks to great cooperation between the crew and control centres on several continents. pic.twitter.com/Jo0MnIIprL
— Alexander Gerst (@Astro_Alex) August 31, 2018