China’s first astronaut Yan Liwei said he heard what sounded like someone knocking on the body of the spaceship during a mission in 2003.
The strange noises left him spooked, but he couldn’t see the cause as he stared out into space.
He claimed he never heard the sound again after returning to Earth.
Several Chinese astronauts who have entered Space have also heard the noise, he claimed.
But he assured them that it is a “normal phenomenon, so there is no need to worry”.