China’s first astronaut Yang Liwei has claimed that during her first mission in 2003 she heard noises which were not caused by her team members.
Yang Liwei said the noise was like someone was knocking the body of the space shift. He went outside to check but there was no one and nothing had hit the spaceship.
He was not alone to hear these noises other members of Shenzhou 6 and Shenzhou 7 missions also reported to hear such noises.
They tried to explain what was the cause of the noise but had failed to do so. Many believe it was caused by aliens who wanted to indicate their presence.