Chinese astronaut orbitng Earth heard mysterious ‘knocking’ on his capsule
However, during his cosmic journey, Yang detected something that simply shouldn’t have been possible: a sharp ‘knocking’ sound repeatedly occurring. He examined the capsule, looked out the porthole, and inspected the panels, but couldn’t identify its source, even as the sound persisted.
Article source: https://www.express.co.uk/news/science/2186532/yang-liwei-chinese-astronaut-heard-mysterious-knocking-sound-from-space-vacuum-2003