太空中的神秘敲击声（英文）

Chinese Astronaut Puzzled by “Knocking Sound” in Space

Imagine you’re alone in a tiny spacecraft—it’s your first time up there,all alone in endless space.Then suddenly—a knocking sound.That’s what happened to Yang Liwei,China’s first man in space,on his maiden^1 flight in2003.In a recent interview,he has now recalled hearing＂someone knocking the body of the spaceship just as knocking an iron bucket with a wooden hammer＂.