Yang Liwei, the first person sent into space by the Chinese space program, recently described his experience in space, mentioning strange noises he heard during his mission.

Yang tried to take notice of every single detail from his voyage. He said he saw a very bright light shining for a split second during the short night in space, but when he tried to find its source, the light quickly disappeared. Nothing appeared amiss with the dashboard in the space lab.

Another strange phenomenon Yang encountered was randomly-occurring knocking noises, which didn’t last for long and followed no discernible pattern. According to Yang, the knocking didn't sound like it was coming from inside the spacecraft, but rather like someone was knocking at the exterior with a wooden hammer.

Scientists tried to recreate the sound after Yang returned to Earth, but the efforts never succeeded. Nevertheless, he reassured astronauts who came after him that there was no need to panic if they came across similar phenomena.

The work of astronauts is full of difficulties and hardship, testing the mental and physical strength of the pioneers. The experience and skills accumulated in Chinese space science come only thanks to hard work done by earlier generations of astronauts.