When China’s first astronaut, Yang Liwei, returned to earth he was injured because of a design flaw in the shuttle. His face was covered in blood from a split lip. Most people were unaware he came back anything other than perfectly healthy.
Workers opened up the door, cleaned Liwei’s face and shut him back in. It was only after he was cleaned up that they put him on camera and China experienced its victory without blood marring it.
The reason Liwei was injured was because of excessive G-force. Due to the way the spacecraft slows down, the astronaut ends up being affected by a greater force of gravity. Liwei was also subject to flaws in the spacecraft during launch.
He was affected by infrasonic waves, which caused his body to resonate. Infrasonic waves can be deadly and injure organs. Liwei faced some serious dangers as the first astronaut.
It is not entirely clear why exactly China censored the information that Liwei was covered in blood when he returned. However, it is thanks to Liwei that later space crafts were designed more safely for future astronauts.