Three Chinese astronauts planned to come back to Earth this week.
Their names are Chen Dong, Chen Zhongrui, and Wang Jie.
They must wait because something may have hit their spaceship, Shenzhou-20.
Experts are checking the ship to make sure it is safe.
Before the problem, the three astronauts gave the station key to a new crew.
The new crew came on Shenzhou-21.
One of them is Wu Fei, only 32 years old, the youngest Chinese person in space.
China’s space agency says the delay is for the astronauts’ safety and health.
No new date for the return has been given yet.
Keeping astronauts safe can be hard.
Last year, two United States astronauts also had to stay in space much longer than planned because their ship had problems.