China's Shenzhou-21 spaceship undocks from space station combination

China's Shenzhou-21 crewed spaceship undocked from the space station combination on Friday and will commence the return mission of sending the Shenzhou-20 astronauts back to Earth, according to the China Manned Space Agency (CMSA).

The spaceship separated from the space station combination at 11:14 a.m. (Beijing Time) and will later re-enter the atmosphere and return under ground command control, with astronauts Chen Dong, Chen Zhongrui and Wang Jie on board.

The Shenzhou-20 spacecraft does not meet the requirements for the astronauts' safe return and will remain in orbit to continue relevant experiments, said the CMSA.

Tiny cracks have been found in the return capsule's viewport window, which are most probably caused by external impact from space debris, according to the CMSA.