Three astronauts are stuck on China's space station without a safe ride home

"With their original spacecraft deemed unsafe, Chen and his crewmates instead rode back to Earth on the newer Shenzhou 21 craft that launched and arrived at the Tiangong station October 31. The three astronauts who launched on Shenzhou 21-Zhang Lu, Wu Fei, and Zhang Hongzhang -remain aboard the nearly 100-metric ton space station with only the damaged Shenzhou 20 craft available to bring them home."

"China's line of Shenzhou spaceships not only provide transportation to and from low-Earth orbit, they also serve as lifeboats to evacuate astronauts from the Chinese space station in the event of an in-flight emergency, such as major failures or a medical crisis. They serve the same role as Russian Soyuz and SpaceX Crew Dragon vehicles flying to and from the International Space Station."

"Another Shenzhou spacecraft, Shenzhou 22, "will be launched at a later date," the China Manned Space Agency said in a statement. Shenzhou 20 will remain in orbit to "continue relevant experiments." The Tiangong lab is designed to support crews of six for only short periods of time, with longer stays of three astronauts. Officials have not disclosed when Shenzhou 22 might launch, but Chinese officials typically have a Long March rocket and Shenzhou spacecraft on standby for rapid launch if required."

Shenzhou 20 suffered damage in orbit, leading Chen and his crewmates to return onboard Shenzhou 21, which launched October 31 and docked at Tiangong. Three astronauts who launched on Shenzhou 21—Zhang Lu, Wu Fei, and Zhang Hongzhang—remain aboard the nearly 100-metric ton station with only the damaged Shenzhou 20 available to bring them home. Shenzhou vehicles act as both transport and emergency lifeboats, analogous to Soyuz and Crew Dragon. Shenzhou 22 will launch later, while Shenzhou 20 will stay in orbit to continue experiments. Tiangong supports six for short periods and long stays for three.

Read at Ars Technica