Shenzhou 21 Astronauts Face Uncertain Future on Tiangong Station

Three astronauts aboard China’s Tiangong space station are currently without a reliable means of returning to Earth. The crew, part of the Shenzhou 21 mission, arrived at the station on October 31 for a planned six-month stay. However, their scheduled ride home was rendered inoperable after the Shenzhou 20 spacecraft, which had been docked to Tiangong, was damaged by a space-debris strike.

The Shenzhou 20 spacecraft, which was supposed to facilitate the astronauts’ return, suffered structural damage, leaving the Shenzhou 21 crew in a precarious situation. On November 13, the Shenzhou 21 spacecraft transported three different astronauts back to Earth, further complicating the current mission aboard Tiangong.

Emergency Protocols in Place

Despite the immediate risks, there is a contingency plan in place. According to SpaceNews’ Andrew Jones, the China Manned Space Agency maintains a Long March 2F rocket and a Shenzhou spacecraft at the Jiuquan Satellite Launch Center in a state of “near readiness” during crewed missions. If an emergency arises, this backup lifeboat can be launched to Tiangong within as little as 8.5 days. The countdown for this potential launch has likely already commenced, as the absence of a safe return option qualifies as a significant contingency.

Chinese space officials have indicated that the Shenzhou 22 spacecraft will be launched to Tiangong, although a specific timeline has not been disclosed. They stated that the launch would occur “at an appropriate time in the future.” The urgency of this situation is evident; prolonging the astronauts’ stay without a secure means of return is not an option that the Chinese space agency can afford.

Comparative Risks with Historical Missions

The current situation for the Shenzhou 21 astronauts brings to mind the experience of NASA astronauts Butch Wilmore and Suni Williams, who faced their own challenges during a mission aboard the International Space Station (ISS) in June 2024. Their ride, the Boeing Starliner, encountered issues that led to an uncrewed return to Earth in September 2024. Unlike the Shenzhou 21 crew, Wilmore and Williams had life-saving alternatives available throughout their mission, with other spacecraft docked to the ISS.

The Shenzhou 21 crew—comprised of commander Zhang Lu, 48, who previously flew on Shenzhou 15, as well as spaceflight newcomers Zhang Hongzhang and Wu Fei—currently does not have that luxury. The only crew-capable vehicle docked to Tiangong, the Shenzhou 20, is not deemed safe for use due to its damaged window, which has tiny cracks from the space debris incident. As reported by the state-run Xinhua news outlet, “The Shenzhou-20 spacecraft does not meet the requirements for the astronauts’ safe return and will remain in orbit to continue relevant experiments.”

Shenzhou 21 represents the tenth crewed mission to Tiangong, a space station significantly smaller than the ISS, weighing approximately 20% of its mass. The astronauts aboard are navigating an uncertain future, emphasizing the inherent risks of human spaceflight and the importance of robust emergency protocols. As the situation develops, the global space community will be watching closely to see how China addresses this challenging predicament and ensures the safety of its astronauts.