Following concerns about the safety of their original vehicle, three Chinese astronauts have made a safe return to Earth. The Shenzhou-21 spacecraft, recently launched, brought the crew back after issues were discovered with their assigned spacecraft.
The Shenzhou-21 return module landed successfully at 3:40 a.m. Eastern (0840 UTC, or 4:40 p.m. Beijing time) on November 14 in the Dongfeng landing area of Inner Mongolia, near the Jiuquan Satellite Launch Center. In an unusual move, the Shenzhou-20 crew returned to Earth in the very spacecraft that launched the Shenzhou-21 astronauts on October 31.
Shenzhou-20 astronauts—commander Chen Dong, Chen Zhongrui and Wang Jie—were assisted out of the return module approximately 30 minutes after landing by recovery personnel. In brief interviews conducted by state media reporters at the site, the astronauts expressed their gratitude to the nation and its space program professionals.
The initial plan had the three crew members returning to Earth on November 5. However, their departure from the Tiangong space station was delayed due to a suspected small space debris impact on their Shenzhou-20 spacecraft. The China Manned Space Engineering Office (CMSEO), the agency overseeing the country’s human spaceflight endeavors, issued an update on November 11, reporting that assessments and undisclosed contingency plans were progressing smoothly.
A notice about airspace closure surfaced on November 12, hinting at the planned landing of a Shenzhou spacecraft on November 14, though CMSEO remained silent on the matter. CMSEO later announced that the Shenzhou-21 spacecraft undocked from Tiangong at 10:14 p.m. Eastern on November 13 (0314 UTC, Nov. 14), and also revealed the reason why the Shenzhou-20 spacecraft was deemed unsafe.
CMSEO stressed their commitment to a “life first, safety first” principle. According to a CMSEO statement on November 14, “Based on preliminary analysis of photographs, design review, simulation analysis, and wind tunnel testing, a comprehensive assessment determined that the Shenzhou-20 manned spacecraft’s return capsule window glass had developed a minor crack, most likely caused by an external impact from space debris, thus failing to meet the requirements for a safe crewed return. The Shenzhou-20 manned spacecraft will remain in orbit to conduct relevant experiments.”
The Shenzhou-20 crew’s journey began on April 24 from Jiuquan aboard a Long March 2F rocket. They spent six months aboard Tiangong. The Shenzhou-21 crew arrived on October 31, and a station handover ceremony took place on November 4.
The delay resulted in the Shenzhou-20 crew becoming the first to spend more than 200 consecutive days in space. As it stands, the return of the Shenzhou-21 spacecraft leaves the current Tiangong crew without an immediate lifeboat in case of an emergency. CMSEO's next step involves launching the uncrewed Shenzhou-22 spacecraft to Tiangong for the Shenzhou-21 crew. The launch date is yet to be announced.
China’s human spaceflight program includes emergency protocols such as keeping a Long March 2F rocket and Shenzhou spacecraft ready at Jiuquan, potentially ready for launch in approximately 8.5 days. The Shenzhou-20 spacecraft will eventually be deorbited. Tiangong, a three-module space station completed in 2022, is designed to accommodate three astronauts for stays of around 180 days, and up to six astronauts for brief periods during crew changeovers.
While Tiangong can temporarily support six astronauts, with three sleeping quarters in the Wentian experiment module and three in the Tianhe core module, a larger crew would accelerate the consumption of essential resources such as water, oxygen, and food, placing additional strain on recycling and carbon dioxide removal systems.
The Shenzhou-20 incident underscores the growing problem of space debris in low Earth orbit. Both the International Space Station and Tiangong have had to maneuver to avoid potential collisions with debris. The majority of debris is too small to be tracked from the ground. Considering objects in low Earth orbit travel at roughly 8 kilometers per second, even small debris impacts can be highly energetic.
China plans to maintain a permanent crew on the Tiangong space station for at least a decade. CMSEO has commissioned the development of cost-effective cargo spacecraft to support the station, supplementing the existing Tianzhou cargo spacecraft. Furthermore, China intends to expand the orbital outpost with additional modules and a co-orbital space telescope.