Shenzhou 21 Astronauts Face Uncertain Future Aboard Tiangong

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, 2023, for a planned six-month stay. However, their scheduled vehicle home was sent away on the evening of November 13, 2023, when the Shenzhou 20 spacecraft transported its crew back, leaving the Shenzhou 21 astronauts in a precarious situation.

The Shenzhou 20 spacecraft had been deemed unsafe for flight following damage from a space debris strike. Consequently, the astronauts aboard Shenzhou 21 are now reliant on contingency plans for their return. Fortunately, China maintains a Long March 2F rocket and an additional Shenzhou spacecraft at the Jiuquan Satellite Launch Center, ready to launch under such circumstances. According to reports by SpaceNews’ Andrew Jones, this standby lifeboat could be deployed to the Tiangong station within as little as 8.5 days if necessary.

Chinese space authorities have indicated that the Shenzhou 22 spacecraft will also be launched to the station, presumably without a crew on board. While no specific timeline has been provided, officials noted the launch would occur “at an appropriate time in the future.” The urgency surrounding this situation underscores the need to minimize risk for the astronauts, as each day spent in orbit without a safe return vehicle heightens their vulnerability.

The current predicament of the Shenzhou 21 astronauts echoes the experience of NASA astronauts Butch Wilmore and Suni Williams, who faced their own challenges aboard the International Space Station (ISS) during the first crewed mission of Boeing’s Starliner capsule in June 2024. Although the astronauts faced issues with their spacecraft, they remained safe due to the presence of other operational lifeboats docked to the ISS. In contrast, the Shenzhou 20, the only crew-capable vehicle currently at Tiangong, has sustained damage, rendering it unfit for a safe return flight.

According to the state-run Xinhua news outlet, the China Manned Space Agency confirmed that the Shenzhou 20 spacecraft will remain in orbit for ongoing scientific experiments despite its compromised condition. The Shenzhou 21 mission marks the tenth crewed journey to the Tiangong station, which is approximately 20% the mass of the ISS.

The crew of Shenzhou 21 includes commander Zhang Lu, 48, a veteran astronaut who previously flew on Shenzhou 15 in 2022, along with first-time space travelers Zhang Hongzhang and Wu Fei. Wu holds the distinction of being the youngest member of China’s astronaut corps, further emphasizing the significance of this mission in the context of China’s expanding presence in space exploration.

As the Shenzhou 21 astronauts await further developments, the international space community watches closely, recognizing both the risks and the achievements inherent in human spaceflight. With plans for future missions in place, the situation serves as a reminder of the complexities and uncertainties faced by astronauts in orbit.