Chinese astronauts inspect debris-damaged Shenzhou-20 spacecraft during spacewalk

HELSINKI — Two Shenzhou-21 astronauts embarked on the mission’s first spacewalk late Monday, inspecting and photographing a damaged spacecraft window which triggered an earlier emergency launch.

Shenzhou-21 mission commander Zhang Lu and rookie crewmate Wu Fei began an extravehicular activity (EVA) at 9:28 p.m. Eastern, Dec. 8 (0228 UTC, Dec. 9), when Zhang opened the Wentian experiment module airlock hatch and exited the Tiangong space station. 

The more than eight-hour EVA concluded at 5:42 a.m. Eastern (1042 UTC) Dec. 9, with the pair safely back inside Tiangong. Zhang and Wu, wearing Feitian EVA suits with red and blue markings respectively, were assisted by the space station’s robotic arm, crewmate Zhang Hongzhang from inside Tiangong, and teams in mission control. New, upgraded Feitian suits were delivered to Tiangong via the July Tianzhou-9 cargo mission.

The first series of tasks centered on the Shenzhou-20 spacecraft, the return module of which suffered a suspected debris impact to a viewport window, rendering the spacecraft unsafe to return its three-astronaut crew to Earth in early November. At around 12:19 a.m. Eastern, Zhang Lu approached the viewport window of the Shenzhou-20 return module while attached to the Tiandong robotic arm and photographed and assessed the damage.

China’s human spaceflight agency, CMSEO, did not publish images of the damage in its statement on the EVA. China Central Television (CCTV) published video from the spacewalk showing the astronauts preparing to leave the airlock and performing tasks outside Tiangong, but did not include footage of the damaged Shenzhou-20 spacecraft. 

The damage to Shenzhou-20 initiated a cascading series of crew transfer and launch decisions that reshaped China’s near-term human spaceflight schedule. The discovery of the tiny crack to the window—discovered during standard checks before the Shenzhou-20 crew were due to depart from Tiangong Nov. 5 at the end of their six-month-long mission—saw the crew’s return postponed, leading to the trio using the recently-arrived Shenzhou-21 spacecraft to return home Nov. 14, and the launch of the on-standby uncrewed Shenzhou-22 spacecraft Nov. 25 to provide a new lifeboat for the Shenzhou-21 astronauts. 

CMSEO stated after the Dec. 9 EVA that the Shenzhou-21 crew will take protective measures for the damaged windows of the Shenzhou-20 spacecraft as needed during future EVAs.

Zhang and Wu continued coordinated duties outside Tiangong, including installing space debris protective shielding on the space station’s exterior—a frequent task for Tiangong EVAs—and replacing the multi-layered covers for a Tiangong temperature control adapter.

The Shenzhou-21 crew launched and arrived at Tiangong Oct. 31, assuming control of the orbital outpost from the outgoing Shenzhou-20 crew. The trio will spend around six months in space before handing over to the Shenzhou-23 crew, who are expected to launch in April or May 2026. 

While the launch of Shenzhou-22 has provided a lifeboat for the Shenzhou-21 crew, the use of the standby spacecraft and its Long March 2F rocket leaves a gap in emergency launch capability. China is currently expediting its production of the Shenzhou-23 spacecraft and Long March 2F launcher, with the former expected to be delivered to Jiuquan Satellite Launch Center in January, around two months earlier than planned. 

China aims to keep the Tiangong space station permanently occupied for around a decade, while also planning to expand the facility with more modules. A co-orbiting, Hubble-class space telescope, Xuntian, is expected to launch around late 2026 or early 2027. It will be able to dock with Tiangong for repairs, maintenance and potentially upgrades.

The first Shenzhou-21 EVA comes amid a surge in Chinese launch activities, with five successful launches taking place since Dec. 5, including three Long March launches within a 24-hour period across Dec. 8-9.