Chinese Spacewalkers Inspect Damaged Shenzhou-20 Window

Two Shenzhou-21 taikonauts conducted a spacewalk yesterday that included inspecting the damaged window on Shenzhou-20 that remains docked to the Tiangong space station. Last month the Shenzhou-20 crew had to return to Earth using Shenzhou-21’s spacecraft because the window is cracked, apparently by a piece of space debris. China later launched Shenzhou-22 without a crew for Shenzhou-21 to use to return to Earth next spring at the end of their 6-month mission.

Zhang Lu and Wu Fei spent about eight hours outside the space station, ending at 6:45 pm Beijing time (5:45 am EST) on December 9 according to China’s government news agency Xinhua.

The China Manned Space Agency (CMSA) said the two taikonauts inspected Shenzhou-20’s “viewport window” and “may also undertake protective operations” on the window.

In a thread on X, space journalist Andrew Jones summarized a report from China’s CCTV chronicling what happened over the 20 days between when the crack was discovered and the empty Shenzhou-22 was launched. Chinese experts determined the crack penetrates the first of three layers of glass and a “patch” was sent up on Shenzhou-22 to protect the window when Shenzhou-20 makes an uncrewed return to Earth at some point in the future.

Shenzhou-22 brings food, fresh produce, and a patch to help protect Shenzhou-20’s damaged window. Later, Shenzhou-20 will perform an uncrewed return to collect real-world data on how cracked structures behave during reentry.

— Andrew Jones (@AJ_FI) December 1, 2025

The crack is thought to be the result of a space debris strike. The spacewalkers also installed a “debris protection device” for the space station as have previous Chinese spacewalkers.

Space debris is a growing problem in low Earth orbit (LEO) where both Tiangong and the International Space Station operate. Tiny asteroid fragments, micrometeoroids, are another hazard. Travelling at orbital velocity of 17,500 miles per hour, even the smallest object can pose substantial risk. Russia’s Soyuz MS-22 spacecraft lost all its coolant into space after apparently being struck by a micrometeoroid and, like Shenzhou-20, was deemed unsafe to return its crew to Earth. An empty replacement, Soyuz MS-23, was launched in that case as well. The uncrewed Russian Progress MS-21 cargo spacecraft also was struck by either space debris or a micrometeoroid while docked at the ISS in February 2023.