Technicians found tiny cracks in the Shenzhou-20 return capsule viewport, likely caused by a hit from orbital debris, prompting a delay to the crew's Nov. 5 return. The three astronauts later returned safely aboard Shenzhou-21, which launched Oct. 31. CMSA said Shenzhou-20 will remain in orbit and Shenzhou-22 will be launched at a later date. Experts warn that rising satellite launches and past anti-satellite tests, such as China’s 2007 Fengyun-1C destruction, increase collision risk in low Earth orbit.
Space Debris Cracks Shenzhou-20 Window — Crew Delayed but Returned Safely
Technicians found tiny cracks in the Shenzhou-20 return capsule viewport, likely caused by a hit from orbital debris, prompting a delay to the crew's Nov. 5 return. The three astronauts later returned safely aboard Shenzhou-21, which launched Oct. 31. CMSA said Shenzhou-20 will remain in orbit and Shenzhou-22 will be launched at a later date. Experts warn that rising satellite launches and past anti-satellite tests, such as China’s 2007 Fengyun-1C destruction, increase collision risk in low Earth orbit.
09:47 PM, 11/14/2025Science
Orbital debris damages Shenzhou-20 viewport, forcing crew swap
Chinese space officials postponed the planned Nov. 5 return of three astronauts after technicians discovered tiny cracks in the return capsule viewport of the Shenzhou-20 spacecraft, which had been docked at the Tiangong space station since April. The China Manned Space Agency (CMSA) said the damage was most likely caused by an external impact from orbital debris.
CMSA: "Tiny cracks were identified in the return capsule's viewport window, most probably caused by external impact from space debris."
Because the capsule no longer met safety standards for crew re-entry, CMSA kept the Shenzhou-20 vehicle in orbit so the station crew could continue experiments while a replacement return vehicle was arranged.
Fortunately, the three astronauts later returned safely to Earth, using Shenzhou-21, which had launched to Tiangong on Oct. 31 with a fresh three-person crew. The handover allowed the earlier team to land in China’s Inner Mongolia Autonomous Region. CMSA has said Shenzhou-22 "will be launched at an appropriate time in the future," according to Xinhua.
Space debris — fragments of spent rockets, defunct satellites and other remnants that range from millimetres to metres in size — poses a growing hazard to long-duration operations in low Earth orbit. At orbital velocities measured in the tens of thousands of miles per hour, even millimetre-scale pieces can strike with energy comparable to a high-velocity projectile, puncturing heat shields, windows or other critical hardware.
Efforts to remove debris are still nascent, so orbital platforms including the International Space Station regularly perform avoidance maneuvers and thruster firings to lower collision risk. As commercial launches accelerate and thousands more satellites are deployed, collision risk is expected to rise before meaningful cleanup measures scale up.
The incident also highlights geopolitical factors. In a commentary for The Conversation, Lincoln Hines of the Georgia Institute of Technology noted the irony that China’s spacecraft was damaged by debris given the country’s role in producing a large share of orbital fragments — notably the 2007 anti-satellite test that destroyed a defunct Fengyun-1C weather satellite and generated the single largest debris cloud in history, with more than 3,000 tracked pieces still in orbit.
The Shenzhou-20 window cracks underscore how vulnerable crewed missions remain to space debris and why improving debris tracking, avoidance procedures and active removal technologies is becoming an urgent priority for all spacefaring nations.