The inside story of China's first space rescue mission

In November 2025, China's manned space program carried out its first-ever emergency launch in response to a critical incident aboard the Chinese Space Station. A crack was discovered in an external porthole window of the Shenzhou-20 spacecraft, which was preparing to return its crew. The damage was likely caused by a micrometeoroid impact. Within just 20 days, the program managed an unprecedented mobilization, compressing standard procedures to launch the backup Shenzhou-22 spacecraft. 

Meanwhile, the Shenzhou-20 crew safely returned to Earth using the already docked Shenzhou-21 vehicle. The rapid and successful launch and docking of Shenzhou-22 demonstrated the maturity and resilience of China's spaceflight capabilities, setting a new international standard for handling in-orbit emergencies.

Incident overview and initial assessment

On November 4, 2025, during final preparations for their return to Earth, the Shenzhou-20 astronaut crew discovered an anomaly on a porthole window. A crack was found on the edge of the glass. Using both a camera and the space station's 40x microscope, the crew captured detailed images of the defect from multiple angles. The damaged glass was identified as the outermost layer of the spacecraft's window, a critical component that serves a thermal protection function. 

Following the discovery, the China Manned Space Engineering Office announced that the Shenzhou-20 spacecraft was suspected to have been struck by a micro-debris fragment. After three days of exhaustive analysis, which reportedly left personnel with precious little time for sleep, the team reached a definitive conclusion. According to the China Aerospace Science and Technology Corporation (CASC), "the glass was indeed impacted, it was damaged, and the crack was penetrating – the glass had cracked all the way through."

Based on this assessment, the consensus was that using the damaged Shenzhou-20 craft for the return trip would pose a significant risk to astronauts. 

The emergency response strategy

The decision to ground Shenzhou-20 immediately triggered the program's emergency protocols, which focused on launching a backup vehicle.  

The incident served as the first real-world test of China's "launch one, back up one, rolling backup" strategy. This protocol ensures that for every crewed mission in orbit, another rocket and spacecraft are kept ready at the launch site as a rescue vehicle. The Shenzhou-22 spacecraft was the designated backup asset already on standby.  

On November 8, 2025, the command headquarters officially decided on a 16-day launch flow for Shenzhou-22, targeting a November 25 launch date. Executing a launch in 16 days, rather than the typical 30-45 day cycle, required significant process optimization and rigorous quality control.  

Technical execution and overcoming challenges

To save time, teams shifted from traditional "serial" processes to a "parallel" model. Key steps, such as the rocket's base-stage assembly, escape tower assembly, and final spacecraft-rocket integration, were conducted simultaneously.  

The launch site was already managing a busy schedule with over ten satellite launches planned for November. To clear the necessary facilities for Shenzhou-22, testing for the Shijian-30 satellite, which was occupying a shared test building, was compressed from five days to two by using three daily shifts.  

Despite the compressed timeline, officials confirmed that no testing procedures were cut. The 16-day schedule was feasible because the backup vehicle had already completed its initial standby preparations, allowing for a truncated final testing phase that still covered all required items.  

Crew operations and successful return

A central part of the emergency plan was ensuring the safe return of the Shenzhou-20 crew. The crew's return was delayed by nine days, during which they collaborated closely with the Shenzhou-21 crew (already on the station) and ground control.  

The crew used the Shenzhou-21 spacecraft for their return. As astronaut seats and pads are custom-fitted, the two crews worked together to reconfigure and adjust the spacecraft for its new passengers. The Shenzhou-20 crew received training from the Shenzhou-21 crew on the specific operations of their return vehicle and performed adaptation tests.  

On November 14, 2025, the Shenzhou-20 crew departed the space station. Their return utilized a 3-circle rapid return trajectory for the first time, a faster alternative to the standard 5-circle profile used by Shenzhou-20. At 16:40 on November 14, the Shenzhou-21 spacecraft landed safely at the Dongfeng site, with all three astronauts in good condition.  

The Shenzhou-22 mission

With the Shenzhou-20 crew safely on the ground, the focus shifted entirely to the launch of their replacement return vehicle.  

The Shenzhou-22 mission was unique in its dual role. It was launched as a "space lifeboat plus supply ship." Its primary purpose was to dock with the station and serve as the return vehicle for the Shenzhou-21 crew. As the first of a new batch, the Shenzhou-22 spacecraft incorporated several technical improvements for enhanced functionality and performance.  

Although launched without a crew, it carried the largest-ever volume of upward cargo for a Shenzhou mission. This included astronaut food, fresh fruit and vegetables and a specialized device to address the crack in the Shenzhou-20 window.  

The spacecraft was launched with its standard launch escape tower. Though not needed for an unmanned flight, removing it would have altered the rocket's aerodynamics and mass, introducing unacceptable risks.  

Continuation of backup protocol

Even as Shenzhou-22 was being launched, the "rolling backup" system was already in motion. The next backup vehicle, Shenzhou-23, along with its carrier rocket, was reported to be in the final assembly and testing phase, preparing for transport to the launch site to assume its standby role.