Three Chinese astronauts are currently stationed aboard the Tiangong space station without a designated return vehicle after their original spacecraft was damaged by a suspected space debris strike. China's space agency is now preparing an uncrewed replacement mission, scheduled to launch later this month.
The incident has left the Shenzhou 21 crew, who arrived at the station on October 31, reliant on a rescue launch to ensure their safe return to Earth. The replacement spacecraft, Shenzhou 22, is slated to lift off from the Jiuquan Satellite Launch Center on or around November 25.
Key Takeaways
- Three astronauts on China's Tiangong space station are without a return spacecraft.
- Their original capsule, SZ-20, sustained window damage from a suspected space debris impact.
- A replacement uncrewed mission, Shenzhou 22, is scheduled for a November 25 launch.
- The incident highlights the growing danger posed by orbital debris to crewed space missions.
A Damaged Ride Home
The situation began after the spacecraft that brought the previous crew (Shenzhou 20) to the station was inspected. Officials discovered cracks in a window on the SZ-20 capsule, leading them to deem it unsafe for the high-stress conditions of atmospheric reentry. This damage is believed to have been caused by an impact with a small piece of orbital debris.
As a result, the returning Shenzhou 20 crew used the spacecraft originally intended for the current Shenzhou 21 crew. This necessary safety measure left the new arrivals—commander Zhang Lu, Zhang Hongzhang, and Wu Fei—without a functional "lifeboat" docked at the station.
The Growing Threat of Space Debris
Orbital debris, often called "space junk," includes everything from defunct satellites to tiny flecks of paint shed from rockets. Even minuscule objects can cause catastrophic damage when traveling at orbital velocities, which can exceed 17,000 miles per hour (27,000 km/h). This incident serves as a stark reminder of the increasing risk debris poses to all space activities.
The Rescue Mission Plan
China's Manned Space Agency (CMSA) has initiated its emergency response protocol. According to officials, a Long March 2F rocket and a replacement Shenzhou spacecraft are kept on standby for precisely this type of contingency. While these systems can theoretically be ready for launch in as few as 8.5 days, the mission requires precise timing.
The November 25 launch date allows for the Tiangong space station's orbit to align perfectly with the launch site in Inner Mongolia. This ensures the Shenzhou 22 can efficiently rendezvous and dock with the station. By the time it launches, the crew will have been without a dedicated return craft for nearly three weeks.
More Than Just a Rescue Craft
The CMSA plans to use the uncrewed mission to deliver additional supplies. The Shenzhou 22 will be packed with extra food and other essential cargo for the crew, who are at the beginning of a planned six-month mission.
The need for resupply was likely made more urgent because the previous crew's stay was extended for several days while the situation was assessed, potentially depleting on-station resources faster than anticipated.
Did You Know? The Shenzhou 22 mission was originally scheduled for the second quarter of 2026. The current emergency has accelerated its timeline by more than a year, demonstrating the flexibility of China's crewed space program.
A Recurring Problem in Orbit
This is the second time in two years that a space station crew has been left temporarily stranded. In a separate incident in 2024, two NASA astronauts, Butch Wilmore and Suni Williams, flew to the International Space Station (ISS) aboard Boeing's new Starliner spacecraft.
After the Starliner experienced technical issues with helium leaks and thrusters, NASA decided it was not safe to return the astronauts. They remained on the ISS for nearly nine months until a SpaceX Crew Dragon capsule was sent to retrieve them.
"These incidents have been a 'massive wake-up call' for the need for a dedicated international space rescue service," some spaceflight experts have noted, highlighting a critical gap in current space operations.
However, establishing such a service faces significant geopolitical hurdles. Current U.S. law largely prohibits direct cooperation between NASA and China's space agency, making a universal rescue protocol difficult to implement. As more nations and private companies venture into orbit, the risk of similar events will only grow, increasing pressure for new international safety standards and collaborative rescue capabilities.