Confirmation has arrived that the Shenzhou 22 spacecraft has reached the Tiangong space station with an automated docking maneuver. It launched with no crew aboard about 3.5 hours earlier atop a Long March-2F rocket from the Jiuquan Satellite Launch Center. The Shenzhou 22 was sent to the Tiangong to provide the Shenzhou 21 mission crew with a reliable vehicle to return to Earth.

The problems at the Tiangong space station began with the discovery of damage to a window on the Shenzhou 20 spacecraft, which was scheduled to return to Earth in early November with its crew, who were nearing the end of their mission. The damage was most likely caused by a tiny piece of space debris.

After days of checks and assessments, the Chinese authorities decided to return the three taikonauts to Earth on the Shenzhou 21 spacecraft. On November 14, the Shenzhou 21 returned to Earth according to the new plan. However, this meant that the taikonauts now serving on the Tiangong were left without a reliable spacecraft that would allow them to abandon the space station in case of an emergency without running serious risks during their return to Earth.

The Chinese maintain a rocket and spacecraft on stand-by for emergencies, such as a spacecraft deemed unsafe for crew transport due to damage. A launch, however, requires some days of preparation, as it must be planned with extreme care, taking into account the precise location of the Tiangong space station and all other information necessary for the flight.

This emergency launch allowed additional cargo to be sent to the Tiangong space station. The taikonauts have ample supplies of food, water, and oxygen, but there was an opportunity to send more, including fresh fruit and vegetables, which are only occasionally available. Tools were also sent to try to repair the damaged window of the Shenzhou 20 spacecraft. Evaluations regarding the spacecraft’s departure and what kind of experiments to conduct on board, including flight endurance, will likely be conducted after those repairs.

Most importantly, the taikonauts of the Shenzhou 21 mission now have a reliable spacecraft to return to Earth. This contingency proves the dangers that even tiny space debris can pose and the Chinese space agency’s ability to respond to an emergency.