Twenty-eight astronauts recently completed China's first-ever cave survival training, which took place over a one-month period, according to the China Manned Space Agency.

Organized by the Astronaut Center of China in Wulong district, Chongqing municipality, the training featured over 10 activities, including environmental monitoring, cave mapping, simulated communication between astronauts and ground control, and psychological and behavioral exercises, the agency said in a news release on Monday.

Participating astronauts were divided into four groups, each spending six days and five nights in a natural cave where the average temperature was 8 C and humidity reached up to 99 percent.

The training involved tasks such as cave exploration, scientific research, resource management and daily maintenance. The astronauts navigated extremely narrow passages, climbed and rappelled down cliffs, endured prolonged cold and damp conditions, and faced intense physical challenges. They also had to overcome psychological hurdles like fear of darkness and sensory deprivation, the agency said.

Previously, Chinese astronaut Ye Guangfu participated in a weeklong underground training in Italy organized by the European Space Agency in the summer of 2016.

In the future, the Astronaut Center of China plans to continue these rigorous training programs, both for astronauts who have not yet participated and for new recruits, to further enhance the team's ability to adapt to extreme environments and accomplish their tasks, according to the release.