Do you think astronauts only need to overcome zero gravity and operate complex equipment? 

Darkness, sensory deprivation, isolation and sudden risks are also part of space missions. That's why China launched an unconventional training program, deep inside a cave in southwestern China. 

The cave's natural conditions – cold, humid, dark and confined – mirror space, pushing astronauts beyond simulators to train endurance, teamwork, decision-making and mental resilience. From underground to outer space, this downward journey prepares them to go farther.