A mouse spent two weeks in space, then returned to Earth and produced more pups than the average lab mouse on the ground. That's one reason researchers are interested in how the experiment informs future space biology studies. According to a report, ‘China's "space mouse" Births Third Healthy Litter,’ published by the Chinese Academy of Sciences in 2026, four mice were launched aboard the Shenzhou-21 spacecraft on October 31, 2025, as part of China's first experiment with small mammals in space. The animals lived in a specially adapted habitat for two weeks in zero gravity before returning to Earth on November 14. The experiment drew widespread attention.
Back on Earth, the female mouse became pregnant within weeks.
