A Japanese team of researchers have enabled healthy baby mice to be born on the International Space Station (ISS) using freeze-dried sperm stored in space. The experiment shows that life away from Earth is feasible, with sperm banks potentially being made on the Moon. It also raises the questions of whether mammals, including humans, can permanently live and procreate in space.

The freeze-dried mouse sperm samples were stored on the space station for nine months before being sent back down to Earth and thawed at room temperature. Although the sperm DNA was slightly damaged by the trip, it still did the job of fertilising mouse eggs and creating healthy “space pups”, with fertilisation and birth rates similar to healthy “ground control” mice.

The space pups had only minor differences in their genetic code and grew to adulthood, with a few being allowed to mate and became mums and dads themselves.

This is not the first time such experiments have been conducted. In 1988, German researchers sent a sample of bull semen into orbit on a rocket and discovered that sperm were able to swim much faster in low gravity. Another space test showed fish eggs could be fertilised and develop normally during a 15-day orbital flight, suggesting a brief trip into space might not be too harmful for reproduction.

Work still needs to be done to ensure that such an experiment would work in space.

Students going for Medical and Biological Sciences should look further into the risk of radiation damage on the Moon and the facilities that would help to protect sperm, eggs and embryos from harm. They should also explore the medical and psychological questions raised.

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