According to Japanese researchers, “space sperm” that has been freeze-dried and stored in gravity-free conditions in space has passed the fertility test- producing healthy mice. Transporting Earth seeds into space is therefore, in theory, possible.
A team of Japanese researchers have shown that sperm that has been freeze-dried and stored in the gravity-free conditions of space remains fertile.
According to the Proceedings of the National Academy of Sciences, the experiment was performed in the International Space Station (ISS), where mouse sperm samples were freeze-dried and stored for nine months and then sent to Earth again.
The DNA was reportedly a bit damaged from the trip, however “fertilization and birth rates were still similar to healthy “ground control” mice.”
The scientists from the University of Yamanashi say the egg may have repaired the sperm damage. “If sperm samples are to be preserved for longer periods in space, then it is likely that DNA damage will increase and exceed the limit of the [egg] oocyte’s capacity for repair.”
“If the DNA damage occurring during long-term preservation is found to have a significant effect on offspring, we will need to develop methods to protect sperm samples against space radiation, such as an ice shield,” they said.
This means that transporting seeds away from Earth is a feasible possibility. We could also use the Moon as a location for a “back-up” sperm bank in case disaster ensues on Earth.
Sustaining Life in Space
The conditions on space make sustaining life incredibly challenging. On the ISS, there is about 100 times more radiation, with an average dose of 0.5mSv daily- this can damage DNA inside sperm cells.
Reduced gravitational force also impacts the sperm. According to a study in 1988, a bull semen sample was sent on a rocket into space to orbit the Earth, finding that sperm tend to swim a lot faster in lower gravity. Another study showed that in a 15-day orbit, “fish eggs could be fertilized and develop normally.”