Japanese researchers have determined that freeze-dried semen from mice exposed to high levels of cosmic rays on the ISS for nearly six years produced normal, unremarkable young,
The young of those mice and the third generation were also found to be normal.
The researchers wondered whether space radiation could affect the reproductive capacity of humans and animals that would like to build new life on a planet other than Earth.
To answer that question, they set up a large scientific experiment.
The results seem reassuring.
The freeze-dried mouse semen has produced quite a few normal mouse pups after six years aboard the International Space Station.
According to the researchers' calculations, freeze-dried semen could even be stored in the ISS for about 200 years without any problems.
The choice for freeze-dried semen had a practical reason: in this form the samples can be stored at room temperature for more than a year.
Non-freeze-dried sperm samples would have to be sent to the ISS in a freezer and in a rocket that is not available.
The research project began in 1997. Lead researcher Teruhiko Wakayama and his colleagues at Yamanashi University demonstrated for the first time that mice could actually be cultured from freeze-dried sperm.