A study published August 15 in the journal Stem Cell Reports found that mice stem cells cryopreserved in space can produce healthy offspring. According to the team, this indicates that cryopreserved germ cells can maintain fertility for at least six months– for mice. Stem cells from mice cryopreserved on the International Space Station for six months have produced healthy offspring. While the mice offspring appear normal and do not have abnormal DNA patterns, long-term health issues still cannot be ruled out. “We still have some spermatogonial stem cells frozen on the ISS, so we will continue to conduct further analysis,” says Kanatsu-Shinohara.