In a groundbreaking experiment, mouse embryos were thawed and successfully cultivated on the International Space Station (ISS), suggesting the potential for human reproduction in space, according to a team of Japanese scientists.

The group, led by Teruhiko Wakayama, a professor at the University of Yamanashi's Advanced Biotechnology Centre, in collaboration with the Japan Aerospace Space Agency (JAXA), dispatched frozen mouse embryos to the ISS via a rocket in August 2021.

Astronauts employed a specialized device to thaw the early-stage embryos, nurturing them on the station for four days. Remarkably, the embryos grown under microgravity conditions progressed normally into blastocysts, the precursor cells that develop into both fetus and placenta. As reported in a study published online in the scientific journal iScience, the experiment unequivocally demonstrated that gravity had minimal influence on the embryos. Moreover, the analysis of the blastocysts returned to Earth revealed no significant alterations in DNA or genes.

This groundbreaking achievement was hailed as "the first-ever study that shows mammals may be able to thrive in space" in a joint statement by the University of Yamanashi and the national research institute Riken. It marked "the world's first experiment that cultured early-stage mammalian embryos under complete microgravity on the ISS." The next step in the research will involve transplanting the ISS-cultivated blastocysts into mice to determine if they can lead to normal mouse births.

This research holds significant importance for future space exploration and colonization missions. NASA's Artemis program, for instance, plans to send humans back to the moon to acquire long-term living skills, with an eye toward eventually preparing for Mars exploration, projected to occur in the late 2030s.