185 years at 0.2c [1][2]. (No deceleration at the other end.)
[1] https://hpf.psu.edu/2026/06/30/gj-3378b/#:~:text=Introductio...
[2] https://en.wikipedia.org/wiki/Breakthrough_Starshot#:~:text=...
It absolutely does not. We don’t know if mammals can reproduce in space because we haven’t done those experiments yet. The closest we’ve come is culturing mouse embryos for four days on the ISS [1].
[1] https://phys.org/news/2023-10-mouse-embryos-grown-space-japa...