
Cosmic parenthood in doubt as space-like microgravity halves sperm navigation
New microgravity experiments using a tiny obstacle course showed human and mouse sperm navigated about 50% less effectively in space-like conditions, resulting in roughly a 30% drop in fertilization. While some sperm still reach the egg and may form higher-quality embryos, embryo development in weightlessness could pose major challenges, suggesting space reproduction may be possible only for the fittest sperm and with careful embryo protection as NASA pursues Moon and Mars settlements.











