Overview
- The study used a rotating 3D clinostat and a microchannel maze to simulate weightlessness and a reproductive tract on Earth.
- Human and mouse sperm showed about a 50 percent drop in successful navigation with no change in swimming speed.
- In mice, four to six hours of simulated weightlessness cut fertilization by about 30 percent.
- Embryos exposed during the first 24 hours after fertilization formed less often and developed more slowly with fewer early cells.
- Adding progesterone partly restored human sperm orientation, and researchers now plan graded‑gravity and artificial‑gravity studies to guide Moon and Mars health planning.