Lost in space: Microgravity makes sperm lose their sense of direction

Making babies in space may be more complicated than expected, as new research shows sperm struggle to navigate in microgravity. Scientists found that while sperm can still swim normally, they lose their sense of direction without gravity, making it harder to reach and fertilize an egg. In lab experiments simulating space conditions, far fewer sperm successfully made it through a maze designed to mimic the reproductive tract, and fertilization rates in mice dropped by about 30%.