Lab mice who spend time in space seem to bear offspring with reduced reproductive capacity, a new study suggests. But what that might mean for human astronauts and their families is still unclear.The research, published June 30 in the journal PNAS, looked at female mice that had spent extended periods on the International Space Station (ISS). These mice had similar levels of fertility as Earth-bound mice. However, their children and grandchildren produced smaller-than-average litters, had fewer litters overall and had lower levels of key reproductive hormones, among other measurable differences. "The offspring of those that came back from space were altered in their behavior, their muscle, t...