Your SIN is a 'master key.' Here's why you must protect it

A new study from NASA , conducted over several years of long-duration spaceflights on the International Space Station, has found that more than half of U.S. astronauts started noticing changes in their vision after more than six months aboard the ISS. Here’s what to know. What does the study say? “Many found that, as their mission progressed, they needed stronger reading glasses,” the study says. “Researchers studying this phenomenon...