Today, 33-year-old air force pilot Liu Yang is in space, having been rocketed there on Saturday — along with two male colleagues — for a docking mission. Yang is China's first woman in space, and she'll be there for about a week. Incidentally, on this day in 1983, Sally Ride became the first American woman in space. She flew on the space shuttle Challenger twice, and was on the ground training to go up a third time when the Challenger exploded in 1986. In all, Ride logged around 345 hours in space. Although she retired from NASA in 1987, she's still campaigning for humans to explore the universe — she's written or co-written five books on space, aimed at children, with the goal of encouraging children to study science; she's also interested in attracting more women to the sciences in general. Check out Sally Ride Science for more!