Sally Kristen Ride was finishing her Ph.D. in physics at Stanford University in 1977 when she saw an article in the student newspaper saying that NASA was looking for astronaut candidates and that for the first time, women could apply. When she blasted off aboard the space shuttle Challenger 40 years ago on June 18, 1983, she became the first American woman—and, at 32, the youngest American—in space. Sally's historic flight made her a symbol of the ability of women to break barriers and a hero to generations of adventurous young girls. She flew on Challenger again in 1984 and later was the only person to serve on both panels investigating the nation's space shuttle disasters—the Challenger explosion in 1986 and the breakup of the shuttle Columbia on reentry in 2003. Sadly, Sally Ride died on July 23, 2012, after a 17-month battle with pancreatic cancer.