Sally Kristen Ride was an American physicist and astronaut. Ride joined NASA in 1978 and, at the age of 32, became the first American woman in space. She left NASA in 1987 to work at Stanford University's Center for International Security and Arms Control, and served on the committees that investigated the two American space shuttle disasters, becoming the only person to serve on both panels. She founded a company, Sally Ride Science, in 2001, and co-authored six children's science books with her life partner of 27 years, Tam O'Shaughnessy. Ride remains the youngest American astronaut to be launched into space.