Sally Kristen Ride (May 26, 1951 – July 23, 2012) was an American astronaut and physicist. Born in Los Angeles, she joined NASA in 1978 and became the first American woman in space in 1983. Ride was the third woman in space overall, after USSR cosmonauts Valentina Tereshkova (1963) and Svetlana Savitskaya (1982). Ride remains the youngest American astronaut to have traveled to space, having done so at the age of 32. After flying twice on the Orbiter Challenger, she left NASA in 1987.