The cause was pancreatic cancer, her company, Sally Ride Science, announced on its Web site. Dr. Ride, a physicist, flew on the shuttle Challenger on June 18, 1983, and on a second mission in 1984. She was also, at 32, the youngest American in space. Dr. Ride later became the only person to sit on both panels investigating the catastrophic shuttle accidents that killed all astronauts on board — the Challenger explosion in 1986 and the Columbia crash in 2003.

Dr. Ride was finishing studies at Stanford — degrees in physics and astrophysics (and also English) — and looking for a job when she saw a newspaper advertisement that said NASA was accepting astronaut applications. She looked at the qualifications and said, “I’m one of those people,” she told The New York Times in 1982.

She applied, and made the cut.

“The women’s movement had already paved the way, I think, for my coming,” she said.