Astronaut Sally Ride, who was the first U.S. female astronaut in space, died Monday. (DAVE PICKOFF/ASSOCIATED PRESS)

By becoming the first U.S. woman—and youngest astronaut—in space, Sally Ride, who died Monday from pancreatic cancer, was a pioneer and a trailblazer.

But it was what she did with the rest of her career that made her a leader.

She challenged people to speak difficult truths, and embraced those who did. As one of the people investigating the Challenger explosion in 1986 (she was the only person to sit on panels investigating both the Challenger the Columbia tragedy), she was known for asking tough questions. In an obituary, the New York Times shares the story about how Ride hugged Roger Boisjoly, the engineer who had been shunned for warning his bosses and NASA that O-rings could fail in cold weather, after his testimony.

She never allowed the attention from her achievement to be focused on herself. “At her request, NASA denied all requests for licenses to sell posters, T-shirts and other merchandise bearing her name and likeness,” the Post reports. She rarely gave interviews, avoided the public spotlight and told reporters around the time of her historic trip: “It’s too bad this is such a big deal. It’s too bad our society isn’t further along.” It was about the journey, not herself.

Most of all, she inspired others to dream big and imagine themselves in roles they previously couldn’t. Some of this was passive inspiration; the natural byproduct of Ride’s historic launch. (Ask any woman who was a kid in the early ‘80s who she wanted to be when she grew up, and I’ll bet you hear Sally Ride more than a few times.) But she also worked actively to inspire young girls, creating Sally Ride Science, an education company dedicated to supporting kids’ interest in science. The organization’s corporate mission “is to make a difference in girls' lives, and in society's perceptions of their roles in technical fields.”

By definition, pioneers are leaders—the first in their fields, leading the way for others to follow. But being first is not necessarily, on its own, evidence of practicing leadership. Ride did both. Even if her historic first is what we’ll most remember, her lifetime of leadership may have touched us even more.

Read also: Sally Ride’s obituary

View Photo Gallery: Sixteen prominent women who broke gender barriers and stepped into historic leadership roles.

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