Meet the First American Woman to Walk in Space

Kathryn Sullivan's interview is part of TIME Firsts, a multimedia project featuring 46 groundbreaking women. Watch the rest of the videos at Time.com/Firsts. Buy the book at the TIME Shop.

When Kathryn Sullivan joined the Astronaut Corps in 1978, she was breaking ground for women in space — and luckily she wasn't alone.

“NASA had the wisdom to bring in a critical mass — six women, three African Americans, an Asian,” Sullivan said. “There was a cohort, and we could build a bit of an alliance to tackle some of the issues that come along with adding new people to a close-knit culture.”

That cohort knew the importance of what they were doing.

“All six of us in that first batch of women felt a self-imposed pressure,” she said. “One of us would be the first to fly, another would be the first to do a spacewalk — which only a small group of the Astronaut Corps gets to do. We knew our performance would have a big influence on the prospects of the women who would come after us.”

Even with that pressure, the specifics of being a “first” at something wasn't paramount to Sullivan.

“I was thrilled to be tapped for a spacewalk, but the ‘first female spacewalker’ tag really didn’t matter to me,” she said. “It was my first spacewalk.”